Evaluation of Late-Season Bactericide Applications to Reduce Xanthomonas hortorum pv. carotae on Harvested Carrot Seed

Series/Report Number: COARC2014

Abstract: and Phyton 27 AG for the suppression of Xanthomonas hortorum pv. carotae (Xhc) on harvested carrot seed. Bactericide applications were made in late August one to two weeks before harvest in each of two fields, and harvested seed from the plots was assayed by plating dilutions of seed washes onto a semi-selective agar medium. Seed assays were conducted in parallel by two labs. A significant (P = 0.0008) reduction in Xhc populations on harvested seed was observed in one of the two fields, but only for seed tested in one of the two labs. In general, both treatments reduced Xhc levels on harvested seed compared to the control plots but not to the extent that would reduce the need for hot water seed treatment.