Spidermite and Aphid Control in Chemical Trials on Strawberries, 1986

Abstract

Abstract Parker’ strawberries were transplanted early Nov ‘85 into drip-irrigated, double-row raised beds. Beds were mulched with clear plastic approximately 1 wk following transplanting. Treatments were arranged in a randomized complete block design with 4 replicates of each treatment. Each replicate consisted of 2 sub-beds (2 rows by 30 ft). Insecticides were applied on 5 and 19 Mar, 2, 16, and 30 Apr, 14 and 28 May. As foliage height and density increased, nozzles varied from 2-4/row and carrier was 100 gal/acre. Disc-type nozzles incorporated D-2 or D-3 orifice discs, #23 cores, and 50 mesh screens. All treatments except avermectin Bi included 0.04% spreader-sticker (Leaf Act 80A). Spidermite population evaluation was based on percentage of plants infested on the highest trifoliate on each plant for 5 plants/replicate every week (20/treatments/wk). Data were collected weekly from 11 Mar through 2 Jun. Aphid counts were collected at the same time as the spidermite data, but percentage of plants infested was based on the presence or absence of aphids on the oldest trifoliate. Again, 5 randomly selected plants were sampled/replicate every week, yield data were collected by weighing (in grams) and counting all berries from each replicate every week from 11 Mar through 2 Jun.