Field Evaluations of Bacterial Inoculants to Control Seedling Disease Pathogens on Cotton. C. Hagedorn, Department of Plant Pathology, Virginia Polytechnic Institute and State University, Blacksburg 24061. W. D. Gould, Canmet-Emr, and T. R. Bardinelli. Ottawa, Ontario, Canada K1A 0G1; and BASF, Durham, NC 27713. Plant Dis. 77:278-282. Accepted for publication 3 November 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0278.

Through two seasons of field evaluations, selected bacterial strains performed as well as commercial fungicides in repressing seedling disease pathogens (Rhizoctonia solani and Pythium ultimum) on cotton. While certain strains did effectively control seedling disease at several locations, there was a lack of consistency among locations and between years, and the performance of an individual strain could not be related to either disease-pressure estimates or those environmental factors that were measured (soil moisture and temperature). Improved seedling stand counts by the introduced strains were not correlated with improved cotton yields in either year of the tests. For two bacterial strains, both in-furrow granular and in-furrow liquid (spray) inoculants produced plant stands that were superior to those obtained with seed-applied inoculants.