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Feb 17, 2012
Send abstract titles to the appropriate Sectional VP.
See the Call for Abstracts for details.
March 1, 2012
Deadline for submissions for the High School Student Video Essay Competition
See the Instructions for submission details and the Application Form.
March 14, 2012
Abstract submission deadline.
See the Call for Abstracts for details.
April 16, 2012
Annual FSHS meeting registration deadline. Register Electronically (through ASHS) or via Printable Form
May 10, 2012
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Events

F.S.H.S.

June 3 - 5 2012
FSHS Annual Meeting - Delray Beach Marriott - Beach Resort

Feb. 16, 2012
Stone Fruit Postharvest Handling Workshop, CREC, Lake Alfred, FL. Register here.
April 1 - 4, 2012
International Symposium on Mechanical Harvesting & Handling Systems of Fruits and Nuts. CREC, Lake Alfred FL.
July 27 - 29, 2012
Florida Small Farms and Alternative Enterprises Conference, Osceola Heritage Park, Kissimmee, Florida
July 31 - Aug. 3, 2012
ASHS Annual Conference, InterContinental Miami, Florida
Aug. 15 - 16, 2012
Citrus Expo, Lee Civic Center, Ft. Myers, Florida
Aug. 23, 2012
Packinghouse Day, Citrus REC, Lake Alfred, Florida
Sept. 27 - 29, 2012
The Landscape Show, Orange County Convention Center (OCCC), Orlando, Florida
July 22 - 25, 2013
ASHS Annual Conference, Desert Springs JW Marriott Resort & Spa, Palm Desert, California
Also check-out:
UF/IFAS Extension Web Calendar
Florida Citrus Mutual Calendar
FNGLA Events Calendar

2010 Proceedings - FSHS Vol. 123

Abstracts

Preliminary Field Evaluation of Jatropha (Jatropha curcas L.) under South Florida Environmental Conditions

Jonathan H. Crane, Wagner A. Vendrame, Wanda Montas, Ania Pinares, and Edward A. Evans

Page 1-4

Seventeen jatropha selections were planted 25 June 2009 at the Tropical Research and Education Center to evaluate their growth, development, and adaptation to a warm subtropical climate and calcareous soil conditions. Plants were grown from seed and 1 to 12 plants were planted per accession. Trunk diameter and plant height, and number of seeds and dry weight of seeds produced were periodically recorded. The mean percent change in plant height over the first 8 months ranged from 46% (Brazil-KB) to 86% (India). The mean percent change in trunk diameter was from 6% (Brazil-Plain) to 45% (Guatemala). Fruit were first harvested about 5½ months after planting. The mean number of fruits produced per plant varied by accession, with Ethiopia producing the least (0.3 fruits/plant) and Brazil-Plain producing the most (43 fruits/plant). Mean dry weight of harvested seed varied, with Ethiopia producing the least (0.6 g seed/plant) and India the most (94.3 g seed/plant).
Visit the FSHS Proceedings Section for access to the complete paper. Access to the three most recent volumes of the FSHS Proceedings require a membership. For more information about becoming a member, please visit the MEMBERSHIP section.

Results of the 2009 ASBVd Survey of Avocado Accessions of the National Germplasm Collection in Florida

Cecile L. Tondo, Raymond J. Schnell, and David N. Kuhn

Page 5-7

The performance of satsuma (Citrus unshiu Marc.) cultivars Owari and Brown Select on Poncirus trifoliata (L.) Raf. (standard and Flying Dragon) was evaluated from 2007 to 2009 at the North Florida Research and Education Center–Quincy. The orchard, established in 2004, consisted of trees planted 4.57 and 6.10 m within and between rows, respectively. Trees were not subjected to freeze protection and withstood minimum temperatures of –9.3 °C (15.3 °F) without apparent damage. Tree size (canopy area), yield, and fruit quality data were analyzed as a 2 × 2 factorial design. Average yield per tree across all genotypes was 12, 8, and 60 kg in 2007, 2008, and 2009, respectively. Yield was not significantly affected by scion or rootstock in 2007 or 2008, although both scion and rootstock effects were significant in 2009, with higher yield for ‘Brown Select’ scions and P. trifoliata (standard) rootstocks. For all years, fruit weight was significantly greater for ‘Brown Select’ (average = 152 g) than ‘Owari’ (average = 119 g). Soluble solids of orange juice were higher for satsuma on P. trifoliata Flying Dragon (average = 9.7 °Brix) compared to P. trifoliata standard (average = 9.1 °Brix) rootstocks. Fruit of ‘Owari’ were more acidic than ‘Brown Select’ in 2007 and 2008. In 2009, both cultivar and rootstock had a significant effect on tree canopy area [‘Brown Select’ scions and P. trifoliata (standard) rootstocks were larger]. Yield efficiency (yield/canopy area) was affected by scion (‘Brown Select’ trees were higher), but not by rootstock. In 2009, fruit number per tree was highest for ‘Brown Select’/P. trifoliata (standard) The satsuma is a specialty crop with potential for expansion in acreage for the northern Gulf Coast region.

The presence of avocado sunblotch viroid (ASBVd) infection among the avocado (Persea americana Mill.) accessions in the National Germplasm Repository at Miami (NGR–Miami) was established in previous studies. An ASBVd specific reverse transcription-polymerase chain reaction (RT-PCR) protocol was used to detect the viroid. Surveys performed in 1996 and in 2000 found that the proportion of ASBVd positive accessions remained unchanged at 19% during that time period. The object of the current study was to assess the spread of infection, if any, and the rate and direction of transmission. For this purpose the collection was screened again for ASBVd in 2009. The germplasm collection increased from 403 to 505 trees. Fifty newly infected trees were detected. Forty-eight percent of the newly infected plants were found to be adjacent to previously infected plants, adjacent to plots from which infected plants had been removed, or adjacent to other newly infected plants that are adjacent to previously infected plants or contaminated plots. No pattern in direction of spread was discerned for non-adjacent new infections. The proportion of plants found to be positive for the viroid in the current study is 21%. Fourteen plants previously found to be infected were found to be negative in this survey. The proportion of infected plants (historically and at present) in the current collection is 24%. The increase in ASBVd infections reinforces the importance of establishing back-up collections at different locations. Establishment of collections at the NGR in Hawaii is currently under way.

Visit the FSHS Proceedings Section for access to the complete paper. Access to the three most recent volumes of the FSHS Proceedings require a membership. For more information about becoming a member, please visit the MEMBERSHIP section.

Performance of ‘Owari’ and ‘Brown Select’ Satsumain North Florida on Standard and Flying Dragon Poncirus trifoliata Rootstocks

Peter C. Andersen and Brent V. Brodbeck

Page 8-10

The Role of Research and Extension in Establishment of a Florida Stone Fruit Industry
Mercy A. Olmstead

Page 11-13
The University of Florida stone fruit breeding program has successfully bred low-chill varieties for over 50 years, with extensive plantings in low-chill production areas worldwide. Although a small stone fruit industry (~4,000 acres) was originally established in northern Florida, successive cold events in the 1980s reduced plantings to less than 500 acres. Recent releases from the stone fruit breeding program now target central and south-central Florida for orchard development, where the risk of spring freeze events is minimized. Short fruit development periods, non-melting flesh texture, and a unique marketing window in April and May with little worldwide competition for fresh fruit will allow growers to take advantage of favorable market prices and maximize profits. However, cultivation of stone fruit is intensive and requires constant monitoring to manage both abiotic and biotic production challenges. In addition, economic analyses, development of marketing tools, fertilization techniques, frost protection, and cultural management are important issues that need industry input as research and extension programming expands. As stone fruit acreage increases in Florida, communication between the research and extension community, producers, marketers, and buyers will enable development of applied projects that successfully address industry challenges.

Damage to Low-chill Peach and Plum Trees from Ice Accumulation during Severe Winter Freezes in North and North-central Florida
Jeffrey G. Williamson, Paul Miller, Robert C. Hochmuth, and Linda Landrum
Page 14-17
Extreme cold during Jan. and Feb. 2009 required overhead irrigation for freeze protection of flowers and young fruit in the orchards at the Plant Science Research and Education Unit (PSREU) in Citra, FL, and the North Florida Research and Education Center–Suwannee Valley near Live Oak, FL. Severe freezes on 22 Jan. and 6 Feb. at both locations, with minimum temperatures of approximately 23 °F at Citra and 21 °F at Live Oak, and 10- to 11-h durations of sub-freezing temperatures each night, resulted in heavy ice loads. Additionally, there were 9 other freeze/frost events at Citra and over 20 events at Live Oak between 15 Jan. and 4 Mar. where overhead irrigation was used. Low-chill peach, nectarine, and plum cultivars were evaluated for limb breakage from excessive ice loads that resulted from freeze protection with overhead irrigation at both locations. Broken limbs with diameters greater than 7/8 inch (peach) or 1/2 inch (plum) and split scaffold limbs were counted on individual trees at Citra. Sample size per cultivar ranged from 2 to 47 trees. Trees were also rated for percent full canopy and percent full crop just prior to harvest. Peach and nectarine cultivars at Citra varied in the number of limb breaks and split scaffolds. ‘FlordaPrince’ had the highest incidence of scaffold limb splits (almost 3 per tree) while ‘UFSun’ had the highest incidence of limb breaks (approximately 5.5 per tree). No scaffold splits were observed for plum; however, the incidence of broken limbs was high (4 to 6.8 per tree) depending on cultivar. Percent full canopy just prior to harvest ranged from 60% (‘UFSun’ and ‘Gulfking’) to 80% (‘Earligrand’, ‘Sunraycer’, ‘FlordaPrince’, and ‘UFBeauty’) and percent full crop ranged from 10% (‘UFSun’) to 70% (‘Earligrand’ and ‘FlordaKing’). The greatest incidence of scaffold limb breaks at Live Oak was found in ‘Gulfruby’ plum (2.5 breaks per tree) and ‘UFQueen’ nectarine (3.0 breaks per tree).

Deciduous Fruit Crop Demonstration Area at Water Conserv II Project in Central Florida
Gary K. England and Ryan A. Atwood
Page 18-19
There is increased interest in the evaluation of alternative crops grown in the central Florida region as a possible replacement for citrus. With the cooperation of the Water Conserv II Project, the Mid Florida Citrus Foundation and University of Florida (UF) IFAS established a Deciduous Fruit Crop Demonstration Area where alternative crops were planted and have been evaluated as potential selections for producers in the area. Fruit crops that have been evaluated include pecan, persimmon, fig, blueberry, peach, plum, and grapes. In 2006, a decision was made to evaluate some of the newer promising fruit crop cultivars from the University of Florida breeding programs. The first phase of the project began with the planting of seven peach, three nectarine, and two plum cultivars in mid-Dec. 2006, followed by the addition of three plum cultivars in Summer 2007. Dr. Dennis Gray from UF provided three numbered muscadine and one bunch grape cultivars that were established in Summer 2007. A container-grown blueberry planting including some of the cultivars adapted to central Florida was planted in Spring 2008. Some potential persimmon and pomegranate cultivars were added in 2008 and 2009, respectively. Observations of appropriate production practices and field day opportunities, which introduced local growers to some of the crops, have taken place. In Spring 2010, a trial to evaluate the effect of different peach and nectarine thinning techniques (no thinning, 4, 6, and 9 inches) was conducted.

Summer 2009 Blueberry Herbicide Evaluations
Gary K. England, William M. Stall, and Ken Muzyk
Page 20-22
There continues to be a trend of growers starting or expanding blueberry plantings in west-central Florida. Managing weeds in blueberry plantings continues to be one of the main production challenges that growers face. A majority of the commercial blueberries are produced in pine bark culture. Drawing from the results of several trials that were conducted between 2007 and early 2009 on blueberry plantings in pine bark culture, two blueberry herbicide studies were initiated to evaluate some of the promising compounds under summer conditions. Just after postharvest pruning, a trial evaluating four labeled products and one promising herbicide was initiated in a 4-year-old southern highbush blueberry planting in pine bark culture in June 2009. At 61 d after treatment (DAT) rating, treatments containing Surflan and Chateau were providing excellent control of garden spurge (Chamaesyce hirta; EPHHI), significantly better than the other treatments. The trend indicated that the same treatments resulted in the best control of spiny amaranth (Amaranthus spinosus; AMASP) and Brazilian pusley (Richardia brasiliensis; RCHBR). Rely 200 herbicide is approved as a non-selective postemergence herbicide alternative to products containing glyphosate. A trial was established in a new blueberry planting in pine bark culture to evaluate an experimental additive for Rely 200 that may enhance the control of perennial weed species. At 34 DAT evaluation, Rely 200 at 5 pt/acre + AA10717 at 5 fl oz/acre was providing good common bermudagrass (Cynodon dactylon; CYNDA) control that was significantly better than Rely 200 at 5 pt/acre alone.

Blueberry Gall Midge: A Key Pest of Rabbiteye Blueberries
Oscar E. Liburd and Craig R. Roubos
Page 23-25
Blueberry gall midge, Dasineura oxycoccana (Johnson) is a key pest of rabbiteye blueberries that produces dramatic yield losses in the southeastern United States. Blueberry gall midge is a relatively minor pest of southern highbush blueberries where injury is largely confined to vegetative buds. Adults emerge in early spring and females oviposit between developing flower and leaf bud scales. Larvae feed inside the buds, causing deformities in developing leaves; damage to flower buds causes necrosis and frequently results in flower bud abortion. To determine the influence of temperature on survival and rate of development, we exposed flower buds to various temperatures in environmental chambers. Larval and pupal development at the lowest temperature tested suggests that growers need to apply insecticides for blueberry gall midge early in the season while temperatures are still low.

Assessment of Genetic Diversity among Selected Raspberry Cultivars
Gohar Umar, Hemanth Kn. Vasanthaiah, Devaiah Kambiranda, Sheikh M. Basha, Bobby R. Phills, and Wayne Hunter
Page 26-28
Growing raspberries in southern United States is a challenging task as they are high chill-loving plants. Cultivation of raspberry in Florida is significantly hampered due to prevailing hot and humid conditions. The characteristics of raspberry cultivars have been categorized based on morphological descriptions that are dependent on the environment. With this view our program is geared toward identifying low chill/high temperature raspberry genotypes. In this regard, genetic diversity among raspberry cultivars being evaluated in our breeding program for low-chill/high temperature tolerance was assessed employing molecular techniques. A high quality DNA was isolated from raspberry leaf tissue and subjected to molecular analysis. DNA typing was carried out using RAPD assay. Of the 100 primers screened, 10 primers yielded 142 usable DNA bands. Pairwise comparisons of unique and shared amplification products were used to construct a phylogenetic tree using Euclidean linkage distances that clearly separated low- and high-chill raspberry genotypes. These data showed the potentiality of RAPD markers for assessing genetic diversity among raspberry cultivars. Further studies coupled with field analysis would aid in identifying low-chill/high temperature fruit set raspberry genotypes useful for developing raspberry cultivars suitable for Florida.

Development of New Muscadine Wine Grapes
Zhongbo Ren, Jiang Lu, Xia Xu, and Fitz Bradley
Page 29-31
Three white and five red wine muscadine grapes were selected from 6650 seedlings of FAMU’s muscadine breeding program. Horticultural characteristics, wine evaluation scores, and wine browning data indicate that these selections have advanced horticultural and/or wine characteristics over premium wine cultivars Carlos and Noble, making these the new premium wine grapes in the future.

