Progress 03/01/04 to 03/01/10
Outputs
OUTPUTS: The effect of Vydate L on yield and fruit quality of crookneck squash in the absence of pests was investigated. Beds were shaped, Aquatrax TM drip tape (12 inch emitters flowing 0.45 gal/min at 12 psi) placed in the center and covered with 1 mil black polyethylene mulch. Telone and metam sodium were applied at the time beds were being formed and covered with polyethelene mulch. Plots were 25 feet long, replicated five times and arranged in a randomized complete block design. Yellow crookneck squash variety 'Prelude II' was transplanted into test plots on single rows 07 April. Plant spacing was 12 inches. Individual treatments of Vydate L at 2.0 qts/A were applied through the drip tape on 14, 28 April and 12 May post-transplant. Vigor ratings were conducted on 22 April, and 01, 09, 15, 21, and 27 May. Plant vigor was rated on a scale of 1 to 10, with 10 representing vigorous, healthy plants and 1 representing dead plants. Height measurements were taken on 01, 09, 15, and 22 May. Height measurements were recorded in centimeters measuring plants from the base of plant to the tip of the longest leaf. All squash fruit were hand harvested from all plants in each bed. Fruits were harvested when they were immature, approximately 6 inches long, with a light yellow color and soft flesh that could be easily pierced, and when flowers were desiccated and/or abscised from fruit. Each harvest was separated into marketable and cull fruits per plot number, counted and weighed in pounds. Marketable fruits were then graded by commercial sizes. Each squash fruit was passed through one of four round openings of a designated diameter. Numbers of squash fruit in each size category was recorded for each plot number. There were a total of six harvests and grades done on 09, 14, 20, 27, 30 May and 03 June. Squash roots were dug 05 July and a root gall evaluation was conducted using a 0-10 scale. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The application of Telone C-35 metam sodium, and Vydate had little effect on plant vigor, plant height, yield, quality or root knot damage of yellow crookneck squash in the absence of pathogens or root knot nematodes. This would suggest that the application of these pesticides in the absence of pathogens or nematodes would increase the cost of production at the grower level. In summary, the spring of 2008 was a good year for vegetable production and this trial yielded an excellent crop. Statistically (P=0.05) there were no differences among treatments for any of the evaluated parameters. However, Telone C-35 + Vapam + Vydate L treated plots had the greatest vigor, tallest plants, and highest marketable weight numerically. Average vigor ratings ranged from 9.3 to 8.8 on the non-treated, but were not statistically different from each other. Height measurements were lowest in the non-treated at 49.5 cm and Telone C-35 + Vapam + Vydate L treated plots were significantly taller than the non-treated. Total marketable fruit per plot and total yield were not statistically different (P=0.05) among treatments. No differences among treatments were detected for fruit grade; Fancy, US # 1, US # 2, and large. Root galling was trace on root systems and no differences were detected among treatments.
Publications
- Kone,D., Ji, P., Fonsah, G. E., and Csinos, A. S. 2008. First report of black leaf spot of banana caused by Deightoniella torulosa in Georgia. Plant Disease 92:1470.
- Ji, P., Csinos, A. S., Hickman, L. L., McMillan, J., and Hargett, U. 2008. Evaluation of V-10161 to control Phytophthora fruit rot on tomato. Plant Disease Management Reports 2:V176.
- Ji, P., Csinos, A. S., Hickman, L. L., McMillan, J., and Hargett, U. 2008. Integrated use of Ridomil Gold and other compounds for management of Phytophthora blight in squash. Plant Disease Management Reports 2:V178.
- Ji, P., Csinos, A. S., Hickman, L. L., McMillan, J., and Hargett, U. 2008. Evaluation of V-10161 to control Phytophthora blight on squash. Plant Disease Management Reports 2:V177.
- Yin, J., Jackson, K. L., Csinos, A. S. and Ji, P. 2008. Potential of phosphorous acid-containing products for control of Phytophthora blight on squash. Phytopathology 98:S177.
- Kone, D., Csinos, A. S., Yin, J., and Ji, P. 2008. Evaluation of cover crops for management of Phytophthora blight on squash. Phytopathology 98:S84.
- Kone, D., Ji, P., Fonsah, E. G., and Csinos, A. S. 2008. Assessment of foliar and root diseases of banana and plantain in Georgia. Phytopathology 98:S84.
