Control of late blight caused by Phytophthora infestans on tomato cultivars using a high tunnel system, 2008

摘要

A high tunnel (model ‘Solo”, Haygrove LTD, UK), 120 x 28.5 ft, was erected near Mount Vernon, WA on a Puget silt loam soil. Seven-wk-old seedlings of six tomato cultivars were transplanted 3 Jun into two randomized blocks (one inside and one outsidethe tunnel). Each block had four replicates of six plants arranged in single-rows, with 36-in. plant spacing and 78-in. row spacing. Organic fertilizer PAR 4 9-3-7 was incorporated into beds prior to planting at 70, 23 and 54 lb of N, P and K/A, respectively. Plants were fertilized weekly with Acadian 1-1-17 (1 lb/A) and Marine Extract Powder & Organic BioLink 6-0-0 (1 gal/A), 23 Jun-9 Sep. A Florida Weave training system was used to stake the plants. Supplemental drip irrigation delivered 0.28 in. water every 7 days to both blocks until 18 Sep; the plants outside received 5.11 in. additional rainfall, 3 Jun-19 Sep. Environmental data were recorded with a Hobo Weather Station (Onset Computer, Bourne, MA) 3 Jun-19 Sep.The average maximum and minimum temperatures inside and outside of the tunnel were 75.2 and 50.3 oF, and 72.8 and 49.2 oF, respectively. Relative humidity and leaf wetness values inside vs. outside the tunnel were 94.3 and 38.5% vs. 96.7 and 89.2%, respectively. Plots were rated weekly for percent late blight, 11 Jun-19 Sep. Percentage ratings were converted to AUDPC (area under disease progress curve) values. All data were normally distributed, and analyzed using analysis of variance (SAS, Cary, NC).