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Foliar Insecticides for Control of Insect Pests on Peaches A.B. Smith, N.B. Shamiyeh, and J. Cranmer Interpretive Summary Aphids were the only insects present in significant numbers. All chemical treatments resulted in fewer aphid colonies than the untreated trees. No significant differences were found between the chemical treatments. Introduction Peach production in Tennessee has fallen in recent years to about 900 acres, but this still accounts for a substantial cash crop for the state. According to the Tennessee Department of Agriculture, in fiscal year 2002 peach production brought farmers in the state $1.7 million. Several insects are known to feed on peach trees and fruit. With recent and pending bans on several insecticides used to control pest problems new alternatives are needed. For this reason a test was conducted at the Plateau Experiment Station in Crossville to test the efficacy of some insecticide treatments. Materials and Methods A plot was measured out in an established orchard of ‘Reliance’ trees. Row spacing is 20 ft with 20 ft between trees. Plots were a single tree, with trees of similar size being used for all treatments. Disease control was Dithate at 4.8 lb ai/A during bloom, with Captan at 2.93 lb ai/A and benomyl methyl (Benlate) at 0.19 lb ai/A on a ten day interval beginning after petal fall. Test materials were applied using a Solo motorized backpack sprayer calibrated to spray 40 gal/A. Test treatments were sprayed on July 21, Aug 4, and Aug 13. Evaluations were made once a week for insect infestations. Experimental design was randomized complete block with four replications. 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 Aphids were the only insect to appear in significant numbers on apple trees during the 2003 season. No significant mite populations were detected in the orchards including the control trees. Trees with all treatments had significantly fewer aphid colonies than the untreated trees on Aug 1 and Aug 14 (Table 1). August 21 evaluations found the untreated trees having a similar number of aphids to treated trees. No significant differences were found between the treatments on Aug 1 and Aug 14, but trees treated with Guthion had significantly fewer aphid colonies present compared to the Danitol treated trees on Aug 21. A heavy rain a few days earlier could be the explanation. Table 1. Treatment, rate and number of aphid colonies on peach trees treated with insecticides at the Plateau Experiment Station, Crossville.
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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