- Ji, P., Csinos, A. S., Langston, D. B., and Kone, D. 2008. Management of Phytophthora blight caused by Phytophthora capsici in Georgia. Pages 5-6, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
- Ji, P., Csinos, A. S., and Langston, D. B. 2009. Updating the battle against Phytophthora capsici. Page 28, in: Proceedings of the Southeast Regional Vegetable Conference. Savannah, GA.
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Progress 01/01/07 to 12/31/07
Outputs
The effects of metam-sodium application rate on soil residence time, spatial and temporal distributions of methyl isothiocyanate and pest control efficacy were studied in a Georgia sandy soil. Metam-sodium 420 g L SL was drip applied at rates of 147 and 295 L ha in plastic-mulched raised beds. Methyl isothiocyanate concentrations in soil air space were monitored from four preselected sites: 10 and 20 cm below the emitter, and 20 and 30 cm laterally away from the emitter at 3, 12, 24, 48, 72, 120 and 240 h after chemigation. A higher rate of metam-sodium application resulted in higher methyl isothiocyanate concentrations in the soil. Highest methyl isothiocyanate concentrations were found at 20 cm below the emitter, and lowest at 30 cm laterally away from the emitter. Methyl isothiocyanate concentrations decreased with time and distance from the emitter. Lower methyl isothiocyanate concentration x time product values at 20 and 30 cm away from the emitter resulted in
lower mortalities of Rhizoctonia solani Kuhn and yellow nutsedge (Cyperus esculentus L.). The results demonstrated that methyl isothiocyanate can be delivered at lethal doses with drip-applied water downward within the beds. Lateral diffusion of methyl isothiocyanate from the point of application did not reach biologically active concentrations to affect the survival of R. solani or yellow nutsedge. Further studies on the lateral distribution of methyl isothiocyanate in sandy soils are needed to circumvent this limitation.
Impacts
The work described in this project underscores the problems associated with water miscrible fumigants. Materials being delivered with water tend to act as contact materials rather than fumigants and thus have restricted activity in the soil profile. These materials are only active in the areas that are reached by the delivery water, which in sandy loams are restricted. Techniques to increase the percentage of the soil profile will need to be developed for these type of materials to be active.
Publications
- Candole, Byron L., Csinos, Alexander S., and Wang, Dong. 2007. Distribution and efficacy of drip-applied metam-sodium against the survival of Rhizoctonia solani and yellow nutsedge in plastic-mulched sandy soil beds. Pest Manag Sci 63:468-475.
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Progress 01/01/06 to 12/31/06
Outputs
Concentrations and biological activities of 1,3-dichloropropene (1,3-D)and methyl isothiocyanate (MITC) in raised plastic-mulched beds were studied. Gas levels of 1,3-D and MITC were monitored for 10 days (after drip irrigation application) from the soil atmospheres at different locations within the raised plastic-mulched beds treated with InLine ([60.8% 1,3-D+33.3% chloropicrin], [95, 190, and 285 l/ha]) and Vapam ([42% metam sodium EC], [238, 473, and 710 l/ha]), respectively. Highest 1,3-D and MITC concentrations were observed at 10 and 20 cm below the emitter 24-48 hrs after application and decreased with time and distance from the emitter thereafter. Survival of Phytophthora capsici and Rhizoctonia solani AG-4 from artificially infested beet seeds embedded for 10 days in the soil was reduced from 87-98% 10 cm below the emitter for 1,3-D and MITC but only by 28-62% at 10 cm depth, 20.3 cm away from the emitter. Yellow nutsedge tuber mortality increased by 84-135%
10 cm below the emitter and 2.5-71% at 10 cm depth, 20.3 cm from the emitter. P. capsici, R. solani, and yellow nutsedge survival was reduced by 95%, 80%, and 77%, respectively, after 24 hrs of exposure in the soil atmosphere (at 10 cm depth, 20.3 cm from the emitter) of beds treated with 710 l/ha Vapam. The results demonstrated: (1) the poor ability of these methyl bromide alternatives to diffuse at toxic concentrations beyond the point of application reduces their efficacy against soilborne pathogens and weeds. (2) propagules have to be killed within 24 hrs of exposure after application for treatments to be effective due to rapid decline in concentrations of these chemicals in the soil atmosphere over time, and (3) improved application techniques will be required to improve the efficacy of these alternatives. The results on soil gas concentrations are significant in providing data that can be used as input variables for the development of a computer program for making management
decisions in soil fumigation. The CT values were important in establishing a threshold CT value for each chemical-pest combination for treated soil beds.
