Anil Kumar* & Priyanka Chatterjee
Department of Botany, Ranchi College, Ranchi
Received 11th January, 2011; Revised 26th February, 2011
Abstract : Bacterial leaf blight caused by Xanthomonas campestris pv oryzae (Ishiyama) Dye is one of the important bacterial diseases on rice. This disease causes typical symptoms on infected rice such as leaf blight which appears on leaves of young plants, after planting out, as pale-green to grey and green water soaked lesion near the tip as well as margins of leaf.
For the estimation of susceptible and resistant variety of rice cultivars and percent disease index is essential to calculate the severity of this disease.
In this study, the symptomatically study of four cultivars of rice are IR – 64, KRH-2, MTU-7029 & Lalat was done and also assessment of percent disease index of all cultivars of rice caused by Xanthomonas campestris pv oryzae was carried out.
The symptom expressions were generally similar in all four cultivars. In early stage pale green to light brown spots appeared near the tip and margin of the leaf. Water soaking lesions are present on the young plant and later on water soaking lesions disappeared.
At overall observations, the percent disease index (P.D.I.) value shows that “Lalat” among rice cultivars was more susceptible than KRH-2, MTU-7029, and IR-64. In Lalat cultivar the P.D.I. value rose from 6 percentages to 80.25 percentage and inIR-64 cultivar the P.D.I. value rose from 9 percentages to 70 percentages during 60 days.