Luna Tranquility fungicide combinations for management of potato early blight, 2013

摘要

Research plots were located at the University of Wyoming Sustainable Agricultural Research and Extension Center near Lingle, WY. The soil type was a clay loam and the field plot received overhead irrigation as needed. Four fungicide programs were evaluated for the management of early blight and compared to a non-treated check. On 22 May, seed-pieces were planted in 10-in. spacing with 36-in. row centers. After plant emergence, a randomized complete block design with four replicates was established. Each treatment plot was 20-ft long and four rows wide with a 5-ft non-treated in-row buffer between plots. The field plot area was treated on 24 May with Gly Star (28 fl oz/A) and pre-emergence herbicides Dual Magnum II (1.33 pt /A) and Prowl 3.3EC (1.5 pt /A). All treatments were made to, and all data were collected from, the center two rows. On 6 Aug (after irrigation), Alternaria solani conidia and hyphae (3.65 x 104 spores/ml) harvested from culture plates were applied along the length of two treatedrows of each plot (20 ft). In addition, the 5 ft in-row buffers were also inoculated. Foliar fungicide treatments were applied at ca. 11-14 day intervals, with treatment applications made on 18 Jul; 1, 12 and 26 Aug. Early blight disease severity was measured by calculating the average number of lesions per leaflet. Six leaves were randomly selected from each treatment plot; two leaves each from the top, middle, and bottom third of the canopy. The number of lesions was counted on up to seven leaflets from each of the six leaves. Leaves were collected on 1, 8, 22, and 26 Aug and 5 Sep. These data were used to calculate an area under the disease progress curve (AUDPC) rating for each treatment program. Two rows by 10 ft were harvested with a mechanicallifter on 26 Sep. All data were analyzed with ANOVA. Portions of the data are presented below.