Genetic Variation in Sucrose Metabolizing Enzymes among Six Muscadine Varieties
Devaiah Kambiranda, Hemanth Kn. Vasanthaiah, and Sheikh M. Basha
Page 32-34
Accumulation of sugars is an important process that occurs during grape berry development. Sugars are transported into the berry mainly in the form of sucrose and are broken down into glucose and fructose by the enzymes invertase and sucrose synthase. In this study we have determined changes in the soluble sugar content, and invertase and sucrose synthase enzyme activity levels during different stages (30, 60, 90 d, and ripe) of berry development among selected muscadine varieties. Soluble sugar content varied among muscadine genotypes, with the highest being in ‘African Queen’ and lowest in ‘Carlos’. Expression of invertase enzyme was highest in 90-d-old berry as well as in ripened berry among the muscadine varieties tested. Sucrose synthase activity was highest in 90-d-old berries among ‘Summit’, ‘Scarlet’, and ‘African Queen’ cultivars. In contrast, ‘Noble’, ‘Carlos’, and ‘Welder’ contained the highest sucrose synthase activity in 60-d-old berries. These data suggest that in muscadine grape berry invertase and sucrose synthase activities are positively correlated with high berry sugar content.

Screening of Fruit Rot Diseases in Muscadine Grape (Vitis rotundifolia Michx.)
Xia Xu, Jiang Lu, Barbara J. Smith, Zhongbo Ren, Fitz Bradley, and Meliss a Cadet
Page 35-38
Muscadine grape (Vitis rotundifolia Michx.) is one of the major fruit crops in Florida. Although far more resistant to most diseases than bunch grapes (Vitis vinifera, Vitis labrusca, or their derivatives), muscadine grape suffers extensive economic losses every year due to fruit berry rotting diseases that significantly reduce fruit yield and marketability for both wine and fresh consumption. Three berry rot diseases, including black rot (Guignardia bidwellii f. muscadinii), bitter rot (Greeneria uvicola), and macrophoma rot (Botryosphaeria dothidea) were evaluated in 45 commercially available muscadine cultivars at the research vineyard of Florida A&M University in order to develop a disease-resistant breeding program. The cultivars were randomly arranged in three blocks and data were collected in five randomly picked clusters on each tree according to Kummuang et al. (1996) in the 2009 harvesting season. The results indicated that bitter rot was the most prevalent fruit rot disease that occurred on 29 muscadine grape cultivars, followed closely by black rot. The incidence of macrophoma rot was low. The most susceptible cultivar to bitter rot and black rot diseases was ‘Early Fry’ with 33.33% and 17.65% berry infection rate, respectively. Twelve cultivars showed no symptoms of bitter rot, black rot, and macrophoma rot diseases. They are ‘Alachua’, ‘Albermarle’, ‘Black Beauty’, ‘Digby’, ‘Fry’, ‘Granny Val’, ‘Golden Isle’, ‘Higgins’, ‘Noble’, ‘Pride’, ‘Sterling’, and ‘Supreme’. Co-occurrence of ripe rot on the same berry often makes identification of bitter rot more difficult, especially during the later harvest season.

Modeling Loosening of Sweet Orange with CMNP: Variation in Fruit Detachment Force
Sunehali Sharma, Robert C. Ebel, and Kelly T. Morgan
Page 39-43
The abscission agent 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) was applied at 200 and 300 ppm to ‘Hamlin’ trees in three trials from December through the end of January and to ‘Valencia’ in three trials from March through April to determine the spatial and temporal variation in fruit detachment force (FDF) and fruit drop up to 5 d after application. Average FDF varied from 18 to 97 N for ‘Hamlin’ and 42 to 119 N for ‘Valencia’ before CMNP was applied. A univariate analysis was used to determine the upper and lower 99% confidence limits and means for every sampling date. Linear regressions fitted to the three regressions for each cultivar and CMNP concentration were statistically significant at the P < 0.05 or P < 0.01 level. The slopes and CMNP concentrations were subjected to ANOVA, and the lack of an interaction indicated that the rate of loosening was similar regardless of initial FDF. The slopes for the lower and upper confidence limits and mean were similar for ‘Valencia’, but the slope of the lower confidence limit was lower than for the upper confidence limit and mean for ‘Hamlin’, indicating that ‘Hamlin’ fruit with low initial FDF loosen slower than fruit with higher initial FDF. An exponential function was found to fit well to fruit drop over time with regression coefficients ranging from 0.75 to 0.99. We propose that the relationships developed here would be useful in developing a predictive tool for mechanical harvesters with catch frames that minimizes the sum of fruit drop and fruit left in the tree after harvest.

Induction of Autotetraploids in Pummelo (Citrus grandis L. Osbeck) through Colchicine Treatment of Meristematically Active Seeds In Vitro
Divya Kainth and Jude W. Grosser
Page 44-48
Autotetraploids in pink/red-fleshed pummelo selections 5-1-99-2, C2-5-12, and UKP-1 (all derived from Hirado Buntan pink pummelo) were produced by treating the germinated seeds with different colchicine concentrations of control, 0.1%, 0.2%, and 0.3% for different treatment durations of 12 and 24 h. The seedlings emerged when put on rooting media under sterile conditions. The seedling ploidy was determined via flow cytometry at a stage when the seedlings had 1–2 expanded leaves. Higher colchicine concentrations and treatment durations decreased the survival rates of the seedlings compared with the lower concentrations and smaller treatment durations. The seeds that received higher concentrations and longer durations turned brown completely or had a dead meristematic bud. A similar trend was observed for the number of mutated shoots (tetraploids and mixoploids). Colchicine treatment decreased the growth rate of the affected seedlings. The frequency of autotetraploidy varied among the selections. Selections 5-1-99-2, C2- 5-12, and UKP-1 successfully produced 2, 1, and 3 autotetraploids and 1, 2, and 4 mixoploids, respectively. The most efficient colchicine concentration was 0.1%. Reversion of the tetraploids and mixoploids into diploids was also observed. The stable pink/red-fleshed tetraploid plants generated should be useful as breeding parents in grapefruit/pummelo improvement programs. Use of monoembryonic tetraploids in interploid citrus crosses eliminates the need for embryo rescue to recover seedless triploid progeny; until now, no pink or red-fleshed monoembryonic pummelo parents are available.

Spatial Variability of Leaf Wetness Duration in Citrus Canopies
Veronica N. Santillan, Clyde W. Fraisse, Natalia A. Peres, James C. Colee, and Amy Cantrell
Page 49-55
Leaf wetness duration (LWD) is a key parameter in some disease warning systems and as an input to biological modeling of infection of many plant diseases in crops. The main objective of this study was to determine the spatial heterogeneity of LWD within citrus canopies during summer and winter conditions. The spatial variability of LWD was evaluated in citrus trees in central Florida at 12 canopy positions during Aug. 2008 and Feb. 2009. The analysis of LWD measurements revealed statistical heterogeneity among sensor heights and horizontal positions. LWD was significantly higher (P < 0.0001) at the top canopy compared to the middle and bottom positions during rainy days and no-rain days. The differences in mean daily LWD between top and bottom canopy during a 31-d period of time in the summer were 2.9 and 2.5 h during no-rain and rain days, respectively. The difference in mean daily LWD during a 30-d period in the winter with no-rain days was 2.6 h. The comparison by linear regression analysis between sensors within the canopy and a sensor installed at 30 cm (0.98 ft) over turf grass in a nearby Florida Automated Weather Network (FAWN) station showed that the station sensor provides accurate estimates of LWD at the top of the canopy. These findings accentuate the importance of accounting for the impact of spatial heterogeneity when LWD is used as input to disease-warning systems.

Variation in Florida Orange Yields Over a 37-Year Period: A Standardized Evaluation
L. Gene Albrigo and Marina Burani-Arouca
Page 56-58
To monitor changes in Florida orange production per mature tree over time, a method was devised to standardize the number of bearing trees each year to account for variation in the number of mature and young bearing age trees which have lower yields than mature trees. This was accomplished by estimating young tree production as a percentage of mature tree yields and adjusting values in each year to reflect mature tree equivalents (MTE). Orange trees in Flatwoods areas were assigned partial values for their yield potential from 5 until 10 years of age compared to mature tree yields, and young trees in Ridge areas were assigned partial mature tree values from age 5 until 13 years of age depending on studies of yield to tree age in these two major production areas. MTE values were divided into the reported annual yields of early-midseason (E-M) (primarily ‘Hamlin’) and late (primarily ‘Valencia’) orange cultivars. Freeze events were also rated for severity and all these values, including total Florida citrus yield in boxes are reported in graphic form for the years 1963 through 1999. Excepting 1964, early‑midseason orange yields ranged from 2.7 to 5.5 boxes/MTE and late orange yields ranged from 2.3 to 4.4 boxes/MTE for the period 1963 through 1999. There was an increase in productivity per tree from 1963 until 1970 with no perceptible increase after that. Comparing MTE yields in 2008, 3 to 4 years after the 2004–05 series of hurricanes indicated that Ridge yields were similar to pre-hurricane yields, but yields in Flatwoods areas were low. These results can be useful for evaluating trends in yields over time, the impact of weather events and assessing yield potential from predicted and actual levels of bloom each year.

Interaction of CMNP Application and Harvest Date of ‘Hamlin’ Sweet Orange
Robert C. Ebel, Kelly T. Morgan, and Fritz M. Roka
Page 59-61
This study was conducted to determine the change in mechanical harvest efficiency over time of sweet orange treated with the abscission agent 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP). CMNP was applied in December on ‘Hamlin’ at 0 and 300 mg·L–1 in a carrier volume of 2806 L·ha–1. The trees were harvested 2, 3, 4, and 6 d after CMNP application with a pull-behind canopy shaker operating at 3.7 Hz and with a tractor speed of 1.6 km·h–1. Fruit detachment force of CMNP-treated fruit declined to 39 N, which was 40% lower than the controls, by 4 d after CMNP application. The percent of fruit drop increased to 5% for CMNP treated fruit by 4 d compared to the controls that were significantly lower with 1% drop. The CMNP × harvest day interaction for the percentage of the crop removed by the harvester was not significantly different. The CMNP main effect mean was significant with CMNP removing 73% of the crop compared to 68% for the controls. The widest separation between CMNP treated and controls trees for the amount of fruit left in the trees after mechanical harvest occurred on day 4, where only 23% of the crop had to be gleaned for CMNP-treated trees compared to the controls that required 36% of the crop to be removed by hand. This study demonstrated that CMNP was active up to 4 d after CMNP application with the concentration and carrier volume of CMNP as used here and with air temperatures optimum for loosening (>15.6 °C) for most of the loosening period.

Citrus Stumps Sprout Control
Stephen H. Futch and Shawron Weingarten
Page 62-64
To assess the effectiveness of Remedy Ultra® (triclopyr), two studies were conducted during 2008–10 to control citrus stump sprouting after HLB-infected tree removal. The first study (2008–09, Arcadia) examined various application rates of Remedy (25%, 50%, and 75% mixed with diesel fuel) whereas, the second study (2009–10, Arcadia and Lake Placid) looked at the impact of delaying application of Remedy on the control of sprout formation. During the first study, 12 of the 15 (80%) untreated stumps sprouted. Sprouts were noted over the study period with 0, 5, 3, 1 and 3 of the 15 stumps sprouting initially at approximately 30, 60, 90, 120, and 150 d after tree removal, respectively. All treated stumps, regardless of the treatment rate, remained sprout free during the study period. For the second study, treatments of Remedy were applied at 25% or 50% solution mixed with diesel fuel at time of clipping, 24, 48, and 72 h later and compared to untreated controls. At Lake Placid, 7 (100%) untreated stumps sprouting by 150 d after tree removal. Four stumps within the 56 treated stumps had root sprouts but not from the treated stump. Remedy Ultra was slightly less effective in controlling sprouts when applied at the 25% Remedy/75% diesel than at the 50% rate. Delaying application and using the lower herbicide concentration rate also had a slight negative impact on sprout control. At Arcadia, 86% of the untreated stumps sprouted within 90 d of clipping with only one treated stump sprouting. These studies support the use of Remedy Ultra as an effective tool in controlling sprout formation and the importance of timely application to stumps, within 72 h of clipping, for sprout control.

Alion 200 SC: A Promising New Herbicide for Weed Management in Florida Citrus
Stephen H. Futch, Mike Edenfield, and John Curtis
Page 65-66
Alion 200 SC® (indaziflam) is a promising new herbicide under development by Bayer CropScience for proposed use in perennial tree crops, including citrus. The new herbicide is for the preemergence control of broadleaf weeds and annual grasses. Alion 200 SC belongs to the alkylazine chemical class of herbicides. Indaziflam inhibits cell wall biosynthesis and acts on meristematic cell growth affecting germinating weeds prior to emergence. The herbicide can be used alone or in tank-mix combinations with various pre- and/or postemergence products. In 2009, two field trials were initiated in a young citrus grove in St. Lucie and DeSoto counties. Alion 200 SC was applied at 5.13 to 6.84 oz/acre in tank-mix combinations with glyphosate and compared with existing registered residual herbicide tank-mixes. In St. Lucie County, Alion 200 SC, when applied with glyphosate, provided greater than 83% overall weed control at 4 months after application at both 5 and 6.5 oz/acre. In DeSoto County, Alion 200 SC provided 90% control of all weeds at 88 d after treatment (DAT) when applied at 6.84 oz/acre.

Estimating Relative Nutrient Uptake by Mature Citrus Trees in Field Conditions
Kirandeep K. Mann, Laura J. Waldo, Kevin Hostler, Rajinder S. Mann, and Arnold W. Schumann
Page 67-73
Knowledge of nutrient uptake rates by tree roots is of fundamental importance to develop a citrus fertilization program. However, measuring the nutrient uptake by mature trees in field conditions is difficult. Nutrient uptake by intact roots of mature citrus trees was estimated using the nutrient depletion method, wherein intact roots were separated from the soil and placed in a nutrient solution of known composition. Thereafter, the nutrient concentrations of the solution were measured at a series of time intervals (0, 4, 8, 12, 24, 48, 72, 96, 120, and 144 h) to determine the nutrient depletion curve. The solution volume was maintained with deionized water using constant head Mariotte tubes. Our results showed that the diurnal and seasonal changes in soil temperature and evapotranspiration were responsible for the corresponding variations in nutrient uptake. The time periods, determined by inflection points, beyond which further nutrient uptake was negligible were very low (12–51 h) for different months, revealing that the nutrient uptake by roots is very fast for the first few hours and is negligible after a certain level of depletion is reached. These results suggested the need of frequent small fertigations to supply the tree roots with a continuous source of nutrients to sustain high uptake rates, to prevent nutrient losses to the environment, and to increase nutrient use efficiency. Relative uptake of different nutrient ions also varied across different months. Collectively, our results provide a basis for the development of guidelines for fertigation in an Advanced Citrus Production System and fertilizer formulations to meet the plant’s requirements.