Impacts
The results from the project illustrated the need for studies on application techniques to (a) enhance the efficacy of methyl bromide alternatives such as metam sodium, 1,3-dichloropropene and chloropicrin, and (b) to minimize losses of these water-based alternatives with the downward movement of water. The latter addresses the issue of minimizing or preventing possible contamination of the ground water table.
Publications
- Candole, B.L., Csinos, A., and Wang, D. 2007. Distribution in soil and efficacy of drip-applied metam sodium against the survival of Rhizoctonia solani and yellow nutsedge in plastic-mulched beds. Pest Manag. Sci. 00:0000-0000 (In press).
- Candole, B.L., Csinos, A., and Wang, D. 200x. Distribution in soil and efficacy of drip-applied 1,3-D + chloropicrin and metam-sodium in plastic-mulched beds. Crop Prot. 00:0000-0000 (Accepted).
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Progress 01/01/05 to 12/31/05
Outputs
Phytophthora capsici is a persistant soil borne disease that causes serious losses to cucurbits, peppers and tomatoes in Georgia. Two trials using drip application under plasticulture and a single trial on bare ground was established in the P. capsici nursery at the Black Shank Farm, Tifton, GA and planted to yellow squash cultivar, Prelude II. None of the treatments in the Drip 1 test were significantly different from the non-treated control in the total yield, or marketable yield. However, total number of fruit was increased, and disease index and percent diseased plants decreased from Prophyt at 8 pt/A applied six times. In Drip 2 test, only Ridomil Gold plus mandipropamid had total yield higher than the non-treated control. Although no other treatments showed significant differenced from the non-treated control, several treatments tended to have reduced disease and increased yields. In the foliar applied study only Reason plus Previcur flex had significantly
higher total yield and marketable yield, than the non-treated control. However, several treatments, Reason plus Previcur flex, Ridomil Gold plus mandipropamid, Prophyt plus Bravo, V-10161 plus Previcur flex, and Captan plus TM-473 reduced the disease index over the non treated control. In the test where film mulch covered the bed and drip tape was used to deliver the chemicals, the main form of damage was root and crown rot. In the bare ground study where materials were applied as foliar sprays, the main form of damage was crown and fruit infections. It is of interest to note that Reason plus Previcur flex did not perform well as a drip application but did well as a foliar application. Prophyt plus Bravo caused a phytotoxic response as a foliar application, but caused no phytotoxicity problem and did very well as a drip application. These tests would suggest that some products applications methods may influence efficacy of the fungicides.
Impacts
Most of Georgia's vegetable production is under double cropped plasticulture. The research we are conducting will help define precise chemical application through microirrigation systems to improve efficacy, reduce use patterns and reduce environmental exposure of pesticides.
Publications
- Dye injection for predicting pesticide movement in micro-irrigated polyethylene film mulch beds. Alex S. Csinos, James E. Laska and Stan Childers. 2002. Department of Plant Pathology, The University of Georgia, Coastal Plain Experiment Station, Tifton, GA 31793-0748 Dow AgroSciences, Indianapolis, IN 46268-1054
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Progress 01/01/04 to 12/31/04
Outputs
The use of a blue agricultural dye was employed to investigate the movement of water and potentially chemical laden water through soil beds covered with polyethylene film mulch, (PEFM). The water soluble dye was applied through drip tape under PEFM and several application scenerios were investigated. The soil used was a sandy (88% sand) loam and 32 inch wide beds were formed using a commercial bed former and plastic-drip-tape applicator. The beds were dissected after the dye application and the blue pattern resulting from the application analyzed for special distribution. The length of time of water application, the water pressure and drip tape configuration all had significant effects on the distribution of the blue dye in the soil. Generally longer irrigation times of up to 8 hours provided the greatest coverage of the bed volume. Pressure increases to 20 psi increased water volume and increased distribution in the soil bed. The spacing of the drip emitters was
critical to the distribution of the dye in the soil profile. Incorporating all of the factors to optimize the distribution of the dye in the soil failed to provide complete coverage of the entire soil bed profile in the sandy soil used in this study. Implications of poor water and pesticide distribution are discussed.
Impacts
Most of Georgia's vegetable production is under double cropped plasticulture. The research we are conducting will help define precise chemical application through microirrigation systems to improve efficacy, reduce use patterns and reduce environmental exposure of pesticides.
Publications
- Csinos, A. S., J. E. Laska and S. Childers. Dye injection for predicting pesticide movement in micro-irrigated polyethylene film much beds. 2002. Pest Manag Sci 58:381-384.
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