Preliminary Insecticide Test on Apple, 1997

Abstract

Abstract Dilute sprays were applied with a hand sprayer (450 psi) at pink (8 May), petal fall (2 Jun), and as cover sprays on 11 Jun, 24 Jun, 8 Jul, 22 Jul, 4 Aug, and 18 Aug. Treatments of the standard compounds Guthion and Lorsban were applied at pink, petal fall, and during the first through sixth cover sprays. Treatments of CM-007 alone and in combination with Silwet were applied at petal fall. DPX-MP062 30 WG (0.35 oz AI/100 gal) and (0.59 oz (AI)/100 gal) was applied at pink, petal fall, and during the 1st through 6th cover sprays. A mixture of DPX-MP062 30 WG (0.35 oz (AI)/100 gal) and Lorsban 50 W (5.3 oz (AI)/100 gal) was also applied at pink, petal fall, and 1C-6C. Agri-Mek 0.15 EC (0.05 oz (AI)/100 gal) and (0.10 oz (AI)/100 gal) was combined with oil (0.125%) and applied at first hatch of the first generation of CM (ca. 1C). After the initial treatment with Agri-Mek 0.15 EC, Guthion 50 W (4.0 oz (AI)/100 gal) was applied at 3C-6C. Treatments were replicated 3 times on single-tree plots (2 ‘McIntosh’ trees and 1 '‘Cortland’) and arranged in a RCB design. Damage from the first generation of CM was estimated by sampling 100 apples on each tree in each replication on 7 Jul. At harvest (8-10 Sep), 100 apples were collected from each tree in each replication and examined for in-sect damage. ERM and predaceous mites were sampled on 25 randomly selected leaves/replication on 21 Jul. The 1st generation of WALH was counted on 25 randomly selected fruit cluster spur leaves on 12 Jun and the second generation was counted on 50 randomly selected spur leaves on 28 Aug. First generation STLM tissue mines were counted on 25 fruit clusters from the trees in each replication on 11 Jul. Second generation STLM tissue mines were counted on 8-10 distal leaves on 20 randomly selected “hardened off” terminals/replication on 28 Aug. Foliar pest counts were transformed Logn (x + 1) and percentages of damaged and clean fruit were transformed Arcsin (Sqrt x) prior to analysis. Treatments means were subjected to a Fisher’s Protected LSD Test (P ≤ 0.05).