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Foliar Insecticides for Control of Insect Pests on Tomatoes A.B. Smith, N.B. Shamiyeh, and J. Cranmer Interpretive Summary No significant difference was found in the yield of No. 1 and No. 2 tomatoes from the different treatments. No phytotoxic effects were found with any of the plots treated with the S-1812. Introduction Several chemical and biological control agents are available for use against insect pests and pathogens of tomatoes. The commercial use of the bio-control agents suffers from lack of understanding about their efficacy, and possible integration with traditional and other IPM methodologies of control. An efficacy trial was conducted at the Plateau Experiment Station at Crossville to evaluate new biological control agents against lepidopteran tomato pests. These were also combined with, and compared to some traditional chemical control agents. Materials and Methods Thirteen foliar insecticide treatments were compared to an untreated control for efficacy in controlling lepidopteran pests on tomato. Fertilizer was broadcast at 450 lb/A of 15-15-15 before final disking and four foot wide plastic mulch with trickle tape was laid June 9. ‘Celebrity’ plants were transplanted into the plot on June 12. Plot size was one row, 15 ft long, with 8 feet between rows. Each row contained 10 plants, and were tied using a Florida Weave system. Weed control was shield applied 0.5 lb ai/A paraquat (Gramoxone Extra) in row middles as needed. Chlorothalonil (Bravo) at 1.5 lb ai /A alternated with dimethamorph (Acrobat) at 0.45 lb ai/A was used for disease control. Experimental plot design was a randomized complete block with four replications. Insecticides being tested were applied on Aug. 1, Aug 11, Aug. 19, Sept. 3, and Sept. 12 using a 2.5 gallon CO2 hand sprayer at 45 gallons per acre and 40 psi. Plots were hand harvested five times between Aug. 9 and Sept. 18. Evaluations of the plants were made before each picking to determine worm pressure on the plants. Tomatoes were graded into grades of No.1, No.2, and cull. All data were analyzed by analysis of variance method, and means were separated by Duncan’s multiple range at the 0.05 level of probability. Results and Discussion No significant difference was found in the yield of No. 1 and No. 2 tomatoes from the different treatments (Table 1). The plots treated with Danitol at 0.200 Lb ai/A was among several treatments that had lower yields of cull grade fruit. The S-1812 treated plots, and plots treated with S-1812 mixed with another chemical were among treatments with lower percentages of damaged fruit. No phytotoxic effects were found with any of the plots treated with the S-1812. Table 1. Treatment, yield in tons per acre of No.1, No.2 and cull grade fruit and percentage of damaged tomatoes for various insecticide treatments at the Plateau Experiment Station, Crossville, 2003.
z Means within a column followed by the same letter are not significantly different at the 0.05 level of probability, Duncan’s multiple range tests. |
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