Evaluation of fungicides and bactericides for the control of bacterial leaf spot of processing tomatoes, 2018

摘要

The experiment was conducted at The Ohio State University's North Central Agricultural Research Station in Fremont, OH on Hoytville silty clay loam soil. Tomato 'Peto 696' seeds were hot water-treated (10 min pre-soak at 100°F, soak for 25 min at 122°F) and sown on 10 Apr into 288-cell plug trays containing Metro-Mix 360 seedling mix. On 13 Apr, the test field was plowed. Potassium (300 lb/A K2O), phosphorous (78 lb/A P2O5), nitrogen (108.5 lb/A NH4NO3) and boron (7 lb/A) were incorporated and raised beds were prepared on 5-ft centers on 28 May. The herbicides Dual II Magnum (20 fl oz/A), Sencor (0.33 lb/A) and Compadre (2.8 oz/A) were applied and incorporated into the test field on 31 May. An additional application of the herbicides Matrix (2 oz/A) and Metribuzin (5 oz/A) plus NIS (5.6 fl oz/A) and Compadre (drift control) (2.8 oz/A) was made on 2 Jul. Tomato 'Peto 696' seedlings were transplanted on 1 Jun. Starter fertilizer (N-P-K 10-34-0; 0.7 qt/50 gal water) was applied in the transplant water. Plots were arranged in a randomized complete block design with four replications. Each plot consisted of one row of 25 plants spaced 1 ft apart with 5 ft between rows. Treated rows were alternated with non-treated border rows. Warrior II (1.9 fl oz/A), Asana XL (9.6 fl oz/A), Radiant SC (8.0 fl oz/A) plus LI700 (11.3 fl oz/A) and Mustang Maxx (4 fl oz/A) were applied on 20 Jul; 2 Aug and 14 Sep; 20 Aug; and 31 Aug, respectively. Foliar treatments were applied using a tractor-mounted CO2-pressurizedsprayer (55 psi, 43.6 gal/A, 3 mph) beginning 2 Jul and ending 11 Sep for a total of eleven applications. To prevent early blight and Septoria leaf spot, Bravo Weather Stik 6SC (2 pt/A) was applied 13 and 26 Jul, 13 and 25 Aug and 7 Sep, and Quadris 2.08SC (6.2 fl oz/A) was applied on 20 Jul, 2, 20 and 31 Aug and 14 Sep. The field was cultivated, hand weeded and hoed on 9 and 26 Jul. Plants in treated and non-treated control rows were inoculated with approximately 108 CFU/ml X. perforans strain SM761 (moderately copper resistant) on 12 and 24 Jul using a tractor-mounted CO2-pressurized sprayer. Plants were overhead irrigated with 0.25 in. of water on 17, 24 and 27 Jul. The severity of bacterial leaf spot in each plot (all plants) was evaluated on 2, 9,18, and 25 Aug and 1 and 16 Sep using a scale of 0-100% foliage affected. Fruits were harvested from five plants in the center of each treatment row on 18 Sep; weights of healthy fruit and fruit with bacterial leaf spot, anthracnose, blossom end rot, and minor fungal fruit rots were measured. Average maximum temperatures for 7-30 Jun, Jul, Aug and 1-12 Sep were 80.8, 84.1, 83.1, and 80.4°F; average minimum temperatures were 62.7, 63.2, 64.1, and 64.1°F; and rainfall amounts were 2.3, 1.4, 3.7, and 0.4 in., respectively. Analysis of variance was performed using the GLIMMIX procedure and means were separated by Fisher's least significant difference (FLSD) test using SAS software.