Shoot blight suppression, summer disease control, and fruit finish by post-bloom applications on Gala apple, 2014

摘要

Five treatments were compared for shoot blight suppression, summer disease control and fruit finish effects on 13-yr-old Gala/M.26 trees. The test was conducted in a randomized block design with four single-tree replicates separated in the row by border trees. No fungicides were applied before the treatment series began at petal fall. Treatments were applied dilute to run-off: 12 May (PF, petal fall); 1st-8th covers, (1C-8C): 19 May, 28 May, 9 Jun, 23 Jun, 7 Jul, 21 Jul, 4 Aug, and 21 Aug. The inoculation approach in this shoot blight test was to inoculate three actively-growing shoot tips near the top of each test tree to favor secondary spread under the treatment series. Three shoot tips per tree were inoculated 9 May 2014 by dipping scissors in asuspension containing 1X106 streptomycin-sensitive E. amylovora cells/ml, then cutting across the shoot tip. All other diseases developed from inoculum naturally present in the test area. Shoot blight strikes were counted 25 Jun. Fruit data are based on25-fruit sample per rep harvested from each of four single-tree reps 4 Sep. Harvested fruit were stored at ambient warm temperatures through the evaluation process, with initial fruit evaluation 11 Sep, and final evaluation for storage rots after 18 days incubation at ambient temperatures 58-86°F. Maintenance materials applied to the entire test block with a commercial airblast sprayer during the test period included: Admire Pro, Altacor, Assail, Asana XL, BioCover MLT, Calypso, Delegate, Imidan, Lannate LV, and Provado.