Evaluating fungicides for controlling early and late blight in tomato, 2009.

摘要

Tomato seedlings of cv. Mountain Fresh Plus were transplanted on 5 Jun into a Howard gravelly loam at the H. C. Thompson Research Farm, Freeville, NY. Treatments were arranged in a randomized complete block design with four replications. Each block consisted of eight plants spaced 22 in. apart within a 15 ft row with 10 ft between each block and 14 ft between each row. Plants were inoculated with 20 ml /plant of a 25,000 spores/ml suspension of the light phenotype isolate 10 of A. tomatophila on 1 Jul. Rainfall (in.) was 4.81, 4.00, 5.83, and 2.37 for Jun, Jul, Aug, and Sep, respectively. Fungicides were applied with a CO2 pressurized boom sprayer at 60 psi, delivering 23 gal/A through four TeeJet XR11003 flat fan nozzles spaced 20 in. apart. Sprayswere applied on a 7-day schedule (22, 29 Jul; 3, 11, 18, 25 Aug; 1, 8 Sep). Foliar defoliation for early blight (EB) and late blight (LB)was assessed using the Horsfall-Barratt rating scale (0-11) and for stem lesions for EB using a 0-5 scale on 7, 14,21, and 28 Aug and 4, 10 Sep. Foliar and stem data were converted using the area under the disease progress curve (AUDPC) model to account for foliar and stem disease which progressed over time. The data were analyzed using one-way ANOVA at P=0.05 and significant differences between means were separated using Fishers LSD at P =0.05.