Evaluation of products for the control of angular leaf spot in annual strawberry, 2013-14.

摘要

On 16 Oct 2013, bare-root plants from Canada were transplanted into raised beds fumigated with Telone C-35 (300 lb/A). The plants were irrigated by overhead sprinklers during the day for 10 days to aid establishment, then irrigated and fertilized through drip tape. The beds were 28 in. wide on 4-ft centers. Treatments were arranged in a randomized complete block design with four blocks in adjacent beds. The 10-ft long plots contained 14 plants in two staggered rows 12 in. apart with 15 in. in-row plant spacing. Within beds, plots were separated by 3 ft of empty space. Foliar treatments were applied with a CO2 backpack sprayer delivering 100 gal/A at 60 psi through two TeeJet disc-core hollow cone nozzles spaced 12 in. apart on the boom. Two Actigardchemigation treatments were applied through twin drip tapes in 5,450 gal water/A (0.5 gal per ft of bed). The tapes, each 10-ft-long with 12-in.emitter spacing, were placed next to each row of plants in a plot. Treatments were applied weekly from 17 Janto 14 Mar, 2014 (12 times). To suppress fungal diseases, Captan 80WDG was applied weekly with a tractor-mounted hydraulic sprayer in 100 gal/A at 200 psi (1.8 lb/A in Dec and early Jan; 3.0 lb/A from mid-Jan to mid-Mar). Ripe and diseased fruit were harvested twice weekly from 3 Feb to 27 Mar (16 times). Healthy fruit weighing more than 10 g each were counted and weighed to determine marketable yield. Ten plants per plot were evaluated for angular leaf spot (ALS) after the end of the season on Apr 1 -3. The number of dead leaves with ALS and the number of green leaflets more than 10% blighted by ALS were recorded for each plant. Counts of blighted leaflets were divided by three (since each leaf has three leaflets) and added to the number of dead leaves to obtain the total number of leaves/plant damaged by ALS. Yield and disease data were analyzed by two-way ANOVA in SAS.