Sevin XLR Plus Block Treatment, 1994

A treatment which included Sevin XLR PLUS, and a standard treatment, was each applied to a 1/4 acre block (five rows × five trees/row) of 14-yr-old trees on MM. 106 rootstock. Trees measured 19.5 ft in height and 19 ft in width and were planted at a spacing of 18 × 24 ft. Insecticides were applied as complete sprays to both sides of the tree with a Swanson DA500A airblast sprayer, which traveled at 2.3 mph and delivered a spray volume of 100 gpa. Dates of application were 6 May (petal fall [PF]), 24 May (first cover [1C]), 8 Jun (second cover [2C]), 23 Jun (third cover [3C]), 7 Jul (fourth cover [4C]), 21 Jul (fifth cover [5CJ), 4 Aug (sixth cover [6C]), 18 Aug (seventh cover [7C]), and 1 Sep (eighth cover f8CJ). Other materials applied separately to both treatments and an untreated plot during this experiment were Captan, Kocide, Nova, Penncozeb, Rubigan, Streptomycin, Topsin-M, and Ziram. Treatment effect was determined by counting insects on the periphery of four single-tree ‘Delicious’ replications in the center two rows of each block. Effect of treatments against STLM was determined by counting tissue-feeding mines observed during a 5 min period. Control of RLH and WALH was evaluated by counting nymphs on the underside of 25 leaves per tree. Control of fruit-feeding insects was determined on ‘Delicious’ by scoring 100 picked apples per replication plus up to 100 drop apples per replication for injury on 26 Sep.