Nyolate Seed Treatment of Brassica spp. to Eradicate or Reduce Black Rot Caused by Xanthomonas campestris pv. campestris. G. E. Harman, Department of Horticultural Sciences, New York State Agricultural Experiment Station, Geneva 14456. J. M. Norton, T. E. Stasz, and H. S. Humaydan. Department of Horticultural Sciences, New York State Agricultural Experiment Station, Geneva 14456, and Harris-Moran Seed Co., Salinas, CA 93901. Plant Dis. 71:27-30. Accepted for publication 2 September 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0027.

Nyolate, a material manufactured as a general disinfectant by the Alcide Corporation, has potential as a seed treatment for eradicating seedborne bacteria. Nyolate is provided as two components that are mixed and diluted with water immediately before use. The first component (Nyolate solution A) contains NaClO₂; the second (Nyolate solution B) contains lactic acid, which acts as an activator. Initial experiments were performed with a formulation that contained 1.3% NaClO₂ in solution A and 7.5% lactic acid in solution B. Subsequently, the manufacturer changed to a second formulation containing 2.73% NaClO₂ in solution A and 15.1% lactic acid in solution B. Trials were conducted with seed lots of Brassica species naturally infected with Xanthomonas campestris pv. campestris. In initial experiments with the first formulation, soaking seeds for 30 min with a 1:1:8 (Nyolate A/Nyolate B/water) mixture eradicated the pathogen from the seed lots tested and caused only a low level of phytoxicity. In later experiments with the second formulation, treatment with a mixture containing 10:3:90 (A/B/water) completely eradicated X. c. pv. campestris from most of the seed lots tested and greatly reduced the detectable level of the pathogen in the remaining lots. Treatment with Nyolate at the 10:3:90 concentration did not reduce stands of kale, collards, turnip, cabbage, or Chinese cabbage but did reduce stands of cauliflower and broccoli. Treating seeds at a 20:6:75 concentration reduced emergence of most of the seed lots tested. Nyolate seems to have promise as a alternative to hot-water seed treatment for Brassica spp.