Hot Acidified Cupric Acetate Soaks for Eradication of Xanthomonas campestris from Crucifer Seeds.

Acidified cupric acetate soaks were tested for eradication of Xanthomonas campestris from naturally infected crucifer seeds. The pathogen was eradicated from seeds by soaking in 0.5% cupric acetate dissolved in 0.005 N acetic acid for 20 min at 35, 40, 45, and 50 degrees C but not 25 degrees C. Moreover, normal bacterial flora of crucifer seeds and the seed-borne Phoma lingam and Alternaria spp. were reduced by 95, 92, and 81%, respectively, after the cupric acetate treatment at 40 degrees C. The seed germination percentage was generally reduced, but the amount of reduction depended upon the treatment temperature and plant cultivar. At 50 degrees C, less than 50% of the seed of all 12 cultivars tested germinated, whereas at 40 degrees C more than 50% of the seeds of most cultivars germinated. Treating seeds in cupric acetate at 40 degrees C should prove useful for eradicating X. campestris from seeds of breeding lines and stock seed used for hybrid seed production. Furthermore, a significant reduction in total bacterial flora and seed-borne fungi suggests the usefulness of the treatment for other microorganisms associated with other seeds or foodstuffs.