Evaluation of fungicides for control of downy mildew of cabbage, Sampson County 2007.

摘要

The experiment was conducted in a commercial cabbage field near Clinton, NC (N35deg 03.332’; W078deg 17.417’). Cabbage was seeded in the greenhouse on 21 Dec 06 and transplanted in the field on 19 Feb. No irrigation was used. Treatments were randomized into four complete blocks. Plots were bare ground, single-bedded rows, spaced at 42 in., 15 ft long with 5- ft fallow borders on each end and non-treated guard rows on each side. Fungicide treatments were applied using a CO2-pressurized sprayer equipped with a single-nozzle, handheld boom with a hollow cone nozzle (TXVS-26) delivering 40 gal/A at 45 psi. Applications were made on a 7-day interval: 30 Mar, 5, 13, 20, 27 Apr and 4 and 10 May. Downy mildew severity was evaluated on 27 Apr, 3 and 11 May. Disease severity was assessed as the number of leaves per plant with downy mildew lesions. Harvest data was taken on 18 and 22 May as the number of marketable heads per plot.