Phosphite Is Not a Good Source of Phosphorus Nutrition for Citrus Rootstock Seedlings
Fernando C.B. Zambrosi, D. Mattos Jr., and J.P. Syvertsen
Page 74-77
Phosphite (PO3; Phi), a reduced form of P, can prevent plant infection by Phytophthora spp. and thereby reduce crop loss in many agricultural commodities including citrus. Although some commercial formulations of Phi have a nutritional label as a source of P, Phi can have negative effects on plant growth. We tested the nutritional value of Phi in Carrizo citrange (CC) and Smooth Flat Seville (SFS) citrus rootstock seedlings growing in either aerated hydroponic nutrient solution or in fertigated native Candler sand soil in a greenhouse. There were four P treatments: No P; 0.5 mmol·L–1 PO4 (Pi); 0.25 mmol·L–1 PO4 + 0.25 mmol·L–1 PO3 (PPi+Phi); or 0.5 mmol·L–1 PO3 (Phi). Leaf net gas exchange was measured near the end of the experiment and after 83 days, plants were harvested, separated into leaves, stems, and roots and growth parameters were evaluated. Overall, hydroponically-grown roots were longer and thinner than sand-grown roots so hydroponically-grown plants had a lower root/shoot dry weight ratio than sand-grown plants. Growth of the two rootstocks responded in a similar way to P treatments but leaf N and chlorophyll were lower in SFS than in CC leaves. The Pi seedlings had the highest leaf P, net assimilation of CO2 (ACO2) and total growth while the No P seedlings had the highest root/shoot dry weight ratio. Growth responses, leaf N, and ACO2 of the PPi+Phi treatment were intermediate between the Pi and Phi treatments. Total plant growth was positively related to leaf P in Pi plants but growth was negatively related to leaf P in Phi plants. Phi reduced root and shoot growth even though seedlings had higher leaf P than the No P seedlings. Phi plants had comparable leaf chlorophyll and ACO2 to No P plants but leaf N was reduced by Phi. Thus, Phi was not a source of nutritionally available P for seedlings of citrus rootstocks.

‘Parson Brown’ Sweet Orange Performance in a Rootstock Planting
William S. Castle and James C. Baldwin
Page 78-81
‘Parson Brown’ sweet orange [Citrus sinensis (L.) Osb.] is a well-known early-maturing seedy variety whose importance has slowly declined over time. Its usefulness as a commercial variety has been based on its better juice color and soluble solids content compared to the most common early-season orange, ‘Hamlin’. The juice traits of ‘Parson Brown’ have fit into the production and marketing profile of various companies; thus, an unreplicated rootstock planting was initiated in 1988. The planting was located near Basinger, FL, on the property of a grower-cooperator. Bud sources of PB-S-F-56-2-XE infected with citrus tristeza virus were used to propagate trees on 19 rootstocks. A single double-row bed (≈100 trees) was planted with trees of one rootstock in a site of Valkaria fine sand soil. The trees were spaced 10 × 25 ft. In some instances, a second bed or only a row or partial row of a rootstock was planted. Yield was measured annually along with juice quality for 9 years between the 1992–93 and 2000–01 seasons. Yield and juice quality were also measured among trees on five additional rootstocks in adjacent blocks. Tree survival was >80% except for those trees on Rusk citrange [C. sinensis × Poncirus trifoliata (L.) Raf.] (73%) and Changsha mandarin (C. reticulata Blanco) (72%). Tree height after 13 years ranged from 6.3 ft (Hybrid 1573-26 Poncirus trifoliata × ‘Ridge Pineapple’ sweet orange) to 14.9 ft (Vangasay lemon; C. jambhiri Lush.). Cumulative yield ranged from 9.6 (hybrid 1573-26) to 29.0 boxes/tree (Changsha mandarin). Tree height was significantly correlated with cumulative yield (r = 0.72) and cumulative pounds-solids/acre (r = 0.69). Cumulative pounds-solids/acre (PS/acre) was highly correlated with cumulative yield (r = 0.96). Thus, the high-yielding, tall trees on Changsha mandarin rootstock produced the largest cumulative PS/acre (26,073); however, high-yielding smaller trees on other rootstocks with high quality juice such as Rusk citrange (22,493 PS/acre) and the Rangpur × Troyer hybrid (20,155) were also among the most productive trees.

An Economic Analysis of the U.S. Orange Juice Tariff and the Competitiveness of Florida Growers and Processors
Robert A. Morris and Ronald P. Muraro
Page 82-86
Although Sao Paulo, Brazil has a climate and soils conducive to producing juice oranges, prior to the 1970s, Brazil was a relatively minor producer of processed oranges and orange juice (Table 1). However, a devastating Florida freeze in 1962, and subsequent freezes in the 1970s and 1980s created an opportunity for Brazil to expand its orange and orange juice production. Most of this production was exported (Table 1), primarily to the U.S. and Western Europe. A climate where freezes do not occur along with cheaper land and labor enabled Brazil to continue its expansion, until by the 1990s, Brazil was by far the largest orange juice producer in the world (Fig. 1), producing almost twice the amount of oranges and orange juice as Florida. In fact, without the protective U.S. tariff on imported frozen concentrated orange juice (FCOJ), the Florida processed orange industry would probably either be much smaller that it is or out of business. This paper shows how this tariff has been reduced by trade legislation and by inflation and the impact than it has had on the Florida processed orange industry.

Effect of Salicylic Acid on Oxidative Metabolism during Xanthomonas citri subsp. citri Infection of Grapefruit
Naveen Kumar, Robert C. Ebel, and Pamela D. Roberts
Page 87-91
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is one of the most devastating diseases of citrus in Florida, especially for grapefruit, which is highly susceptible to the disease. There has been much interest in chemicals that induce systemic acquired resistance (SAR). Salicylic acid is an endogenous compound known to be part of the SAR mechanism. A strain of bacterial canker was injected into leaves of grapefruit either alone or with salicylic acid (SA) and oxidative metabolism was evaluated over time. We found that Xcc manipulates H2O2 metabolism by suppressing the activity of SOD and increasing the activities of catalase, ascorbate peroxidase, and peroxidase, which collectively lowered the H2O2 concentration. Salicylic acid treatment transiently restored the activities of SOD and APOD, but was not sufficient to restrict Xcc growth in vivo.

Streptomycin and Copper Formulations for Control of Citrus Canker on Grapefruit
James H. Graham, Megan M. Dewdney, and Monty E. Myers
Page 92-99
Control of citrus canker (caused by Xanthomonas citri subsp. citri) on grapefruit is required to reduce blemishes on fresh fruit. The objective was to evaluate formulations, rates, duration of residues for copper materials, combinations of copper materials and streptomycin, and application timing for effective canker control on young, fruiting grapefruit trees. Copper applications were made at 21-d intervals starting at spring flush in March until fruit were fully expanded in October. The period of fruit susceptibility to canker was established by applying sprays at 21-d intervals through the fruit growth period, with separate treatments ending spray application at each interval so that duration of protection varied and number of applications ranged from 3 to 11. The risk and predisposing factors for fruit phytotoxicity were also assessed. In addition, the residual activity of Kocide 3000 (copper hydroxide, Dupont) on fruit, as affected by the adjuvant polymer delivery system (PDS), was measured at 7, 14, and 21 d after application. Copper formulations containing copper hydroxide or basic copper sulfate (metallic rates of 0.67 to 1.12 kg/ha), varied from low to moderately effective for canker control depending on late-season, wind-blown rains. Copper pentahydrate, at a lower metallic copper rate/ha per application, provided equivalent control to other copper formulations. Streptomycin (FireWall, Agrosource, Inc.), alone or with a reduced rate of Kocide 3000, in July and early August gave equivalent control to Kocide 3000 alone. Copper phytotoxicity risk coincided with accelerated fruit growth after summer rains. Greater canker susceptibility of fruit in later season is likely because more prolonged opening of stomates in cooler weather may enhance bacterial entry, when coincident with more numerous windblown rain events. The only factor that led to significant reductions (P < 0.0001) in copper residue per fruit surface area over time was the Kocide 3000 concentration. PDS had no effect on the residue.

Effect of Stimplex® Crop Biostimulant on Drought Tolerance of ‘Hamlin’ Sweet Orange
Timothy M. Spann and Holly A. Little
Page 100-104
‘Hamlin’ sweet orange trees on ‘Carrizo’ citrange and ‘Swingle’ citrumelo rootstocks were treated weekly with Stimplex® crop biostimulant (5 mL/L) as either a soil drench or foliar spray. Half of the trees in each treatment were subjected to drought stress (irrigated at 50% of evapotranspiration) while the other half remained fully irrigated (100% ET). Results showed that Stimplex®-treated drought stressed trees on both rootstocks had significantly more total growth than untreated drought stressed trees, but did not achieve the same total growth as well irrigated trees. The maintenance of growth by applications of Stimplex® under drought stress conditions was found to be independent of carbon fixation as photosynthesis was depressed in all drought stress trees regardless of treatment. The Stimplex® effect may have been related to a small, but significant, improvement of plant water relations. However, the magnitude of this change doesn’t appear to fully explain the Stimplex® effect, suggesting that hormonal or other plant metabolite changes may be involved.

A Comparison of Common and Different Volatiles in “White” Guava and ‘Valencia’ Orange Leaves
Ebenezer Onagbola, John Smoot, Lukasz Stelinski, and Russell Rouseff
Page 105-108
Static head-space volatile extraction was conducted to concentrate ‘Valencia’ orange and guava leaf volatiles, which were subsequently analyzed using gas chromatography–mass spectrometry (GC-MS). Forty-seven volatiles were identified in both guava and ‘Valencia’ leaves. There were 35 volatiles unique to each leaf type and 12 volatiles in common. Guava leaf volatiles consisted primarily of esters whereas ‘Valencia’ leaf volatiles consisted almost exclusively of terpenes. For guava, there were 20 esters, 13 terpenes/sesquiterpenes, 7 aldehydes, 2, ketones, 2 alcohols, 2 furans, and one acid. ‘Valencia’ leaf volatiles consisted of 33 terpenes/sesquiterpenes, 7 alcohols, 4 aldehydes, and 3 esters. Of the 12 volatiles in common, 8 were terpenes, 3 were aldehydes, and one alcohol. Identification was based on matching sample MS fragmentation patterns with those in the NIST library as well as matching literature standardized retention index values. Identifications were confirmed by matching observed fragmentation patterns and retention values with those of known standards run under identical conditions. The volatile profiles from guava and ‘Valencia’ orange leaves were profoundly different.

Ground Application of Foliar Insecticides to ‘Valencia’ Oranges for Control of Diaphorina citri Kuwayama (Hemiptera: Psyllidae)
Jawwad A. Qureshi*, Barry C. Kostyk, and Philip A. Stansly
Page 109-112
The Asian citrus psyllid Diaphorina citri Kuwayama is an economically important insect pest of citrus due primarily to its role as vector of Candidatus Liberibacter asiaticus, a bacterium that causes huanglongbing or citrus greening, a devastating disease of citrus. Insecticidal control is needed to reduce vector populations and slow the spread of huanglongbing. Therefore, foliar sprays of broad spectrum and selective insecticides, both with and without adjuvants, were evaluated against ACP in 14-year-old ‘Valencia’ orange trees during the growing season. Delegate WG, Requiem 25 EC, Micromite 80 WGS, Movento 240 SC, and Portal 0.4 EC applied with FL-435-66 spray oil, Movento 240 SC with Induce and 435 oil applied alone during bloom in March were all effective in reducing psyllid populations for up to two months compared to the untreated control. Orocit was less effective than 435 oil in enhancing the effectiveness of Micromite 80 WGS. The addition of 435 oil enhanced the effectiveness of Actara 25 WG in June and Movento 240 SC + 435 oil was not different from 435 oil alone. Treatments of Actara 25 WG + 435 oil, Agriflex + 435 oil, and Warrior 1SC + Actara 25 WG were all equally effective and reduced psyllid populations for up to 5 weeks. In an August experiment, Delegate WG + 435 oil or Induce and Kocide, Movento 240 SC + 435 oil, Requiem 25 EC + 435 oil or alone, Sil-Matrix and 435 oil alone all reduced psyllid adults for 2 to 3 weeks compared to the untreated control. Requiem 25 EC with 435 oil or alone, 435 oil alone, Sil-Matrix and Delegate WG + Induce were less effective than other treatments against nymphs. Danitol 2.4 EC, Warrior 1SC, Dimethoate 4 EC, Lorsban 4 E, and Imidan 70 W all applied alone in September provided effective psyllid control for up to 5 weeks. Treatment effects on adults were more pronounced and longer lasting than those seen on immatures, in part because of new flush growth. Consequently, the magnitude and duration of psyllid reduction did not compare with that observed applying foliar sprays during the dormant winter period when trees were not producing new growth upon which psyllids depend to mature eggs and for oviposition. Therefore, adults should be monitored regularly and targeted with insecticides at times when trees are not producing new growth.

Possible Tolerance to Huanglongbing in Sweet Orange
R.H. Brlansky, W.S. Castle, and S.B. Garrett
Page 113-114
Sweet orange cultivars account for approximately 80% of the total acreage of citrus in Florida. With the spread of huanglongbing (HLB) throughout the Florida citrus industry, yields of sweet orange have been affected. Research was initiated to examine the susceptibility of various commercial sweet orange cultivars to HLB. In greenhouse tests, most commercial sweet orange cultivars tested were found susceptible to graft inoculation with HLB-affected budwood. However, a high percentage of seedlings of a midseason cultivar continued to test PCR negative for Candidatus Liberibacter asiaticus (Ca. Las.) a full year after inoculation. The inoculum-containing budwood in all test plants sprouted, grew, and tested PCR positive for the bacterium assuring that the test plants were inoculated. Psyllid transmission tests to a limited number of the seedlings again produced results that numerous seedlings of the cultivar were not infected. This sweet orange cultivar may have some tolerance to Ca. Las. infection as compared to other sweet orange cultivars which are normally infected by graft inoculation in 3–4 months. The most important transmissions should be done using psyllids since this is the normal way of transmission in the field. Work is continuing on this cultivar grafted on various rootstocks.

Evaluation of Candidatus Liberibacter asiaticus Titer in Field-infected Trifoliate Cultivars: Preliminary Evidence for HLB Resistance
Ed Stover, Robert Shatters, Jr., Greg McCollum, David G. Hall, and Yongping Duan
Page 115-117
Huanglongbing (HLB) and Asian citrus psyllid (ACP) are widespread at the Ft. Pierce USDA citrus grove, which is managed primarily as a site for research on HLB control and resistance. The variety collection at this grove includes rootstock cultivars grown as scions and grafted onto Sun Chu Sha, and it has become apparent that many trifoliate hybrids have much weaker symptoms of HLB than the monofoliate rootstock suckers. Therefore Poncirus trifoliata and its hybrids were tested for Candidatus Liberibacter asiaticus (CLas )16S rDNA by qPCR. In Nov. 2009 random quadrant leaf-samples and a diagnostic “most symptomatic leaf” sample were collected from the test tree canopies, along with a random sample and diagnostic sample from rootstock suckers. Data were expressed as abundance of CLas relative to citrus dehydrin. The two P. trifoliata had non-detectable or low CLas abundance, as did two citranges, except that diagnostic samples and rootstock samples from the same citranges had a very high CLas titer. Variability was observed in relative CLas abundance among the 10 citranges tested and all showed high CLas in rootstock suckers. The data suggest that Poncirus and some Poncirus hybrids tolerate and/or suppress CLas even when grafted onto a high-titer source, and encourage further work on identifying and characterizing HLB resistance in Poncirus and its hybrids.

