Abstract

Bacterial leaf blight caused by Xanthomonas oryzae (Uyeda and Ishiyama) was reported from India in 1951 from Khopoli area of Bombay. Sulaiman and Ahamed (1955) reported that this disease has caused consideable loss to paddy crop in several parts of Punjab, Uttar Pradesh, Bihar, Orissa, Madhya Pradesh, Maharasthra and Andhra Pradesh in recent years. In Tamil Nadu this disease appeared in the newly introduced high yielding variety Taichung Native 1 in a serious form. This disease was also noticed in some of the improved rice strains under cultivation in Tamil Nadu viz., ADT 27, CO 25, CO 29, CO 30, CO 32 and BAM 3. Srivastava and Rao (1964) reported that seed-borne infection of X. oryzae can be eradicated to the extent of 95-100% by soaking infected paddy seeds for 12 hours at room temperature in aqueous solutions of Agrimycin + wettable ceresan (in concentrations of 0.025+0.05%) followed by hot water treatment at 52-54°C for 30 minutes. With a view to assess the efficacy of hot water and chemical treatments alone and in combination in the control of primary infection of seed, studies were undertaken.

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