Seed-specific placement of in-furrow fungicides for control of seedling disease in cotton

Fungicides are often applied as in-furrow sprays during planting to control cotton seedling disease. To be effective, the fungicide product should cover each seed and the surrounding soil, thus forming a zone of protection for each emerging seedling. Traditional practice has been to apply the product as a solid band along the length of the furrow. However, limiting fungicide application to an area near the cottonseed, and minimizing the amount of chemical applied between seeds, could reduce fungicide inputs significantly while maintaining an acceptable level of disease control. To this end, a seed-specific applicator has been developed to apply discrete pulses of liquid chemical to individual seeds and the surrounding soil at planting. The concept of seed-specific fungicide application was evaluated during 2002 and 2003 using side-by-side, field comparisons of seed-specific and conventional applications of PCNB and etridiazole in plots inoculated with Pythium spp. and Rhizoctonia solani. Cotton was planted at 9.8 seeds m(-1), and seed-specific treatments were applied as spray bands 5.1 cm in length such that fungicide savings of 50% were realized where seed-specific applications were implemented. Seedling disease pressure was present in both years of the study. Stands in the untreated plots averaged less than 25% of that in treated plots. Stand counts in all plots receiving an in-furrow fungicide treatment were significantly greater (P = 0.05) than in untreated plots. There were no significant differences in either year among the seed-specific and conventional treatments. In these tests, seed-specific fungicide applications provided seedling disease control comparable to conventional application while reducing fungicide use by 50%. Seed-specific application equipment has potential to help cotton growers reduce input costs and increase production efficiency. (C) 2004 Elsevier Ltd. All rights reserved.