Monitoring Trees Infected with Huanglongbing in a Commercial Grove Receiving Nutritional/SAR Foliar Sprays in Southwest Florida
Bob Rouse, Pam Roberts, Mike Irey, Maury Boyd, and Tim Willis
Page 118-120
Citrus growers Maury Boyd and Tim Willis have had success in maintaining Huanglongbing (HLB) infected trees using a cocktail mix of nutrients and SAR (Systemic Acquired Resistance) inducing materials. The Orange Hammock grove in Felda, FL, was first confirmed to have trees infected with HLB in 2006. Since 2006 the trees have been maintained and kept productive with an excellent crop of fruit in 2010. Two plots of ‘Valencia’ on Swingle citrumelo rootstock containing 100 trees (10 rows of 10 trees per row) each were PCR tested in 2008 and in 2010. One plot contained mature trees planted in 1992 and the other plot of younger trees planted in 1999. All trees in both plots were rated in 2010 for symptoms of HLB using a 0 to 5 scale where 0 = tree vigorous, no symptoms of HLB to 5 = tree in permanent decline. At the same time, leaf samples were collected from each tree and processed by real-time PCR for detection of the HLB bacteria at the U.S. Sugar (both years) and HLB Diagnostic lab at SWFREC (2010 only). Results indicated that the percentage of HLB positive trees in the young trees increased from 81% in 2008 to 100% in 2010. The mature trees tested 40% positive in 2008, and were 92% positive in 2010. In 2010, the disease severity on young trees using the 0 to 5 scale rated 50% of the trees as 3 or greater (3 = moderate decline; symptoms of HLB). The disease rating on mature trees was less severe by comparison with less than 20% rated 3 or above.

Spectral Evaluations for Developing Optical Methods of Huanglongbing (HLB) Detection in Citrus Orchards
Sindhuja Sankaran and Reza Ehsani
Page 121-123
Huanglongbing (HLB) is a devastating citrus disease that threatens the citrus industry in Florida. Several efforts are ongoing to control and contain this disease to protect the citrus industry. Among different approaches, detection of HLB is one of the critical steps in HLB management and control. At the Citrus Research and Education Center, Lake Alfred, we are working on multiple approaches to develop an effective and accurate mobile sensor system that can be used to detect HLB under field conditions. This research presents some of our ongoing work on HLB detection. A SVC HR-1024 spectroradiometer (350–2,500 nm) and a portable InfraSpec VFA-IR spectrometer (5,150–10,720 nm) were used to collect data from the healthy and HLB-infected citrus leaves to evaluate the applicability of the optical sensors. The reflectance data were collected in the visible, near-infrared, and mid-infrared regions of the electromagnetic spectra. The reflectance data were analyzed using statistical methods to classify HLB-infected citrus leaves from that of healthy ones. Preliminary results showed the potential of these methods in detecting HLB-infected citrus leaves with good accuracy.

Growing and Marketing Pole Beans at Local Green Markets in Southeast Florida
Kenneth D. Shuler and Pei-Ann N. Shuler
Page 124-127
The growers for Stephen’s Produce grew and marketed pole beans (Phaseolus vulgaris L. var. vulgaris) from 2004 to 2009 to help supply local green markets with a weekend supply of “garden fresh” produce. ‘Fortex’, a French gourmet cultivar, was grown. The beans were trellised on bamboo stakes that were supported by utility wire; the wire also supported snow peas (Pisum sativum var. macrocarpon Ser.). In 2007–08 twenty plantings were made from 27 Aug. to 29 Jan. Pole beans were sold on 25 weekends from 10 Nov. to 26 Apr. The beans were sold in gallon-sized plastic storage bags at $3.00–$3.50 per pound. In 2007–08, an average of 9 lb were sold each week for an average of $31.60 per week.

A Survey of the Effectiveness of Current Methods Used for the Freeze Protection of Vegetables in South Florida
M. Ozores-Hampton, G. McAvoy, M. Lamberts, and D. Sui
Page 128-133
Florida ranks second nationally in fresh market vegetable production with 192,600 acres planted with a value of $1.4 billion in 2008–09. Seventy percent are grown in southern Florida with a harvest season from October to June during which growers may have to deal with hurricanes, droughts, and extremes in temperature. The objective of this survey was to document the effectiveness of current freeze protection methods for vegetables grown in southern Florida. During the 2009–10 season, freezing temperatures were recorded on 11 to 13 Jan. in Collier, on 10 and 11 Jan. in Miami-Dade, and on 13 Jan. 2010 in Palm Beach County. Adding to the problems caused by the freeze(s), the season was atypically cold, which slowed or precluded recovery of many crops. Losses and damage crops (acres/year) included: 0 to 35% and 0 to 100% (Southwest Florida), 60% to 90% and 5% to 10% (Miami-Dade) and 0 to 30% and 24% to 70% (Palm Beach County), respectively. The most common method of freeze protection was elevated water tables. In all counties, there was limited use of row cover/hoops, Styrofoam cups, compost, soil and hay cover, tissue paper, chemical treatments, solid set irrigation, helicopter flights and hill cultivation. The effectiveness of current freeze control methods provided poor to fair protection in Southwest Florida and Miami-Dade, but fair to good protection in Palm Beach County.

Estimating Financial Losses to Vegetable Producers and Farmworkers from a Freeze Event
Fritz M. Roka, Monica Ozores-Hampton, and Gene McAvoy
Page 134-137
The peak of southwest Florida’s vegetable growing season is from November to January. During that same period, vegetable growers face their greatest risks from cold temperatures and freezes. During early Jan. 2010, the region suffered a sustain period of cold weather with a major freeze occurring on 11 Jan. 2010. The freeze adversely affected more than 70 percent of the planted vegetable acreage. Financial losses were felt not only by growers and farmworkers, but also by the general, non-farming community. The objective of this study was to outline a methodology by which to estimate financial losses to growers, farmworkers, and the general public. Based on the methodology developed in this study, it was estimated that the 2010 freeze event created more than $197 million in financial losses. Grower losses accounted for more than 70%. Farmworkers lost nearly $36 million. The non-farm sector of southwest Florida incurred $89 million of lost economic activity. Efficient and accurate means of estimating financial losses from a freeze or other extreme weather event could assist public officials to apply for emergency aid and organize relief efforts for those most adversely affected.

Performance of Specialty Muskmelon Cultivars in High Tunnels and Open Fields
Teresa P. Salame, Bielinski M. Santos, and Daniel J. Cantliffe
Page 138-140
This study was conducted to compare the performance of three specialty muskmelon cultivars under two production systems. The cultivars were ‘Lorio’, ‘Atello’, and ‘Velsat’, whereas the production systems were open field and high-tunnel culture. The muskmelons were harvested eight times during the season and fruit were counted and weighed. On the same day, total soluble soil contents were measured from five marketable fruit per experimental unit. The results indicated that there were significant effects of each of the main factors, but not of the interaction between them on the collected variables. Marketable fruit numbers were the highest in plots planted with ‘Velsat’, whereas there was no difference in fruit number between plots inside and outside the high tunnels. Marketable fruit weight increased by 12% when grown inside high tunnels in comparison with fruit produced in open fields, and ‘Lorio’ and ‘Velsat’ had the heaviest fruit. In contrast, ‘Atello’ had the highest soluble solid content (14 °Brix), while fruit produced inside high tunnels were sweeter (14 °Brix) than those obtained in open-field plots (11.5 °Brix).

Postharvest Qualities and Nutrient Content of Vegetable
Crops Grown with or without Compost
Nancy E. Roe and Mark A. Ritenour

Page 141-146

There have been few studies of the effects of compost on the postharvest quality and quality retention of vegetables. In this study, we grew tomato (Lycopersicon esculentum Mill.), pepper (Capsicum annuum L.), and cucumber (Cucumis sativus L.) fruit, and lettuce (Lactuca sativa) leaves with or without compost and determined tomato, pepper, and cucumber fruit and lettuce leaf nutrient uptake and tested the quality of their fruit before and after storage. The experiments were conducted over two seasons in southeastern Florida on raised beds with polyethylene mulch, drip irrigation, and fertigation. Treatments were no-compost, single-year compost, and multi-year compost. Horse manure compost was applied at 10 wet tons per acre the first season and 19 wet tons per acre the second season. Tomato fruit
Ca was different only in the first season, P was different in both seasons, and K was different in the second season with similar trends in the first season. In the first season, Ca in the pepper fruit was higher from plants in the no-compost plots, Mn was lower in fruit from the multi-year compost plots, and Cu was lower in fruit from plants in the singleyear compost plots than the from plants in the other two treatments. In the second season, Mn was again lower in plants from compost plots, as was Zn. There were no differences in cucumber fruit nutrients during the first season, and in the second season only P was higher in plants from the multi-year compost treatment. During the first season, lettuce leaf Ca was higher in plants from the multi-year compost plots than in plants from the single-year compost and
no-compost plots, with no differences during the second season. The growth of these crops with and without compost resulted in few differences in postharvest storage quality in any of the crops and no clear trends.

Growing and Marketing Eggplant at Local Green Markets in Southeast Florida
Kenneth D. Shuler, Pei-Ann N. Shuler, and Stephen J. Nie
Page 147-150
The growers for Stephen’s Produce began growing and marketing eggplant (Solanum melongena L.) in 2001 to help supply local green markets with a weekend supply of “garden fresh” produce. A Sicilian type of eggplant obtained from a local grower was grown from 2001 to 2004 and ‘Rosa Bianca’, an Italian heirloom cultivar, was grown from 2005 to 2010. In 2008-09 three plantings were made with transplants set out on 14 Aug., 24 Sept., and 19 Nov. Eggplant was sold at all of the 28 weekends for the sales season, which began 20 Oct. and concluded 26 Apr. Eggplant was usually grown on beds covered with polyethylene mulch. Eggplants were sold for $1.00 to 3.00 per fruit and, in 2008–09, an average of 26 eggplants were sold each week for an average of $36 per week.

Organically Approved and Reduced Risk Pest Control Options for Fruiting Vegetable Production
Henry Brett Highland
Page 151-155
Field trials were conducted with pesticides approved (some very recently) by the United States Department of Agriculture for certified organic production in the United States for fruiting vegetables. The list includes copper octanoate (Cueva), clarified neem oil (Trilogy), Gliocladium virens (SoilGard), Paecilomyces lilacinus (Melocon), potassium salts of fatty acids (Des-X), Bacillus thuringiensis (Agree, Javelin, Deliver), and the nuclear polyhegrosis virus of Helicoverpa (Gemstar). Results from field trials have shown good activity controlling the common parasitic nematode, disease, insect, and mite pests encountered in Florida production systems using these products and following label directions.

Incidence and Spread of Strawberry necrotic shock virus (SNSV) on Strawberries in Florida
Catalina Moyer, Vance M. Whitaker, and Natalia A. Peres
Page 156-159
Strawberry necrotic shock virus (SNSV), formerly considered as a strain of Tobacco streak virus (TSV), is one of the many viruses reported in strawberries. Viral diseases have not been an issue thus far for strawberries grown in Florida, probably because most viruses are symptomless on commercial cultivars. However, at the end of the 2008–09 strawberry season, serological tests confirmed the presence of SNSV in research fields at the University of Florida Gulf Coast Research and Education Center (UF-GCREC) and in some commercial strawberry farms. The presence of SNSV was investigated during the 2009–10 strawberry season. Seven cultivars from 11 nursery sources were tested for SNSV by enzyme-linked immunosorbent assay. Leaf samples were collected three times during the season from research plots at the UF-GCREC and from a grower’s field in the Plant City area. The first sample was taken at the beginning of the season to determine if plants came infected from the nursery. In both fields, SNSV was identified on ‘Florida Radiance’ originating from nine nurseries. ‘Florida Elyana’ was also virus-positive in the UF-GCREC research plots. To determine if the virus was spreading throughout the fields, second and third samples were collected at the middle and end of the season. SNSV was detected on ‘Strawberry Festival’ at the end of the season and additional plants of ‘Florida Radiance’ were also virus-positive, suggesting that the virus had spread somewhat within the fields. During the 2009–10 season, temperatures were unusually low, which may have prevented a more rapid and extensive spread of SNSV.

Bacterial Spot Resistant Pepper Trials in Florida
Gene McAvoy, David Sui, Richard Raid, and Monica Ozores-Ham pton
Page 160-164
Cultivars and experimental hybrids of bell peppers (Capsicum annuum L.) were transplanted in commercial pepper fields during the 2009–10 growing seasons in two locations in South Florida. The objectives of the study were to evaluate horticultural characteristics and resistance to bacterial spot of peppers caused by Xanthomonas euvesicatoria (formally Xanthomonas axonopodis pv. vesicatoria and Xanthomonas campestris pv. vesicatoria). Cultivars tested included standard commercial varieties with race 1, 2, 3 bacterial spot resistance and newer cultivars and lines that incorporated additional resistance to bacterial spot races 4, 5 and 6. Both studies were conducted in commercial pepper fields containing naturally occurring levels of X. euvesicatoria inoculum. In these trials, it was demonstrated that cultivars containing the added resistance to race 4, 5 and/or 6 significantly reducing bacterial spot infection rates and increased yields compared with varieties with only resistance to bacterial spot races 1, 2 and 3.

Evaluation of Herbicides for Management of Weeds in Sweet Basil (Ocimum basilicum)
David D. Sui, William M. Stall, Richard N. Raid, and Eugene McAvoy
Page 165-168
Sweet basil (Ocimum basilicum L.) is one of the world’s most popular herbs, with much of the U.S. fresh market basil being produced in Florida. In the field, weed control is a continual problem. With few registered herbicides, growers must rely on mechanical control or hand-weeding, which are frequently ineffective and/or expensive. During 2009, trials were initiated to select potential candidates for chemical control. On a commercial sand soil site during spring, eight herbicides were screened for crop tolerance and weed control. Candidates included linuron, S-metalochlor, napropamide, halosulfuron, and dimethenamid applied preemergence, and linuron, halosulfuron, and clopyralid applied postemergence. Of the preemergence treatments, all provided good weed control but linuron, dimethenamid, and metalochlor resulted in crop death at the rates tested. Napropamide (2.0 lb ai/acre) resulted in the highest crop vigor, followed by halosulfuron (0.375 oz ai/acre). Of the postemergence treatments, all gave some measure of weed control, with clopyralid producing the least crop damage, followed by halosulfuron, and then linuron. In a trial conducted on an organic soil site during winter, linuron was tested at three different rates preemergence, followed by linuron, imazethapyr, and prometryn, each at three different rates postemergence. Linuron as a preemergence treatment on muck provided significant weed control and acceptable crop vigor at all three rates tested (0.125, 0.25, and 0.375 lb ai/acre). Of the postemergence treatments, only linuron at 0.1 ai/acre provided significant weed control with minimal reductions in crop vigor. Prometryn resulted in crop death and imazethapyr significantly reduced crop vigor at the rates tested.

Searching for an Ideal Soil Extractant for Determining Sulfur in Sandy Soils
C.E. Esmel, B.M. Santos, J.E. Rec hcigl, G. Toor, E.H. Simonne, and J.W. Noling
Page 169-174
Soil testing could provide useful information for developing fertilizer programs for S fertilization. No reliable correlation has been found between soil extractable S or SO4-S and plant yield. The S fertilizer recommendations were not soil test based and relied upon leaf analysis results. The objectives of this study were to 1) compare soil extractants for SO4-S over selected soil samples and 2) compare these SO4-S values to total S in plant tissues and tomato (Solanum lycopersicum L.) yield. Fifty-two paired soil from Spodosols and tomato leaf samples were collected for total S and SO4-S determination. Soil extracting solutions used were Mehlich-3, de-ionized water, and 0.025 M KCl. Linear regression analysis and slope comparison against an ideal linear regression line were used. Relationships between various soil extraction solutions and plant tissue S or tomato yield were found to be variable with low R2 values (<0.70). These results suggest that the predictability of any soil extractant with tomato plant tissue S or yield was low, thereby rendering a soil test based on these extractions unpractical. Hence, the current Florida recommendation for S using plant analysis should continue to be utilized.

