Evaluation of products for the control of bacterial leaf spot of processing tomatoes, 2014

摘要

The experiment was conducted at the Ohio Agricultural Research and Development Center's North Central Agricultural Research Station in Fremont, OH on Colwood loamy fine sandy soil. On 21 Apr the test field was cultivated and disked. Tomato ('Peto 696') seeds were hot water-treated (10 min pre-soak at 100 F followed by 25 min at 122 F, then 5 min in cold tap water) and sown on 14 Apr into 288-cell plug trays containing Metro-Mix 360 seedling mix. On 8 May potassium (240 lb/A K2O), phosphorous (104 lb/A P2O5), nitrogen (114 lb/A NH4NO3) and borate (7 lb/A) were incorporated and on 9 May raised beds were prepared on 5 ft centers. The herbicides Dual II Magnum (1.3 pt/A) and Dimetric 75DF (0.33 lb/A) were applied and incorporated into the test field on14 May; on 29 Jun Sencor DF (0.33 lb/A) was applied by broadcast. Tomato seedlings were transplanted on 22 May. 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 25 plants spaced 1 ft apart with 5 ft between rows. Treated rows were alternated with non-treated border rows. The insecticides Warrior II with Zeon Technology (1.9 fl oz/A), Capture LFR (5 fl oz/A), Coragen~R Insect Control (5 fl oz/A) and Lannate LV (48 fl oz/A) were applied on 12 Jun; 5 Jul; 18 Jul and 1 Aug; and 15 Aug, respectively. Treatments were applied using a tractor-mounted CO2-pressurized sprayer (55 psi, 44.9 gal/A, 3 mph) beginning on23 Jun and ending on 22 Aug for a total of nine applications. The field was cultivated on 16 Jun and hand weeded and hoed on 9 Jun and 15 Jul. Plants in treated and non-treated control rows were inoculated with approximately 108 CFU/ml copper sensitiveX. euvesicatoria strains 767 and 110c, on 27 Jun using a backpack CO2-pressurized sprayer. The severity of bacterial leaf spot was evaluated on 9, 16, 24 and 31 Jul, 7, 14, and 21 Aug, using a scale of 0-100% foliage affected, and the Area Under the Disease Progress Curve (AUDPC) was calculated. Fruits were harvested from five plants in the center of each treatment and control row on 28 Aug; weights of healthy fruit and fruit with bacterial spot, anthracnose, blossom end rot, and minor fungal fruit rotswere measured. Average maximum temperatures for 22-31 May, Jun, Jul and 1-28 Aug were 77.9, 81.5, 79.2 and 80.6°F; average minimum temperatures were 56.0, 61.5, 58.6, and 60.2°F; and rainfall amounts were 0.68, 4.0, 2.4 and 1.1 in., respectively. Analysis of variance was performed using the GLIMMIX procedure and means were separated by Fisher's least significant difference test with SAS software.