Pea Aphid Control on Field Pea, 2010

Abstract

Pea aphid: Acyrthosiphon pisum (Harris)The purpose of this study was to evaluate the efficacy of insecticides at pre-bloom, early pod, and late pod timings for the control of pea aphids on field pea. The experiment was conducted at the North Dakota State University North Central Experiment Station south of Minot, ND. 'Majoret' field peas were planted on 29 Apr, at a rate of 150 lb/acre with a 7.5 inch, 1560 John Deere no-till drill. The herbicides Prowl and Spartan were applied on 29 Apr at rates of 2 pt/acre and 2 oz/acre, respectively. Plots were 10 ft by 30 ft. Treatments were replicated four times in a RCBD. Pre-bloom applications of insecticides were made on 21 Jun. The pre-bloom insecticides included azadirachtin (Aza-Direct, 8.0 fl oz/acre), bifenthrin (Sniper, 6.4 fl oz/acre), and bifenthrin plus imidacloprid (Swagger, 11.0 fl oz/acre, 0.5 lb/gal of each AI). The early pod insecticides were applied on 6 Jul when pods had started to form on approximately half of the field. In addition to the insecticides applied at pre-bloom, Aza-Direct was also applied at the 16.0 fl oz/acre rate and beta-cyfluthrin (Baythroid) was applied at a rate of 3.2 fl oz/acre. Late pod insecticides were applied on 19 Jul. In addition to the insecticides applied at pre-bloom, beta-cyfluthrin (Baythroid) was applied at a rate of 3.2 fl oz/acre. Insecticides were applied using a carbon dioxide propelled back pack sprayer and a hand boom with flat fan nozzles at a volume of approximately 10 gal/acre. Pea aphid populations were assessed by counting the number of aphids on the top 8 inches of 10 pea plants per plot and taking five sweeps per plot with a 15 inch diameter sweep net. Pea aphid counts were taken 1 to 2 d after each of the three applications and 22 d after the pre-bloom and early pod applications. Field peas were senescent and were harvested before the 22 d post late pod evaluation. Data were transformed log (x+1) prior to analysis. Data were analyzed with ANOVA and treatment means were separated using the Tukey's honestly significant difference (HSD) test, P = 0.05.

Comparative Efficacy of Common Active Ingredients in Organic Insecticides Against Difficult to Control Insect Pests

“…Although Entrust provided ineffective GPA control in our trials, several studies show moderate levels of control efficacy ranging from 41% to 64% against several aphid species [ 53 , 54 ]. Field trials testing the control efficacy of pyrethrin combined with azadirachtin against PA generally showed some suppression (<30%) but not enough to provide effective control [ 55 , 56 ]. Our results on PA are consistent with these findings.…”