Movement of the Wetted Front under Drip-irrigated Tomatoes Grown on a Sandy Soil
Bee Ling Poh, Apaparna Gazula, Eric H. Simonne, Robert C. Hochmuth, and Michael R. Alligood
Page 175-178
Keeping water and nutrients within the rootzone of vegetable crops is the main goal of nutrient Best Management Practices. Because the actual depth of water movement below a crop depends on the volume of water applied and how much water is taken up by the plant, it is possible that reducing drip irrigation system operating pressure (OP) as a means to increase the length of irrigation time may result in slower vertical water movement due to 1) greater lateral water movement and 2) increased plant water uptake. Without a crop, water moved in a deep sandy soil at rate of 0.057 to 0.17 mm/L/100 m (0.3 to 0.9 inch/10 gal/100 ft). Assuming a typical daily irrigation schedule of 2 h using a flow rate of 300 L/100 m/h (24 gal/100 ft/h), the estimated wetted soil depth would be 216 to 650 cm (86 to 260 inches) after 60 d. In this study, tomato plants were grown for two seasons using plasticulture. Treatments were OP of 41 and 82 kPa (6 and 12 psi) and two irrigation rates of 100% and 75% of the UF-IFAS recommended rate. Blue dye was injected on 14 and 21 DAT and the soil was dug on 80 and 84 DAT in 2008 and 2009, respectively. The depth of waterfront was significantly affected by OP (P = 0.01) with maximum average wetted depths of 130 and 158 cm (52 and 63 inches) at 42 kPa (6 psi), and 160 and 168 cm (64 and 67 inches) at 84 kPa (12 psi), respectively, for 2008 and 2009. Surprisingly, irrigation rate effect was not significant on the depth of waterfront at 145 and 165 cm (58 and 66 inches) at 100% IRR and 143 and 163 cm (57 and 65 inches) at 75% IRR in 2008 and 2009, respectively. While reducing OP significantly reduced the downwards movement of water in the soil, it was not sufficient to keep the irrigated water from moving beyond the crop rootzone on a sandy soil. Hence, reduced OP should not be relied upon as a panacea, but should be used together with other nutrient BMPs.

Novaluron for Control of Larval Sap Beetles in Strawberries
James F. Price and Curtis A. Nagle
Page 179-182
Strawberries (Fragaria ×ananassa Duchesne) valued at about $314 million were produced on 8,800 acres in Florida during 2009. Episodes of sap beetles (Nitidulidae, principally Lobiopa insularis and Haptoncus luteolus) entering fields in late winter, chewing holes in ripe fruit and reproducing there occur annually in most fields. The presence of small numbers of adults or their larvae in fresh fruit inflicts significant economic damage. Pesticides presently available for control have been inadequate and growers have relied largely on field sanitation, including removal of all ripe fruit regardless of sales value, to reduce losses. Those costly measures sometimes result in unacceptable sap beetle presence. Experiments were conducted in both 2009 and 2010 to determine the usefulness of aqueous sprays of novaluron, the benzoylurea inhibitor of chitin biosynthesis insecticide (an insect growth regulator), for management of sap beetle larvae. Results indicate that novaluron insecticide applied at 36 fluid ounces per acre per season in various spray concentrations and intervals in the late season provided excellent control of larvae.

Effect of Added Elemental Sulfur on Soil pH and Phosphorus Availability in Sandy Soils
Kelly T. Morgan, Shinjiro Sato, and Eugene McAvoy
Page 183-186
Phosphorus precipitates out of soil solution and becomes unavailable for plant uptake as soil pH and Ca content increases. The reduced P plant availability in soils with pH >7.0 and Ca concentrations >1000 mg·L–1 renders soil tests using Mehlich 1 extractant ineffective because the acids that make up this extractant can dissolve precipitated P and reflect soil P concentrations not available to plants. The effect of lowering soil pH with S to increase plant availability of fertilizer P is of interest to growers, environmentalists, regulators, and the general public because of improved P availability to crop plants and possible impact of increased S concentrations on the environment. The objective of this field study was to determine the length of time soil pH was reduced by application of S in polyethylene-mulched beds and the subsequent affect on growth and productivity of tomato (Solanum lycopersicum L.). Sulfur was applied to two selected fields at two rates in combination with four P rates. It was determined that the soil pH reduction from the initial S applications rates equivalent to 280 and 560 kg of S per hectare applied only in the planted row lasted less than 60 days and had minimum effect on P availability during the entire crop growing season.

Improving Irrigation Management for Strawberry Establishment in West-central Florida
Bielinski M. Santos, Teresa P. Salame-Donoso, Alicia J. Whidden, and Maricruz Ramírez-Sánchez
Page 187-188
A study was conducted to assess the use of kaolin clay-based crop protectants in combination with sprinkler irrigation for strawberry (Fragaria ×ananassa) transplant establishment. Bare-root strawberry transplants were set in fumigated, raised beds covered with polyethylene mulch. Seven treatments resulted from the combination of duration of sprinkler irrigation (8 h/day) and foliar application of kaolin clay: 4 d of sprinkler irrigation; 4 d of sprinkler irrigation plus kaolin clay on day 5; 6 d of sprinkler irrigation; 6 d of sprinkler irrigation plus kaolin clay on day 7; 8 d of sprinkler irrigation; 8 d of sprinkler irrigation plus kaolin clay on day 9; and 10 d of sprinkler irrigation (control). The results indicated that there were no significant differences in plant establishment and early fruit weight of strawberry between plants that were established with the application of 10 d of sprinkler irrigation and either 6 or 8 d of sprinkler irrigation plus foliar-applied kaolin clay. With the use of foliar-applied kaolin clay, water savings were between 3.7 and 5.6 acre-inch/acre of water, which might have a major impact on water management for strawberry production in west-central Florida.

Evaluation of Methodologies to Estimate Reference Evapotranspiration in Florida
E.M. Gelcer, C.W. Fraisse, and P.C. Sentelhas
Page 189-195
The Penman-Monteith equation was considered by the United Nations Food and Agriculture Organization (FAO) as the standard method to calculate reference evapotranspiration (ETo). The lack of data availability, especially in long-term historical records, was the basic obstacle for a broader use of the FAO Penman-Monteith equation. Long-term records often included daily maximum and minimum temperatures and precipitation. In these circumstances empirical methods could be used but required calibration for local conditions and were not readily transferable to other regions. The main objectives of this study were to compare reference evapotranspiration estimated by the FAO Penman-Monteith equation to reference evapotranspiration estimated by the Priestley and Taylor and the Hargreaves empirical methods. The use of the FAO Penman-Monteith equation with estimated solar radiation, relative humidity, and wind speed was also evaluated. Daily, 10-d, and monthly values of reference evapotranspiration calculated by Penman-Monteith and the other methods were compared. The Priestley and Taylor method was found to be the best method to use when available long-term historical records included only daily temperature and precipitation. This methodology can be used in climatological studies for irrigation planning and to better understand the effects of seasonal climate variability on crop water requirements in Florida.

Nutrient Management Programs for Fresh Market Tomatoes Grown with Plasticulture: Economic Insights
Aparna Gazula, Eric H. Simonne, and Fritz Roka
Page 196-198
Fertilizer represents only a small portion of the total costs to grow fresh market tomatoes (Solanum lycopersicum L.). Therefore, growers may apply fertilizer rates in excess of UF/IFAS recommendations to prevent nutrient shortages and maintain productivity. With the adoption of BMPs to implement the TMDLs, growers are encouraged to follow UF/IFAS nutrient-irrigation recommendations. The objectives of this study were to 1) estimate the costs of UF/IFAS nutrient-irrigation management practices; 2) estimate total production costs with the UF/IFAS recommendations; and 3) calculate break-even prices. The estimated cost of UF/IFAS recommended nutrient-irrigation practices was $803.87/acre. Based on an estimated marketable yield of 1,500 25-lb tomato cartons/acre, the estimated production cost with UF/IFAS recommendations was $11,667.96/acre, and the break-even price for a 25-lb tomato carton was $7.78. The irrigation-fertilizer costs represented 4.41% and 2.48% of the total production costs, respectively. Upon doubling them, the fertilizer inputs represented an estimated 4.84% of the total production costs, and the break-even price increased by 19 cents to $7.97. Average prices of ‘U.S. One or Better’ grade tomatoes from 1998–2008 ranged between $7.88 and $14.76/25-lb carton, and the growers would have realized profits for 9 and 8 years with the UF/IFAS, and the growers’ high fertilizer input practices, respectively.

A Comparison of Processed and Fresh Squeezed ‘Hamlin’ Orange Juice—Flavor Quality
Jinhe Bai, Elizabeth Baldwin*, Anne Plotto, Randall Cameron, Bryan L. Ford, Gary Luzio, John Manthey, Jan Narc iso, and Sharon Dea
Page 199-206
‘Hamlin’ orange juice was extracted using a commercial food service juicer (“fresh squeezed”) followed or not with pasteurization and compared to pasteurized processed juice for quality attributes. There was much higher peel oil content (introduced from the flavedo), but lower insoluble solids and pectin content (introduced from albedo and segment membranes) in fresh squeezed juice compared to processed juice. Fresh-squeezed juice had less cloud loss in comparison with processed juice regardless of pasteurization. Titratable acidity (TA) was higher and the ratio of soluble solids to TA was lower in fresh squeezed juice. The fresh squeezed juices had higher concentrations of hexanal, octanal, 2-methylpropanol, hexanol, cis-3-hexenol, trans-2-hexenol, octanol, α-pinene, sabinene, myrcene, limonene, methyl butanoate and ethyl butanoate, but lower concentrations of terpinen-4-ol and α-terpineol than processed juice. There were no differences between samples for preference or sweetness in sensory evaluations. However, the fresh juice had favorable attributes indicated by the higher sensory scores for freshness, mouthfeel and a lower score of cooked flavor, an unfavorable attribute associated with processing. The results indicate that extraction and finishing processes rather than pasteurization were major factors in influencing the orange juice flavor quality.

A Comparison of Processed and Fresh Squeezed ‘Hamlin’ Orange Juice—Nutrients and Phytonutrients
Jinhe Bai, Bryan L. Ford, John A. Manthey, and Elizabeth A. Baldwin
Page 207-212
‘Hamlin’ orange juices were prepared using one of following methods: 1) freshly squeezed with a commercial food service squeezer (fresh), 2) freshly squeezed and pasteurized (fresh/pasteurized), and 3) processed with industrial extractor and pasteurized (processed). Samples were taken from the juices directly after extraction and again after 4 d of juice storage at 5 °C for analysis of flavonoids, limonoids, alkaloids, carotenoids, ascorbic acid and total phenolic content. Processed juice had higher levels of insoluble solids, but lower levels of peel oil in comparison to fresh juice regardless of pasteurization. The majority of flavonoid glycosides including hesperidin, narirutin, narirutin 4´-glucoside, 6,8-di-C-glucosyl apigenin and isosakuranetin rutinoside, which are rich in the albedo and segment membranes, occurred at the highest levels in processed juice. In contrast, the polymethoxylatedflavones associated with peel oil, such as quercetagetin hexamethyl ether, sinensetin, nobiletin, tetramethylscutellarein, heptamethoxyflavone and tangeretin occurred at the highest levels in the fresh juices. Limonoids (limonin glucoside, limonin aglycone, nomilin glucoside, nomilinic acid glucoside, and nomilin aglycone), alkaloids (feruloyl putrescine and an unknown alkaloid) and carotenoids (zeaxanthin, lutein, ß-cryptoxanthin, α-carotene and ß-carotene) occurred at higher levels in the processed juice than in the fresh juice regardless of pasteurization. The processed juice had higher total phenolic content but lower ascorbic acid content than the fresh juices. Thermal pasteurization increased the contents of the polymethoxylated flavones, but decreased the contents of carotenoids. During 4-d storage at 5 °C, 20% to 80% of hesperidin, narirutin, narirutin 4´-glucoside and isosakuranetin rutinoside precipitated in the processed juice but not the fresh juice.

Contactless Conductivity: An HPLC Method to Analyze Degree of Methylation of Pectin
Gary A. Luzio and Randall Cameron
Page 213-216
After removal of soluble sugars and other compounds by washing, citrus peel is largely composed of pectin, cellulose, and hemicelluloses. One of the major components, pectin can be modified using pectinesterases, which reduce the degree of methylation (DM). Low DM pectins have great utility in the food industry and other applications. They have been shown to have calcium sensitivity, which is an important functional property of pectins for use in applications which require suspension, metal ion binding or water absorption. Thus, an estimate of DM is an important parameter to determine but most DM analyses are difficult to perform. A new method has been developed based on contactless conductivity. The conductivity, as measured by a contactless conductivity meter, increases with decreasing DM, with values ranging from 94.0 to zero when pectins are analyzed on size exclusion chromatography columns (SEC) with concentration of pectin measured with interferometric refractive index detector (RI). Data fit to a linear equation, of DM to conductivity detector response, yields y = –5.96 × 10–3x + 0.592 with an r2 value of 0.998. These results demonstrate that DM and molecular weight can be measured simultaneously on SEC using contactless conductivity.

Salmonella Does Not Penetrate Citrus Peel through Natural Light Labels
Michelle D. Danyluk, Preeti Sood, Liss eth Proano, Loretta M. Friedrich, and Ed Etxeberria
Page 217-219
In natural light labeling of fruit and vegetables, the desired information is etched onto the produce surface using a low-energy carbon dioxide laser beam (10,600 nm). Etched characters are formed by surface depressions in the epidermis that seemingly facilitate entrance of decay and pathogenic organisms. The objective of this study was to determine the effect of natural-light labeling and different postharvest treatments on Salmonella’s ability to survive/grow and penetrate into citrus fruit. A five-strain cocktail of Salmonella was spot inoculated onto ‘Valencia’ orange peels in different application sequences with wax and laser etching. Inoculated samples were stored at 10 or 26 °C. Etched peels and corresponding juices were extracted and enumerated for Salmonella. No set of conditions promoted the growth of Salmonella on the fruit surface or allowed penetration into the juice. Survival of Salmonella populations on the peel surface did not differ between any of the treatment and control (unlabeled samples). In all cases, Salmonella declined between 1.5 and 3.0 log colony forming units (cfu)/orange after 30 d, with faster decline noted at 10 °C. Based on the data obtained from all treatments and under conditions extremely unfavorable and unrealistic in terms of fruit storage, natural light labeling citrus fruit peels and subsequent waxing in any order does not allow for the growth nor influence the natural decline of Salmonella populations on citrus fruit surfaces as compared to controls.

Improved Removal of Ascorbate Interference in the Folin-Ciocalteu Assay of “Total Phenolic Content”
Bryan L. Ford, Jinhe Bai, John Manthey, and Elizabeth A. Baldwin
Page 220-222
The venerable Folin-Ciocalteu (F-C) assay for total phenolics can have severe limitations due to interference by ascorbic acid (AsA). For common fruit juices AsA interference can substantially exceed the magnitude of the total phenolic signal. Ascorbate oxidase (AO) has been a promising approach to eliminating the AsA interference, but the oxidation product of AsA by AO is dehydroascorbic acid (DHA), which is an F-C reductant that gives an apparent signal implying a molar strength of 15% to 30% of the original AsA. Hydrogen peroxide (H2O2) was successfully used to degrade this residual DHA into products that are not F-C reductants. Using a model orange juice, the impact of this small amount of (~450 ppm) of H2O2 on the orange and non-orange phenolic measurements was examined. Chemical means were sought to quench the H2O2 oxidative activities shortly after it destroyed the DHA, or to otherwise prevent interaction with the phenolics present without altering the F-C signal. Some promising candidates were identified, but none protected the phenolics completely. The best that can be said is that conditions can be easily set so that the alteration in phenolics represents less than a 10% perturbation in the untreated model juice F-C signal. Although this is much better than the large errors originally seen from AsA (100% or more of a typical orange juice phenolic signal) or from the residual DHA (15% to 30% error), further work is needed to develop an approach to the point that it predictably causes no more than a 5% artifactual error.

