Ali Raza

BACTERIAL LEAF STREAK OF RICE Causal organisms:- Xanthomonas oryzea p.v oryzicola. Symptoms Bacterial leaf streak appear fine water soak translucence interveinal streak on leaf on leaf Surface. The length of streak is 1µ to 10µ they are surrounding by veins. Veins delimited. Early it transparent later become yellow to orange The minute yellow to amber beat on surface of streak which are actually bacterial masses. The abundant of these masses become dry the postulates felt rough on the leaf. The dry beads are disseminated through wind rain splashes. The streaks cloacae with one another form cover the large veins. In case of severe infection the fore leaves with blightened and leaf streak are surrounded by yellow hallow. Disease cycle:- Seed born disease it cannot transmitted through soil debris and weeds. The bacteria hibernate in under glumes of mature seed. First leaf carry bacterium in early part from which the secondary grow is occur. Secondary infection bacteria through natural multiply in parenchyma tissue. Sub natural cavities and inter cellular space in parenchyma and ventilation. These parenchyma replace by bacterial masses. After lesion streaks are formed and on the surface of streaks during night under moisture condition the oozes are formed on leaf surface. Young rice leaf are more susceptible as compared to the mature. 2-3 continues days with high relatively humidity that is 83 or few drop during morning hour necessary for infection. Management:- In the presence of high humidity heavy doses of nitrogen shades and closed planting help in spread of disease. This disease is usually retard with the age of crop When we apply high nitrogen amount in the field in respective of age also favor. Seed must be retained reliable to minimize the seed born inoculum. Soaking of seed in 0.25% streptomycin as dipping the seed in hot water at 52⁰C for 30 minutes and spry vitavax @ 0.15 to 1.3 is effective in preventing the lesion infection.