Evaluation of experimental and registered cover spray fungicide combinations for disease control on Fuji apple, 2012

摘要

Fourteen experimental and registered treatments involving package-mix fungicides and a standard summer schedule were compared during the mid-season cover spray period on 17-yr-old Fuji trees. The test was conducted in a randomized block design with four single-tree replicates separated by border rows and in-row border trees. No fungicides were applied before the treatment series began 13 Apr. Test treatments were applied to both sides of the tree on each application date with a Swanson Model DA-400 airblast sprayer at 100 gal/A as follows: 13 Apr (Bloom-petal fall); First through 9th covers were applied: 25 Apr, 9 May, 24 May, 6 Jun, 20 Jun, 18 Jul, 2 Aug, and 22 Aug, respectively. All diseases developed from inoculum naturally present in the test area. Fruit data are based on 25-fruit sample per rep harvested 4 Oct and held at ambient temperatures (68-76°F); evaluated 10 Oct, and then re-evaluated for storage rots 1 Nov. Maintenance insecticides applied to the entire test block with the same equipment during the test period included: Asana XL + Oil, Assail, Delegate, Calypso, Altacor, Imidan, Provado, and Lannate LV. Percentage data were converted by the square root arcsin transformation for statistical analysis using Waller-Duncan K-ratio t-test (p=0.05).