Anthocyanin Identification, Vitamin C Content, and Antioxidant Capacity of Acerola (Malpighia emarginata DC) Juices
Lemâne Delva and Renée M. Goodrich
Page 223-227
The main objectives of this study were to identify and quantify anthocyanin content in acerola juices and to determine the antioxidant capacity of the juices. Anthocyanin content was analyzed by a high-performance liquid chromatograph connected to a diode array and mass spectrometry detectors (HPLC–DAD–MS/MS). The antioxidant capacity was determined by the 2,2´-diphenyl picryl hydrazyl (DPPH) and the oxygen radical absorbance capacity (ORAC) assays. The ascorbic acid content was determined by HPLC. The frozen single-strength acerola juice presented 53.60 mg total anthocyanin for 100 mL with predominance of cyanidin 3-rhamnoside as individual anthocyanin. The frozen single-strength juice showed 306.77 and 85.29 mmole Trolox equivalent for 100 mL juice respectively for DPPH and ORAC antioxidant values. The ascorbic acid (vitamin C) content was found to be 4440 mg for 100 mL single-strength juice. Anthocyanin and ascorbic acid seemed to be the major contributors of the antioxidant capacity of the juice. Overall, this study shows that acerola juice is good source of anthocyanin pigment, an outstanding source of ascorbic acid and a potential good source of antioxidant.

Daily Intake of Pasteurized Orange Juice Decreases Serum Cholesterol, Fasting Glucose, and Diastolic Blood Pressure in Adults
Lívia G. Basile, Cláudia G. Lima, and Thaïs B. César
Page 228-233
Previous studies have shown that fresh squeezed orange juice or juice from reconstituted concentrate can help prevent the development of atherosclerosis. Pasteurized orange juice presently represents the major orange juice available in the market, and because of this, it becomes necessary to determine the healthy benefits associated with this product. In this study we investigated the effect of regular consumption of pasteurized orange juice on the nutritional status, biochemical profile, and arterial blood pressure in healthy men and women. Men and women volunteered to consume pasteurized orange juice (500 mL·d–1 and 750 mL·d–1, respectively), for 8 weeks. Anthropometric, biochemical, hemodynamic, and dietary assessments were evaluated at baseline and at the end of the experimental period. Total cholesterol and LDL-C significantly decreased in both men and women after the consumption of orange juice, and an increase in HDL-C level was detected exclusively in women. Fasting glucose, diastolic blood pressure, and triglyceride levels dropped in men after the consumption of orange juice. Anthropometric variables did not change with orange juice consumption, only waist circumference decreased significantly in women. Consumption of orange juice increased the energy and carbohydrate intake for women; however, vitamin C and folate increased after the orange juice period for both men and women. Regular consumption of pasteurized orange juice by men (750 mL·d–1) and women (500 mL·d–1) reduced the risk of developing atherosclerosis, and increased the nutritional quality of their diets.

Effects of Growing Location, Storage Temperature, and Fruit Coating on Postharvest Quality and Quality Retention of ‘Sugar Belle’™ Mandarin
Sambhav, Mark A. Ritenour, Cuifeng Hu, Fred G. Gmitter, William S. Castle, and Jude W. Grosser
Page 234-237
‘Sugar Belle’™ mandarin (previously known as LB8-9) was released to Florida citrus growers in 2009. Fruit were evaluated during the 2008–09 and 2009–10 seasons in terms of growing location and response to different postharvest coatings and storage temperatures to further refine their optimum postharvest handling practices. Fruit were obtained from blocks in Orange or Indian River (IR) Counties, washed and coated with either shellac or carnauba wax, and then stored at 1, 4, or 10 °C for up to 39 d and then transferred to ambient temperatures for an additional 7 d. In general, fruit from the Orange County block developed less postharvest decay and peel breakdown than fruit from the IR County block. Uncoated fruit or fruit stored at warmer temperatures developed better external color during storage. Use of coatings, especially carnauba, or storage at cooler temperatures inhibited fruit water loss most. Except for fruit from the IR block during the first season, the development of decay and physiological disorders during storage and subsequent transfer to ambient conditions was inhibited significantly more if stored at 1 or 4 °C than at 10 °C. Fruit from the IR block developed what appeared to be chilling injury (CI) when stored at 1 or 4 °C during the first season only. It is not clear if this different response is due to growing location, age of the block, or some other unknown factor. When CI developed, coating the fruit with either shellac or carnauba wax reduced the development of the symptoms. ‘Sugar Belle’ mandarins were also found to have a positive, exponential relationship between fruit size and internal seed content.

Polygalacturonase Activity Does Not Fully Explain Textural Differences of Melting Flesh versus Non-melting Flesh Peaches
Ming-Wei S. Kao, Jeffrey K. Brecht, and Donald J. Huber
Page 238-240
Texture is the main distinction between melting-flesh (MF) and non-melting flesh (NMF) peach cultivars. MF peaches soften extensively toward the end of the ripening process while NMF peaches soften more slowly and lack the “melting” stage of fruit softening. Two pectolytic enzymes thought to be involved in peach softening are terminal cleaving exo-polygalacturonase (exo-PG) and random cleavingendo-PG. The decreased capacity of NMF peaches to degrade cell walls (i.e., soften) is thought to be related to a deletion of endo-PG gene or a truncation of the mRNA. Thus, NMF cultivars would be expected to possess lower endo-PG activity than MF cultivars. In this study, the extractable PG activity of two MF cultivars, ‘Flordaprince’ and ‘TropicBeauty’, and two NMF cultivars, ‘UFSun’ and ‘Gulfking’, during the climacteric ripening stage were determined. ‘Flordaprince’ possessed similar endo- and exo-PG activities as the two NMF cultivars while ‘TropicBeauty’ had the highest endo- and exo-PG activities of the four cultivars. Surprisingly, the endo-PG activity of NMF ‘Gulfking’ was significantly higher than its exo-PG activity and was also higher than that of MF ‘Flordaprince’. However, the higher endo-PG activity of ‘Gulfking’ was not reflected in its texture since it was almost five times firmer when ripe than ‘Flordaprince’(10.77 N vs. 2.34 N), which implies that endo-PG activity does not fully explain the textural differences between MF and NMF peaches. Since cell wall disassembly presumably involves concerted and synergistic action of several different enzymes, other cell wall modifying enzymes may have a more crucial role than PG during peach fruit softening.

Evaluation of Roma Tomato (Solanum lycopersicum) Peeling Methods: Conventional vs. Power Ultrasound
Cheryl Rock, Wade Yang, Jyotsna Nooji, Arthur Teixeira, and Hao Feng
Page 241-245
Tomatoes are mainly consumed in processed form, which often requires peeling prior to processing. Conventional methods of peeling tomatoes includes the use of lye at considerably high concentration (10% to 15%), which generates increasing concerns on its disposal and environmental impacts, as well as material costs. In addition, lye has resulted in high peeling losses that adversely affected the yield of product. In this study, a comprehensive evaluation of peeling methods: lye (2% or 10%), power ultrasound, and lye (2%) in combination with power ultrasound were conducted. Peeling performances were evaluated based on ease of peeling and peeling losses of tomatoes after treatments. Results showed that peeling with power ultrasound in hot water yielded better ease of peeling score and much lower peeling losses than conventional lye peeling (P < 0.05). Peeling with much reduced lye concentration (2%) generated statistically (P < 0.05) comparable ease of peeling scores to the conventional 10% lye. Tomatoes treated with low concentration lye (2%) in combination with power ultrasound resulted in significantly ((P < 0.05) lower peeling losses compared to 2% or 10% lye. It was also found that further increase of exposure time to 75 s did not significantly ((P < 0.05) improve ease of peeling scores. Our findings suggest that ultrasonic power strength, not duration, was key to effective peeling and that 2% lye might be as effective as 10% for lye peeling.

Survival of Salmonella spp. on Lime Slices
Rachel McEgan and Michelle D. Danyluk
Page 246-247
Lime slices are commonly added to beverages in the food service industry; little is known about microbial risks associated with this practice. The objective of this study was to determine survival of Salmonella spp. on lime slices stored on ice for 8 h then transferred to 4 °C or at room temperature. A five-strain cocktail of Salmonella [5 log colony-forming units (cfu) per slice)] was spot inoculated onto the flesh, flavedo, or albedo of sliced limes and held on ice or at room temperature for up to 24 h. Salmonella were enumerated by plating on selective agar during the 24-h storage. Salmonella inoculated onto the albedo and held at room temperature first decreased by 1 log cfu/slice within the first hour then grew back to 6 log cfu/slice. When inoculated onto either the flesh or flavedo and held at room temperature no significant difference was observed in the counts of Salmonella over the 24-h period; counts remained at ≈5 log cfu/slice. When stored on ice the initial Salmonella load (at time 0 h) was ca. 4.5 log cfu/slice and remained with no significant difference over the 24-h storage time. The demonstrated ability of Salmonella to survive on lime slices suggests a potential food safety risk associated with improperly handled sliced limes.

Fractionation of Secondary Metabolites of Orange (Citrus sinensis L.) Leaves by Fast Centrifugal Partition Chromatography
John A. Manthey
Page 248-251
Conventional high-pressure liquid chromatography (HPLC) provides ready detection of the major phenolic compounds in methanol extracts of orange leaves, yet conventional HPLC also shows the presence of many more compounds, to an extent where extensive peak overlap prevents distinct peak detection and reliable quantitation. A more complete chromatographic analysis of the complex compound profiles of orange (Citrus sinensis) leaves was made possible with separations by fast centrifugal partition chromatography (FCPC) prior to HPLC analysis. Separations by FCPC were achieved using the biphasic system of ethanol/butanol/water (20/80/100, v/v/v). Early eluted fractions contained numerous polar and mid-polar hydroxycinnamates. Later eluting fractions contained various profiles of polar and mid-polar flavonoids, many of which significantly overlapped in the HPLC of the original orange leaf extract. Analysis of the FCPC fractions by HPLC-time-of-flight mass spectrometry provided detection of many more compounds compared to other conventional methods of detection used with HPLC.

Preharvest Measures for Postharvest Improvement in Marketable Fresh Citrus
J. Narciso, C. Ference, and W. Peeples
Page 252-254
Citrus canker caused by the bacterium Xanthomonas citri subsp. citri (Xcc), was once the scourge of the Florida citrus industry from the early 1900s on and off until the early 1990s. It has been replaced in importance, for the most part, by citrus greening but still continues to be a problem for Florida fresh citrus. The most recent canker outbreak peaked soon after the 2004 hurricanes, where the rains and winds spread the disease more quickly than it could be controlled. Although some of the strict quarantines placed on the citrus industry at the beginning of the latest canker epidemic have been lifted, there is still a problem with shipping fruit from cankered areas out of the country. Although work is continuing on postharvest measures to ensure that no live canker bacteria leave the packing houses, preharvest measures are also being improved to decrease the disease pressure in the groves as well as to lower incidence of infection on the fruit. Most commonly, a copper formulation is sprayed on the trees soon after petal fall for control of canker. Copper has long been used as an effective fungicide because fungi are sensitive to metals. However, the sprayed copper tends to be powdery and a good deal of it is removed from the leaves and fruit when it rains. Rain and wind are the chief means of carrying the canker bacteria from diseased to healthy plants and curtail the efficiency of copper applications. In 2009 copper and carnauba wax as “a sticking agent” were mixed and this formulation was used to spray experimental trees in a commercial grove. At the end of the growing season there was a significant reduction in canker lesions on the fruit as well as a dramatic reduction in melanose. With the emergence of yet two more fungal diseases on citrus (citrus black spot, Guignardia citricarpa Kiely; and sweet orange scab, Elsinoe australis Bitancourt& Jenk.), the increased exposure of these citrus pests to a pesticide that is maintained and protects the plant surfaces during times of great disease pressure will facilitate the harvest of more unblemished and marketable fruit.

Commercial Postharvest Practices Used to Handle Fresh Citrus Fruit with Canker Symptoms
Mark A. Ritenour, Lucimeire Pilon, Ron Muraro, Jan Narciso, and Thomas F. Burks
Page 255-258
To assist in developing best postharvest practices for handling fruit with canker lesions, a survey was distributed in summers of 2008 and 2009 to better understand current practices. Approximately 60% of the surveys were returned each year, representing about 55% of total fresh fruit shipments. As expected, the percentage of fruit received from blocks certified canker free declined from 2008 to 2009 as canker spread within the state. Sodium o-phenylphenate was the fruit disinfestation sanitizer most used by 52% of the packers to decontaminate fruit in 2008, but its use declined to 47% in 2009. Use of peroxyacetic acid increased from 21% to 33% over the same period, while chlorine use dropped from 27% to 20%. Most (~50%) of the sanitizers were applied as the fruit were first wetted, but managers were switching more to applying as the fruit were washed or afterwards. For both years, an average of 22 human graders were stationed at different points on the packingline to evaluate each load, with most (83%) increasing to 27 graders when fruit was known to come from a block with canker infection. All but one respondent reported that electronic graders were not useful for removing fruit with canker symptoms. In 2009, packers estimated that 34% of the citrus crop normally packed for the European Union market was disqualified because of canker and that 12% of the product packed for the domestic or Japanese markets was either disqualified, or contained sufficient canker infection to make unprofitable to pack for the fresh market.

Electronic Nose for Detecting Strawberry Fruit Maturity
Xiaofen Du, Jinhe Bai, Anne Plotto, Elizabeth Baldwin, Vance Whitaker, and Russell Rouseff
Page 259-263
An electronic nose (e-nose) composed of 18 different metal oxide gas sensors was used to characterize the volatile patterns of ‘Strawberry Festival’ and ‘Florida Radiance’ strawberry fruit at five developmental stages: white, half red, three-quarter red, full ripe, and overripe. Strawberry samples were harvested at three harvest dates from early February to the end of March. Three-gram aliquots of strawberry puree were employed for headspace sampling in 10-mL vials, which were incubated at 40 °C for 2 min prior to analysis. Volatiles from each sample were sampled for 2 min with data acquisition every second. After analysis, there was an 18-min delay for sensor recovery. E-nose sensor data was reproducible with 90% of sensor responses having relative standard deviations of less than 10%. Sensors P30/1, T30/1, and P30/2 were the major differentiating sensors for strawberry maturity as indicated by their loadings on the first principal component (PC1). Immature and less mature fruit were well separated from full ripe and overripe fruit on PC1, regardless of cultivar. Harvest date was separated primarily by the second principal component. E-nose volatile patterns of ‘Strawberry Festival’ and ‘Florida Radiance’ strawberry cultivars were separated at identical stages of development. E-nose technology has the potential to monitor strawberry maturity and fruit quality.

