Apple, Insecticide Evaluations, 1993

Abstract

Abstract Insecticides were applied to 10 year old ‘Ida Red’ apple trees on MM III rootstocks. Five three row plots were randomly selected and one was assigned to each treatment. The two outside rows served as guard rows. Data were collected from four or five replicate trees randomly selected from the middle rows in each plot. Treatments were applied with a power take off driven FMC (model 252S) sprayer calibrated to deliver 50 gpa (76.62 liters/ha.), a 6x concentration for this orchard. Treatments were applied on 27 Apr, 21 May and 6 Jul. Other insecticide sprays included a delayed dormant spray of superior oil (60 sec.) applied to the control and the Lannate + Guthion plots on 8 Apr. Guthion 35W (2 lb./A) was added to all sprays (including the 6 Jul treatment) on the NTN33893 plot on and after 18 Jun. Other materials used for orchard maintenance are given later in a table. Insect predators were sampled in a three minute visual count per tree. RAA & AA (complex of AA & SA) were counted as number of infested terminals in 10/replicate, or number of infested water sprouts in 10/replicate, or number in 10 terminals/replicate on which the terminal leaf was infested. Tentiform leafminer and WALH data indicate the number of leaf mines or leafhoppers/leaf present when ten leaves/replicate were examined. Mite data were generated using the Henderson McBurnie method of brushing 20-leaf samples from each replicate. Mites and eggs were counted with a binocular microscope. Data were transformed to either log 10x +1 or square root X + .5 for analysis.