Epidemiology of the Kresek Phase of Bacterial Blight of Rice. P. Ranga Reddy, Division of Plant Pathology, Central Rice Research Institute, Cuttack 753006, India. Susanta K. Mohanty, Division of Plant Pathology, Central Rice Research Institute, Cuttack 753006, India. Plant Dis. 65:578-580. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-578.

The incidence of kresek (wilting) increased with increased concentrations of bacterial inoculum (Xanthomonas campestris pv. oryzae) in rice cultivars Co 33, IR 8, and Taichung Native 1 (TN 1). However, even the lowest concentration of inoculum induced kresek in highly susceptible Co 33, but IR 8 and TN 1 were susceptible only at higher concentrations. Dipping the roots in the inoculum for a minimum of 5 min caused kresek, if the host and the pathogen were compatible. Isolates of X. campestris pv. oryzae from different areas in India varied in ability to induce kresek. Young seedlings were more susceptible than older plants. Ability to induce kresek increased when isolates were passed through host plants but declined with successive transfers on an artificial medium.