Effect of Postharvest Application of 1-MCP on Basil Shoot Quality during Storage at Chilling Temperature
Adrian D. Berry, Steven A. Sargent, and Donald J. Huber
Page 264-268
Basil (Ocimum basilicum) is one of the most temperature-sensitive of the fresh herbs, developing chilling injury symptoms within a few days of exposure to less than 12 °C, a common occurrence during commercial handling. The objective of this study was to evaluate the potential of increasing the tolerance of cut, basil shoots (‘Nufar’) to storage temperatures at 5 or 10 °C by postharvest immersion in an aqueous form of 1-methylcyclopropene (1-MCP), an ethylene-action inhibitor. Shoots were either left dry, dipped in deionized water or dipped in a 1-MCP solution of 500 μg·L–1 for 30 s. Dipped shoots were air-dried prior to packing in commercial, plastic clamshell containers and stored at 5 or 10 °C for 12 d. Shoots from all treatments retained good to excellent quality when stored up to 9 d at 5 or 10 °C. However, regardless of treatment, after 12 d at 5 °C basil shoots had significant necrosis due to chilling injury and were therefore unmarketable. Basil stored at 10 °C remained marketable during the 12-d storage period, but once transferred to 20 °C quality was significantly reduced. After 12 d at 5 or 10 °C there was no significant difference between treatments for the parameters tested. The following parameters were determined after 12 d at 5 and 10 °C, respectively: leaf hue angle was 121.7° and 119.8°; total chlorophyll content was 1.2 and 1.18 mg·g–1 fresh weight; moisture content was 89.32 and 89.58 %. These results showed that dipping basil shoots in a 1-MCP solution of 500 μg·L–1 did not reduce susceptibility to chilling injury during storage at 5 °C.

Potential of 1-Methylcyclopropene to Delay Ripening and Extend Quality of Avocado Fruit during Refrigerated Storage
Steven A. Sargent, Adrian D. Berry, Marcio E.C. Pereira, and Donald J. Huber
Page 269-273
This study was conducted to evaluate the effects of aqueous 1-methylcyclopropene (1-MCP) formulation on ripening and quality of avocado (Persea americana Mill., ‘Monroe’) fruit under simulated commercial conditions. Twenty-four hours after harvest in Homestead, FL, mature-green fruit were either immersed in aqueous 1-MCP at 75 μg·L–1 (75 ppb a.i.; 20 °C) or deionized water for 1 min. All fruit were stored at 10 °C for 14 d, then transferred to 20 °C until ripe (15 N firmness). Respiration, ethylene production, softening, and surface hue angle were delayed and/or suppressed in fruit exposed to 1-MCP. Ethylene production was delayed approximately 3 d and fruit ripening up to 6 d, compared to control fruit. Avocado fruit treated with 1-MCP maintained equal or better visual quality during ripening as compared to control fruit.

Maturity and Postharvest Performance of ‘US Early Pride’ Seedless Mandarins
T. Gregory McCollum, C.J. Hearn, and Mark Ritenour
Page 274-277
‘US Early Pride’ is an early season, seedless mandarin developed and recently released by the USDA, ARS. ‘US Early Pride’ resulted from irradiated budwood of ‘Fallglo’ mandarin in 1991. Trees were produced from the irradiated budwood and planted into the field in 1992. In 1995 a seedless mutant (USDA 1-62-122) was identified and subsequently propagated on multiple rootstocks for evaluation. Based upon horticultural performance of the USDA 1-62-122 trees and fruit quality characteristics, especially the absence of seeds, USDA 1-62-122 was released in 2009 as ‘US Early Pride’. Although ‘US Early Pride’ has been found to be essentially identical to ‘Fallglo’ with the exception of being seedless, detailed studies to document time of maturity and postharvest behavior had not been conducted prior to release. We harvested ‘US Early Pride’ and ‘Fallglo’ fruit at intervals from October through late November and standard fruit quality parameters (size, weight, rind color, total soluble solids, (Brix) and titratable acidity) were quantified for both scions. Data indicate that ‘US Early Pride’ fruit are slightly smaller than ‘Fallglo’. ‘US Early Pride’ and ‘Fallglo’ fruit were both legally mature in early October and maintained acceptable quality on the tree at least until late November. Following harvest, the response to ethylene was similar in ‘US Early Pride’ and ‘Fallglo’. Sugars and acids were fairly consistent in the two cultivars during storage at 10 °C for 3 weeks. Decay and other postharvest disorders did not develop in either cultivar during storage. Our results document that ‘US Early Pride’ is equivalent to ‘Fallglo’ in time of maturity, response to ethylene, and postharvest behavior.

Modified Atmosphere Packaging for Fresh-cut ‘Kent’ Mango under Common Retail Display Conditions
Sharon Dea, Jeffrey K. Brecht, Cecilia do Nascimento Nunes, and Jean-Pierre Émond
Page 278-289
A modified atmosphere package (MAP) was designed to optimize the quality and shelf-life of fresh-cut ‘Kent’ mango during exposure to common retail display conditions. The synergism between the MAP system and an antioxidant treatment (calcium ascorbate + citric acid) was also investigated. Mango slices in trays covered with polyvinylchloride (PVC) film and an initial atmosphere of 2 kPa O2 were stored at 5 or 15 °C for 10 or 5 days, respectively. Overall sensory quality, firmness, composition, and microbial load were evaluated daily. The MAP system maintained O2 concentrations of 5–6 and 4 kPa at 5 and 15 °C, respectively; however, the corresponding CO2 concentrations were 6–8 and 16–18 kPa. The high CO2 at 15 °C resulted in softer slices compared to samples stored in air. Fresh-cut ‘Kent’ mango slices treated with the antioxidant solution had better visual quality and the shelf-life was extended by 1 d at 15 °C and by 2 d at 5 ºC compared to non-treated fruit. Storage at 5 °C resulted in loss of characteristic mango aroma and development of a plastic-like odor, most likely due to the interaction between the film and the aroma volatiles, suggesting that the type of film used was not suitable for use in a MAP system for fresh-cut mango. The development of a polymeric film with a higher CO2/O2 permeability ratio would most likely enhance the positive effect of MAP on fresh-cut mango when exposed to high temperatures during retail display.

Eating Quality of Old and New University of Florida Strawberry Cultivars
Anne Plotto, Vance Whitaker, and Craig Chandler
Page 290-295
The University of Florida strawberry breeding program has developed cultivars highly adapted to west-central Florida since the 1970s. In this trial, four advanced selections and 11 released cultivars, from ‘Florida Belle’ (1975) to ‘Florida Radiance’ (2008), were grown in a randomized complete-block design with 10-plant plots as the unit of replication. Fruit were harvested bi-weekly and evaluated once a month by a trained sensory panel, from January to March 2010. In January, FL-05-107 had the highest ratings for positive attributes (firmness, sweetness and strawberry flavor). ‘Florida Belle’; ‘Earlibrite’, ‘Strawberry Festival’ and FL-06-38 had high scores for sweetness and strawberry flavor, but were not as firm as FL-05-107. In February, the highest ratings for positive attributes were given to ‘Florida Elyana’ and ‘Strawberry Festival’ while FL-06-38 and ‘Florida Radiance’ were rated high in strawberry flavor. In March, ‘Florida Elyana’, ‘Florida Belle’, ‘Florida Radiance’ and FL-06-38 were also rated high in sweetness and strawberry flavor. FL-05-107 and FL-05-85 were consistently rated high in firmness. On the contrary, ‘Sweet Charlie’ had high sweetness but low firmness ratings in March. The lowest rating for strawberry flavor was given to ‘Dover’ both in January and February, and a high rating given for “overripe/fermented” in January and March, and “sour” in February. ‘Winter Dawn’ also had high ratings for “overripe/fermented” and “woody/musty” in January and March.

Rose Nursery Banker Plants
Juanita Popenoe and Lance Osborne
Page 296-297
Rose nursery plants typically require frequent chemical applications to control pests. Biological control agents and banker plants have been successfully used in greenhouse production, but have not been proven in outside nursery production. In order to reduce pesticide applications in the nursery setting, the use of banker plants and biological control agents in a rose nursery was explored in trials at the Mid Florida Research and Education Center in Apopka. Knock Out™ and ‘Julia Child’ rose plants in 3-gal pots were grown with either overhead or microirrigation. Half of the plants were sprayed with Talstar as needed; the other half received no chemical applications. Banker plants, ornamental pepper (Capsicum annuum ‘Black Pearl’) and field corn (Zea mays), were grown between blocks of eight crop plants. Biological controls Amblyseius swirskii mites, Orius insidiosus, and Neoseiulus californicus will be introduced onto the banker plants as needed to maintain populations. Rose leaves and buds were sampled every 2 weeks to determine pest and predator populations. More pests and fewer biological controls were found in the overhead irrigation plots; however, chilli thrips had not moved into the plots as of the time of writing. The plots will be continued for several more months and pests may be introduced to provide a better test of biological control.

Effects of Solarization against Weeds and Root-knot Nematodes Limited by Weather
Robert McSorley and Harsimran K. Gill
Page 298-301
Soil solarization is a useful nonchemical method for managing a variety of soilborne pest problems. However, it can be difficult for solarization to achieve long-term control of root-knot nematodes (Meloidogyne spp.), which are important pests of many landscape and commercial ornamentals grown in Florida. A field experiment with snapdragon (Antirrhinum majus L.) was conducted in 2009 to determine if performance of solarization could be improved by extending duration of solarization from 6 to 8 weeks, or by combining solarization with other methods, such as incorporating cabbage amendment prior to solarization or by planting a root-knot nematode host such as squash (transplants or seeds) prior to solarization. Frequent cloud cover and low solar radiation during the soil solarization period resulted in relatively low soil temperatures and limited performance of solarization, with weed growth under the clear plastic. A solarization period of 8 weeks was more effective than 6 weeks in limiting (P < 0.001) the number of purslane (Portulaca oleracea L.) plants under the plastic during solarization and in reducing (P < 0.05) number of weed seedlings developing in the subsequent snapdragon crop. Solarization did not have much lasting impact on root-knot nematodes (Meloidogyne spp.), although on one sampling date, root galling was slightly reduced compared to solarization alone when cabbage amendment was combined with solarization or when squash seeds were planted 2 weeks prior to solarization. These methods should be further evaluated under conditions more favorable for solarization.

Efficacy of Fungicides for the Control of Myrothecium roridum on Dieffenbachia picta ‘Compacta’
Robert T. McMillan, Jr.
Page 302-303
Myrothecium leaf spot, caused by the fungus Myrothecium roridum, is a serious disease of Dieffenbachia picta Schott cv. Compacta. In 2009, six products were trialed for efficacy against M. roridum in a shade house. The D. picta plants were started from tissue-cultured liners potted in 6-inch plastic pots. ‘Compacta’ liners were potted for each of the six treatments including an untreated control. Natural infection was allowed to take place prior to the first application of the chemicals. Fungicides were applied on a 7- to 21-d schedule or on a closer interval depending on disease severity and replicated 4 times per treatment. Chipco 26019 (iprodione) at 2 lb per 100 gal of water, Compass O (trifloxystrobin) at 1 oz per 100 gal of water, Daconil 2787 (chlorothalonil) at 1.5 lb per 100 gal of water, Heritage (azoxystrobin) at 4 oz per 100 gal of water, Medallion (fludioxonil) at 2 oz per 100 gal of water, and Systhane (myclobutanil) at 2 oz per 100 gal of water were significantly more effective in the control of Myrothecium leaf spot than copper at 1.5 lb per 100 gal of water.

Control of Royal Palm Bug (Xylastodoris luteolus) Populations with Soil Applied Neonicotinoid Insecticides
Douglas L. Caldwell and A.D. Ali
Page 304-307
The royal palm [Roystonia regia (Kunth) O.F. Cook] is a majestic and prized palm tree in South Florida landscapes and has relatively few pests. However, sudden population flare-ups of the royal palm bug (RPB) [Xylastodoris luteolus Barber (Hemiptera: Thaumastocoridae)] can be severely damaging. Damage appears as tan-gray, ragged new growth that reduces aesthetics and may affect photosynthetic ability. This study was conducted to evaluate the efficacy of soil-applied neonicotinoid systemic insecticides. All three active ingredients were tested at 0.05 oz a.i. (1.4 g) per inch trunk diameter. All of the treatments tested: Merit 2F (imidacloprid), Safari 2G and Safari 20 SG (dinotefuran), and Arena 50 WDG (clothianidin) provided excellent RPB control at 30 and 75 days after treatment. ELISA analysis of palm foliage showed dinotefuran translocated fastest, followed by imidacloprid then clothianidin. Compared to high-pressure foliar spraying, soil application of systemic insecticides is preferred in urban landscapes because the drift risk is eliminated. This is especially apt when treating tall palms with small canopy areas (in relation to hardwood tree canopies). High-visibility, specimen royal palms used to be treated preventively due to a presumed, long translocation period of imidacloprid. Now palms can be effectively treated curatively, since translocation occurs within 30 days.

I ntegrated Impact of Soil Solarization and Organic Mulching on Weeds, Insects, Nematodes, and Plant Performance
Harsimran K. Gill and Robert McSorley
Page 308-311
Soil solarization is a hydrothermal method to increase soil temperature for managing soilborne plant pests that include insects, weeds, nematodes, and fungi, while mulching is an effective way to control weeds along with providing shelter for predatory insects. The integrated impact of soil solarization and mulching on weeds, nematodes, insect pests, and plant performance was evaluated in field-grown ‘Potomac Pink’ snapdragon (Antirrhinum majus L.) in Fall 2008 at the University of Florida Plant Science Research and Education Unit, Citra. Four treatments were compared: solarization (S), mulch (M), integration of mulch and solarization (MS), and an untreated control (C). Treatments were arranged in a randomized complete-block design with five replications. For the mulch treatment, a preplant mulch of sunn hemp (Crotalaria juncea L.) hay was applied over the bed surface. In the solarization treatment, beds were covered with Polydak® plastic film for 6 weeks. After 6 weeks, the plastic was removed, and all beds were planted with snapdragons. For MS treatment, plastic was applied as preplant, and sunn hemp mulch as postplant application. Data were collected on the mortality of snapdragon plants, weed ratings, nematode counts in soil, plant parameters (plant weight and number of blooms), and visual count of insects, especially buckeye caterpillar (Junonia coenia Hübner, Lepidoptera: Nymphalidae) and saltmarsh caterpillar [Estigmene acrea (Drury), Lepidoptera: Arctiidae]. Solarization or mulching alone reduced weed numbers but integration of solarization and mulching provided the most effective control of weeds. Population levels of large buckeye caterpillars were highest in the MS treatment. Plant mortality and plant parameters did not differ among the treatments. Extensive plant damage and mortality due to caterpillars were observed in all plots.

Performance of Low-maintenance Roses in Central Florida
Jozer Antonio Mangandi and Sydney Park Brown
Page 312-314
Roses (Rosa spp.) are some of the most cultivated flowers in the world. Cultivars of modern roses, such as hybrid teas, are popular; however, most demand intensive maintenance. Florida’s climate and soil conditions make many roses particularly difficult to grow in the state. Performance of roses under low-maintenance conditions has been assessed in Texas and Mississippi but little information is available for Florida. The purpose of this study was to assess the performance of certain rose cultivars under a low-maintenance regime and to ultimately be able to recommend cultivars which perform well as shrub roses in the central Florida landscape. An evaluation of 12 rose cultivars began in 2008. Cultivars selected were listed as Earth Kind™ roses and/or were reported to be reliable performers in Florida. Soil was amended prior to planting with composted cow manure to a depth of 6 inches and woven landscape fabric was placed over the beds. Own-root plants were placed on 8-ft-wide beds with 8-ft spacing between plants. A 3-inch layer of fine-ground pine bark was added to the top of the fabric. Plants were not pruned, nor were pesticides used. Drip irrigation supplied water at 0.5 gal/plant/week once during the rainy season and twice during the dry season. Roses were fertilized with Osmocote Plus 15–6–12 . Weekly evaluations of visual quality and flower coverage were assessed for 2 years.

