Apple, Phytotoxic Effects of M-Pede at Three Ph Levels, 1993

Insecticides were applied to mature trees in Fennville, Ml at a rate of 125 gpa with a FMC 1029 airblast sprayer. Treatments were arranged in a completely randomized design of nine tree blocks (including nine different varieties), replicated three times. Applications of all materials were made at petal fall and 4 and 8 cover, on 2 Jun, 20 Jul and 7 Sep. Imidan, Captan, Guthion, Nova, Thiodan, Rubigan, Bayleton, and Streptomycin were applied separately to all treatments. Evaluation of phytotoxicity was made on 22 Jun, 27 Jul, 5 Aug and 13 Sep by randomly selecting 25 leaves and fruit/tree rep. (75 leaves and fruit/variety/treatment). Leaves and fruit were rated on a 1-5 scale, for phytotoxicity where 1 = 0%, 2 = 1-25%, 3 = 26-50%, 4 = 51-75%, and 5 = 76-100% showing injury.