Kritzman, G., Plant Pathology, ARO, The Volcani Center, Bet Dagan, 50250, Israel
Ben-yephet, Y., Plant Pathology, ARO, The Volcani Center, Bet Dagan, 50250, Israel

Detection and quantitative estimation of Xanthomonas campestris pv. campestris (XCC) from soils were done on Kritzman's selective medium (KSM). The composition of KSM, its selectivity and the recovery of 64 isolates of XCC obtained from Israel, Holland, Taiwan, the USA, and Germany are given in detail. XCC was isolated from soil in Israel 22 months after infected cauliflower residues were incorporated into the soil. Metham-sodium (MES) at 16 ml/kg (32.7% active compound) of air-dried soil killed more than 99.9% and 99% of XCC in soil in laboratory and field tests, respectively. MES applied at this rate via the irrigation system in a field infested with XCC, significantly reduced counts of the pathogen in stems, siliques and seeds, and the incidence of plants with black rot symptoms. The treatment was more successful in reducing disease incidence when applied to the soil at a depth of 30 or 40 cm rather than 20 cm. It is recommended that a seed treatment be combined with fumigation of soil with MES for the production of seeds free of XCC. © 1990 Springer Science + Business Media B.V.