Water Quality Issues Facing Florida Growers
Brian J. Boman and Thomas A. Obreza
Page 315-321
Point source discharges have been regulated for many years under the 1972 Clean Water Act (CWA). Even though limits on point source discharges have become more stringent over time, many water bodies still fail to meet the standards defining good water quality. Therefore, efforts to reduce non-point impairment sources have become a major focus of reducing loadings to water bodies during the last decade. Under the authority of section 303(d) of the CWA, the U.S. Environmental Protection Agency (EPA) requires that Total Maximum Daily Loads (TMDLs) be developed where technology-based effluent limitations or other legally required pollution control mechanisms are not stringent enough to protect water quality. TMDLs describe the amount of each pollutant a water body can receive without violating standards, and are characterized as the sum of pollutant loads of existing and future point sources (e.g., discharges from industry and wastewater treatment facilities), loads from existing and future nonpoint sources (e.g. runoff from farms and urban areas), and natural background loads. TMDLs have been developed or are in the process of being developed for much of peninsular Florida, and as a result, will affect agricultural operations whenever they are developed and implemented through Basin Management Action Plans (BMAPs). The management strategies that emerge from the TMDL process may encompass everything from traditional regulatory measures, agricultural Best Management Practices (BMPs) and other pollution prevention measures, land acquisition, infrastructure funding, pollutant trading, and the like. They also will include an overall monitoring plan to test their effectiveness. This paper discusses the TMDL/BMAP development and implementation in Florida, the role of agricultural BMPs in meeting the TMDLs, and recent concerns arising from the Numeric Nutrient Water Quality Criteria being proposed by EPA.

Considerations for Reclaimed Water Use in the Nursery
Thomas H.Yeager
Page 322-323
Reclaimed water (processed sewage) can be an effective substitute for municipal, well, and surface water, and its use may improve profitability and conserve natural resources in the container nursery. However, limited use of reclaimed water for irrigation of container-grown plants is probably due in part to its lack of availability to container nurseries. Nonetheless, users and potential users should consider the following when using reclaimed water: the processor’s standards for reclaimed water quality, quantity of reclaimed water needed, infrastructure required for reclaimed water use, permits, signage, costs for the user, and social aspects. A contract with the supplier can be used to address several of these considerations. While, contracts may seem burdensome, a reliable supply of quality irrigation water during drought restrictions is likely worth the diligence.

The Importance of Water Quality for Food Safety
Alicia Whidden
Page 324-325
Food safety has become an important issue to consumers and is reported on frequently by national media. From 1990 to 2005, there were 713 documented produce-related foodborne illness outbreaks in the United States. Food safety has become a major initiative of the US government. Now, major retail food chains are requiring third party food safety audits of the producer and packinghouse before buying produce from a company. One of the criteria of food safety audits is the safety of the water that is used to irrigate produce or wash produce for packing. Issues relating to producers meeting food safety audit standards and state mandatory food safety standards when required and the water permitting constraints that the state Water Management Districts impose will be discussed as well as public opinion on food safety and water issues.

Installation of a Bioretention/Rain Garden to Mitigate Agricultural Irrigation Runoff from a Container Plant Nursery
Alex Bolques, Jennifer Cherrier, Michael Ababazinge, and Geldar Matungwa
Page 326-329
Bioretention and rain garden systems are shallow planted areas designed to capture, retain, or detain stormwater to encourage soil infiltration of water that would otherwise run off over the soil surface. Benefits to the environment associated with rain gardens include: improved water quality, enhanced groundwater recharge, suspended particle reduction, reduced surface flows and associated erosion, and habitat creation for birds, butterflies, and beneficial insects. In 2008, a rain garden system was installed at a container plant nursery in northern Florida to evaluate the effectiveness of bioretention to mitigate irrigation associated nutrient loading to adjacent wetlands, water bodies, and groundwater. Irrigation runoff from an impervious production bed that is 360 ft × 50 ft (109.7 m × 15.2 m) flows into one of two rain gardens that are approximately 25 ft × 15 ft (7.6 m × 4.6 m) in size. The garden soil consists of ASTM C-33 sand and is approximately 34 inches (86.4 cm) deep with under-drains. The gardens are side-by-side, separated by a constructed 3-ft- (0.9 m) wide clay soil partition, with one designated as planted and the other non-planted. Three native plants species, Hydrangea quercifolia (oakleaf hydrangea), Serenoa repens (saw palmetto), and Canna flaccida (canna lily), were installed in the planted garden. Studies are currently under way to monitor nitrogen, phosphorus, and zinc, pre- and post-exposure to the rain garden. It is anticipated that results from this study would supplement current best management practices for container plant nurseries in Florida for associated nutrient loading from bed irrigation runoff.

Description and Performance of Four Eucalyptus grandis Cultivars Released by IFAS/UF in 2009
Donald L. Rockwood and Bijay Tamang
Page 330-332
Genetic improvement of Eucalyptus grandis for Florida conditions started in the 1960s. Substantial improvements in the species’ growth, form, and freeze resilience have been achieved, culminating in the release in 2009 of the four commercial cultivars Energy™ G1, G2, G3, and G4. While G1, G2, G3, and G4 have exceptional growth rate, stem form, freeze tolerance, and coppicing ability compared to 4th-generation E. grandis seedlings, the four cultivars have important differences in these characteristics, their genetics, and wood properties. Planted at five locations throughout peninsular Florida in 2009, the cultivars survived well, were up to 6.1 m (20 ft) tall in 8 months, and typically tolerated the exceptionally cold weather of Jan.–Feb. 2010. Their deployment expanded in 2010, and they will be widely available for future commercial energywood farms and other uses in southern, central, and even northern Florida. Research continues to develop even more superior E. grandis cultivars.

Bringing Master Gardening to Costa Rica
Daniel F. Culbert, Alejandro Bolques, Larry Halsey, Adrian G.B. Hunsberger, Henrique Mayer, David W. Marshall, Linda M. Seals, Pete Vergot, Luis N. Bulgarelli, and B.K. Singh
Page 333-338
The University of Florida Extension Service initiated Costa Rica’s first training of non-formal landscape managers in 2008. Three county agents and two administrators spent a week in Apr. 2007 visiting EARTH University’s new LaFlor campus near the Pacific coast. That region is experiencing rapid growth in tourist development. Stresses of rapid growth, decreased water quality and quantity, and misuse of horticultural chemicals now impact the local economy and environment. In 2008, seven county agents provided two concurrent 7-week programs. Each agent spent 2 weeks at LaFlor. Agents rotated in and out each week for program continuity. Course materials and lessons were taught in Spanish. The “Master of Gardens” program was designed for nursery and landscape professionals. The “Gardeners of Costa Rica” course focused on homeowners and ecotourism personnel. Participants learned about best management practices suitable to the dryland tropics, practiced concepts with hands-on exercises, and installed demonstration gardens. After 7 weeks, a graduation ceremony was held and 47 participants received completion certificates. Pre/post, testing results showed up to 38% improvement in test scores on the concepts taught. Follow-up activities include an ongoing website. Materials developed will be utilized in Florida to deliver programs to Spanish-speaking audiences. This project provided an international experience for Extension faculty to broaden their knowledge of different environments and cultures.

Communicating Landscape Freeze Damage to the Public in Charlotte County
Ralph E. Mitchell
Page 339-340
The freezing and frosty weather of January, February, and March 2010 saw some nighttime temperatures in the 30s and as low as 23 °F in the Charlotte County area. This was the second year in a row with widespread damaging freezes. The 2010 cold spell was worse, however, with longer cold temperatures that certainly laid waste to our local landscapes. Communicating how to deal with our potentially cold weather in Charlotte County is an annual event. Besides communicating verbally to our customers on the phone, in person and in group programming, we expanded our outreach with additional written media releases and by using electronic media and techniques to take advantage of this “teachable moment.” This was an opportunity to market Extension and educate our public as we emphasized EDIS publications through our newspaper articles, used educational slide shows on our website, and took advantage of special press releases by State Specialists. A timely group program on landscape palms, as well as a PolyCom© session with a State Specialist rounding out the educational experience related to freeze damage. In addition to a measurable spike in website hits linked to an increase in customer information searches, an electronic survey of over 500 customers was conducted related to the freeze damage which documented interesting results.

A Methodology for Building Community Leader Support for Good Tree Care
Michael S. Orfanedes
Page 341-343
Good urban tree canopy does not happen by itself. Rather, it must be planned for by people who place a high value on trees, have a vision for building an urban forest and have the time and resources needed to make their vision reality. Transforming a personal vision for tree canopy into reality at the community level requires community buy-in. Stakeholders and decision makers in the community must share the vision or at least support it in order for that vision to become reality. Building support for community tree canopy begins with education and a community landscape committee is a good way to start. Volunteers plan and conduct outreach to teach others in the community, especially decision makers, about the value and beauty of trees, the important environmental services they provide and the best practices needed to establish and maintain them. The committee can also communicate ideas for beautification projects, identify maintenance needs, and make observations about contractor performance to property managers and the board of directors. This presentation will focus on one South Florida community’s journey to rebuild its canopy in the aftermath of Hurricane Wilma and the role that outreach and an active landscape committee played to achieve that goal.

Evaluating How Accurately Lawn Fertilizers Are Applied Using Homeowner Equipment
Steven Arthurs and Karen Stauderman
Page 344-347
Inappropriate use of fertilizers in urban environments has been implicated in increased nutrient loads in Florida water bodies. We tested how accurately lawn fertilizers were applied by 36 master gardeners and other volunteers. Subjects were asked to apply a label rate of fertilizer [30% fine granular slow-release formulation (32–0–10) at 1.37 kg/100 m2 (2.81 lb/1000 sq ft) and a coarse granular readily available nitrogen fertilizer (10–0–10) at 3.17 kg/100 m2 (6.5 lb/1000 sq ft)] using three spreaders [a hand-held rotary, a broadcast rotary (push), and a drop spreader]. Results showed that under the test conditions applications using the hand-held rotary spreader were the most accurate (averaging 98% of target rate over two tests), while applications using the push rotary spreader tended to be over-applied (138% to 301% of target rate), and those of a drop spreader tended to be under-applied (31% to 48% of target rate). Our simple study highlights that lawn fertilizers are not always accurately applied. Sources of error included variability in applicator walking speed, inaccurate swath widths (e.g., too narrow with push rotary or too wide with drop spreader), and the amount of fertilizer loaded into hoppers. A good approach to provide a quick check of overuse or underuse is for applicators to determine the area to be treated and calculate and weigh the required amount of fertilizer before application. The inclusion of a volumetric measurement on the bag label (in addition to weight) would facilitate calibration for homeowners without requiring access to weigh scales.

An Educational Model to Facilitate Mandated Environmental Behavior Change
Michael S. Orfanedes and Angelina C. Toomey
Page 348-349
Concern over widespread ongoing tree abuse that was creating safety hazards for the public and threatening the health and longevity of the tree canopy in Broward County, FL, led the Board of County Commissioners to adopt an ordinance regulating the tree trimming industry in 2000. Known as the Broward County Tree Trimmer Licensing Ordinance, this legislation mandated that each organization that performs tree trimming obtain a license. One of the requirements for obtaining a license was passage of a mandatory training class that included a competency exam. Through extensive grass roots planning, a hands-on training curriculum for basic pruning was developed by UF-IFAS Broward County Extension. Curriculum materials were prepared and instructors were recruited and trained. Classes were conducted in English, Spanish, and Creole to meet the needs of this diverse industry. The combination of field-savvy instructors, lots of visual presentations, and outdoor “hands-on” pruning demonstrations has served the industry well. To date, nearly 5000 individuals have been trained. Special accommodations in the form of verbal exams, free retakes, and skills demonstration exams have been popular with learning impaired and functionally illiterate students. Continuing education classes have been developed to provide training in tree biology and hazard assessment, storm preparedness, and recovery pruning and safety. In a random sample of 104 trained tree trimmers, 94% (98) described the classes as providing a significant benefit to their business operations. Nearly the same percentage reported sharp reductions in hat-racking, over-lifting and flush-cutting of hardwoods and over-pruning of palms. This model of education has been successful because of its service orientation and relentless commitment to making every student’s experience a positive one. It has professionalized the industry and made the tree canopy safer and healthier.

Assay of Citrus Seed for Viable Xanthomonas citri pv. citri (Xcc) after Extraction from Fruit Affected by Citrus Canker
James Graham, Mike Irey, and Chuck Reed
Page 350
Trees for production of seed of rootstocks for citrus nursery propagations are typically located in blocks planted outdoors and are unprotected from pathogen and pest infestations. A seed-tree block in Dundee, FL, experienced an initial incursion of citrus canker in July 2009. By Sept. 2009, canker had spread in the block from south to north in the tops of Swingle citrumelo and Carrizo citrange trees. The disease distribution suggested that the Xcc inoculum was introduced in a single windblown rain event. This case illustrates the high risk for outdoor seed-tree blocks in Florida nurseries to become infected with canker. The purpose of this study was to provide evidence that the seed extraction and disinfection process for treating against fungi utilizing hot water, fungicide, and bleach treatments is effective for eliminating Xcc from seed harvested from canker-infected fruit. The Carrizo citrange fruit used for seed extraction in this experiment exhibited moderate to severe canker symptoms. Seed extracted from the fruit were subjected to the standard hot water/fungicide treatment and then were assayed for the presence of Xcc. To validate the assay process, seed were soaked in Xcc inoculum at 104 colony forming units per milliter; then they were washed, and the wash solution infiltrated into grapefruit leaves for detection of viable bacteria. The presence of canker lesions in the grapefruit confirmed that the recovery and bioassay methods were effective for detection of viable Xcc in seed washes. Treatments of seed extracted from canker-infected fruit with hot water at 125 °F for 10 min and 8-hydroxyquinoline sulfate, with or without 10% bleach in the wash step nullified recovery of viable Xcc. This was expected since each of the disinfectants has bactericidal activity. In conclusion, the protocol for extracting and disinfecting citrus seed was effective for Xcc disinfection of seed from canker-infected fruit.

Using Strawberry Variety Taste Testing to Promote Agricultural Education and Determine Consumer Preferences
James DeValerio, Aparna Gazula, Eric H. Simonne, and Amarat Simonne
Page 351-352
Strawberry (Fragaria ×ananassa Duch.) taste tests are popular activities that have enlisted public participation in educational activities that promote agricultural awareness in Bradford County. Although the roughly 15 to 18 acres of production pale in comparison to strawberry production in central Florida, the few local producers benefit greatly by direct marketing their crop at an average value of $12 per flat. Six strawberry taste tests were organized during the 2007, 2008, and 2009 Bradford County fairs and festivals to determine 1) pre-taste-test variety familiarity, and 2) consumer preferences for ‘Camino Real’, ‘Camarosa’, ‘Festival’, ‘Sweet Charlie’, and #116 varieties. Using a 0 to 9, low to high preference scale: mean ranges were 5.6 to 6.7 (for color), 5.1 to 6.3 (for flavor), 5.1 to 6.8 (for firmness), and 4.4 to 7.2 (for overall score) between all varieties. Surprisingly only 4% of the consumer panelists were able to name a strawberry variety prior to testing. Using the strawberry taste tests provided educational opportunities to discuss strawberry production and handling practices during a fun, teachable experience.

Junior Master Gardeners Explore Alternative Gardening Methods Growing Fruits, Vegetables, and Cut Flowers
Alicia R. Lamborn

Page 353

No abstract.

Magazine and Online CEU Articles as Possible Models of Educational Opportunities for Pesticide Applicators and ASHS Certified Horticulturists
Mary Lamberts, Edward A. Skvarch, and Gary K. England
Page 354
No abstract.

Vegetable Water Quality and Quantity BMP Collaboration in West-central Florida
Crystal Snodgrass, Alicia Whidden and Jemy West Hinton

Page 356-357

No abstract.