Evaluation of products for controlling angular leaf spot in annual strawberry, 2016-2017

摘要

On 13 Oct 2016, bare-root transplants from Canada were planted in plastic-mulched 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 a central drip tape. The beds were 28 in. wide on 4-ft centers. In early Nov, selected plants were removed from the beds to form individual plots separated by 2- to 4-ft spaces. The plots were 8 ft long and contained 14 plants in two staggered rows 12 in. apart with 15 in. in-row spacing. Treatments were arranged in a randomized complete block design with four adjacent beds as blocks. Treatments were applied weekly as foliar sprays from 4 Nov to 16 Feb (15 applications) with three exceptions. Protone and Quintec were applied before expected rain events (four applications), with three clustered in Feb. Foliar applications were made 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. One Actigard treatment was applied initially as foliar sprays (4 times), followed by weekly applications through twin dedicated drip tapes in 5,450 gal water/A (0.5 gal per ft of bed). The tapes, each 8 ft-long with 12-in. emitter spacing, were placed next to each row of plants in a plot. 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 toearly Mar). Fruit were harvested and graded twice weekly from 12 Dec to 9 Mar (25 times). Marketable, diseased, and total fruit numbers were determined. In mid-Mar, 10 plants per plot were evaluated for angular leaf spot (ALS) by counting the number ofdiseased leaflets per plant. Leaflets that were blighted or mass spotted were considered diseased. Yield and disease incidence data were analyzed by ANOVA in SAS, using Proc GLM procedure (a = 0.05).