Temik 15G Evaluated with Selected Fungicides and Pythium Inoculum Alone and in Combination, 1995

Abstract

Abstract Granular in-furrow applications of Temik 15G were evaluated for control of seedling diseases with Terraclor Super-X, Terraclor, Terrazole, and Ridomil fungicides. The test was conducted at the Northeast Research Station, St. Joseph, LA. Plots were replicated 4 times in a RCB design and were 4 rows wide (40-inch spacing) X 65 ft. ‘Stoneville LA 887’ cotton seed was planted 17 Apr on a commerce silt loam soil which was sidedressed with 90 lb N/acre. Cotton seed was planted with a John Deere model 7100 series planter which was equipped with 10 inch seed cones mounted to replace the seed hoppers. The seeding rate was 4 seed/row ft and all plots received 0.5 lb (AI)/acre of Temik 15G. Granular in-furrow treatments and Pythium inoculum were applied with 8 inch belt cone applicators mounted to replace the standard granular applicators. In-furrow spray treatments were applied with a CO2 charged spray system through 25015 flat fan nozzles positioned in front of the press wheels. The spray tips were turned to spray across the furrow and were calibrated to deliver 5 gpa. Stand density was measured by counting all plants in a 10 ft section of an inside row on 5 May and all plants on the center 2 rows on 5 and 24 May. On 9 May, cotton seedling height and disease ratings were made on hypocotyls and roots by evaluating 5 randomly selected plants. In general, stem injury was caused by the fungal disease, Rhizoctonia solani. A rating system of 1 for no visible lesions, 2 for non-girdling lesions, and 3 for lesions that girdled the entire stem was used for stem injury. For root decay ratings (Pythium spp. symptoms) a scale of 1 to 6 was used (1 showing no visible symptoms and 6 showing 100% death of the root system). Pest control was initiated in Jun and continued on an “as needed” basis through Aug. Plots were harvested on 11 Sep. All 4 rows of the plots were mechanically harvested using a John Deere spindle type picker. Yields were converted to lb seed cotton/acre.