Disease control by experimental fungicides on Golden Delicious, Idared, and York Imperial apples, 2008

摘要

Fifteen experimental, combination, and registered treatment schedules were compared on 8-yr-old trees. The test was conducted in a randomized block design with four replicates separated by non-treated border rows. Test rows served as nontreatedborder rows in 2007 which allowed for more uniform development of mildew inoculum on trees used in this trial. Fungicide treatments were applied to both sides of the tree on each indicated application date with a Swanson Model DA-400airblast sprayer at 100 gal/A as follows: 16 Apr (York, TC, tight cluster; Golden Delicious TC-OC, tight-open cluster; Idared, P, pink); 24 Apr (York, P; Idared, PF, petal fall; Golden Delicious, 50% bloom); 14 May (York, PF; Golden Delicious andIdared fruit set); first- fifth covers (1C-5C): 28 May, 11 Jun, 25 Jun, 11 Jul, 1 Aug. Maintenance applications applied to the entire test block with the same equipment included Asana, oil, Agri-Mycin, Assail, Fruitone L + Sevin XLR, Lannate LV,calcium chloride (Yorks only), Provado, Imidan WSB, Intrepid, and Altacor. Inoculum placed over each Idared test tree included cedar rust galls on 8 Apr, bitter rot mummies and wild blackberry canes with the sooty blotch and flyspeck fungi on30 Apr. Other diseases developed from inoculum naturally present in the test area, including cedar-apple rust inoculum from red cedars in the vicinity. Foliar data are from counts of ten shoots per tree from each of four reps on 16 Jun (GoldenDelicious), 20 Jun (Idared) or 2 Jul (York). Fruit data represent postharvest counts of 25 fruit per replicate tree harvested 22 Sep (Idared), 18 Sep (Golden Delicious), or 8 Oct (York). Percentage data were converted by the square root arcsintransformation for statistical analysis.