Apple, Evaluation of Experimental Insecticide Ac-303630 24 Sc, 1991

Abstract

Abstract Treatments were applied to 5 tree plots replicated 4 times in a randomized complete block design. The orchard block consisted of'Red Delicious' on Mill planted in 1970 on a 20' by 20' spacing. Sprays were applied with an FMC handgun sprayer using a 5 HP diaphragm pump at 280 psi until run off, with approx. 4 gal of spray applied to each tree. There were 5 treatments in this test; 1) = AC-303630 50.9 g AI/100 gal, 2) = AC-303630 101.8 g AI/100 gal, 3) = AC-303630 203.7 g AI/100 gal, 4) = Standard Program, and 5) = untreated control. The Standard Program consisted of: Pink—Thiodan 50 WP 454 g/100 gal, Petal Fall—Imidan 50 WP 454 g/100 gal + Carzol 92 SP 60 g/ 100 gal, 1st Cover—Imidan 454 g/100 gal, 2nd Cover—Imidan 454 g/100 gal + Lannate 1.8 L 235 ml/100 gal, 3rd Cover—Imidan 454 g/100 gal, 4th Cover— Imidan 454 g/100 gal, 5th Cover—Imidan 454 g/100 gal, and 6th Cover—Imidan 454 g/100 gal. Spray dates for all treatments and conditions were: Pink— 12 Apr 57°F, 2 mph wind & clear, Petal Fall—2 May 62°F, 0-2 mph wind & clear, 1st Cover—20 May 65°F, 0-2 mph wind & clear, 2nd Cover—10 Jun 85°F, 5 mph wind & clear, 3rd Cover—1 Jul 75°F 0-2 mph wind & cloudy, 4th Cover—17 Jul 83°F, 5 mph wind & clear, 5th Cover—6 Aug 75°F, 2-3 mph wind & clear, and 6th Cover—28 Aug 75°F, 0-2 mph wind & clear. All treatments received regular fungicide cover sprays of Captan or Captan + Rubigan. Mite and mite predator counts were done on a weekly basis, with each mite sample consisting of 25 leaves per tree, brushed and counted with a binocular scope. SP counts are reported as a 3 min count per tree. SJS counts were done on 1 Aug, and reported as the number damaged per 100 fruit per tree and as the number of sites present in the 20 maximally infested fruit per tree. AA counts were made on 6 Jun and 14 Jun. Data are reported as average aphis per colony of the 10 maximally infested colonies per tree. STLM, WALH, EAS, and RAA counts were done on 21 May. STLM counts are reported as mines per 3 min count per tree. WALH counts are reported as damaged leaves out of 300 leaves per tree. EAS counts are reported as infestations per 300 fruit. RAA counts are reported as colonies per tree. A post-harvest fruit evaluation was done, using 100 fruit per tree and reported as percent damage by AM, CM, EAS, PC, SJS, TABM/LR, and TPB. A postharvest fruit finish evaluation consisted of 30 fruit per tree. Each fruit was rated on a 0 to 5 scale for percent russet. Values used were as follows: 0 = no russet, I = raised lenticels, 2 = 1-10% russeted, 3 = 11-15% russeted, 4 = 16-50% russeted, and 5 = >51% russeted. Mean values of each replicate were used for calculations. Data were transformed to log(x + 1) for analysis at P = 0.01 except on the 15 Jul mite count where P = 0.05.