Apple, IGR Timing Trial for Broad Spectrum Insect Control, 1994

Abstract

Abstract Insecticides were applied to mature trees in Fennville, MI (Red Block) at a rate of 100 gpa with a FMC 1029 sprayer. Treatments were arranged as a completely randomized design. Plots consisted of three rows by three trees, each replicated 4 times. Applications were made on 27 May (petal fall), 7 Jun (1C), 20 Jun (2C), 30 Jun (3C), 14 Jul (4C), 21 Jul (5C), 26 Jul (6C), 2 Aug (7C), 8 Aug (8C) and 12 Aug (9C) as indicated in the table. Guthion applications were timed with the CM predictive model of the Neogen Envirocaster. V 71639 applications were timed for first sustained CM flight followed by second app. in 21-28 days, for both CM generations. RH treatments were timed for 150 degree days base 50 after first sustained CM flight, followed by two more applications 10-14 days apart, for both CM generations. In addition, RH treatments received petal fall applications. Captan was applied separately to all treatments. Midseason fruit evaluations were made on 23 Jun by randomly picking 50 apples from the periphery of the center tree from each replicate, for a total of 200 fruit per treatment, and on 14 Jul by similarly picking 25 apples per rep. A harvest fruit evaluation was made on 26 Sep by randomly picking 50 apples from the periphery of the center tree, per replicate or a total of 200 apples per treatment. OBLR terminal evaluations on 13, 20, and 29 Jul consisted of visual inspection of 100 terminals from the center tree of each replicate for presence of live and dead (this category also includes damaged terminals with no larvae present) leafrollers. OFM terminal evaluations on 20 Jul and 29 Jul consisted of visual inspection of 100 terminals from the center tree of each replicate for the presence of flagging damage. STLM evaluations were made on 14 Jun by picking 50 randomly selected leaves from the center tree of each replicate, for a total of 200 leaves per treatment. Damage from STLM sap feeding and tissue feeding stages were distinguished and recorded separately for comparison.