| Popis: |
This study was conducted in a 16-yr-old orchard of ‘Rhode Island Greening‘ trees which measured 12 ft wide and 10-16 ft high and were planted 20 by 20 ft. The treatments were replicated 4 times as single-tree plots and arranged in a randomized block design, with each plot surrounded by 4 unsprayed buffer trees. Treatments were applied with a FMC DO 10 handgun sprayer operated at 150 psi. Approximately 3.6 gal of spray solution was applied to each tree as a spray to drip treatment. Treatments were applied at approximately 10, 50 and 90% egg hatch of OBLR 29 Jun, 10 and 24 Jul, respectively. Application of treatments were arranged in 3 different spray schedules: A, 29 Jun and 10 Jul; B, 10 Jul and 24 Jul; and C, 29 Jun, 10 Jul and 24 Jul. Spinosad was compared to a standard commercial treatment, Lorsban 50W (170 g AI per 100 gal applied on schedule C) and an untreated check. On 16 Aug, 100 terminals per plot were assessed for feeding damage caused by the summer generation of OBLR larvae. On 22 Aug, 100 fruit were collected from each plot and assessed for damage caused by larvae. The Spinosad treatments were analyzed separately as a factorial experiment to compare main effects of rate and schedule. |
