Prevalence, isolation and standardization of growth media for Xanthomonas axonopodis pv. citri causing citrus canker

Kinnow mandarin is popular fruit widely grown in Punjab. its nursery and orchard plants are mainly attacked by citrus canker (Xanthomonas axonopodis pv. citri) causing extensive damage. The disease produced symptoms on leaves, twigs, thorns and fruits. The citrus canker incidence in orchard varied from 13.0 to 42.0 per cent and in nurseries it varied from 17.0 to 63.0 per cent in citrus growing areas of Hoshiarpur, Faridkot, Ludhiana and Fazilka districts of Punjab. Based on the cultural and morphological characteristics, the isolated bacterium was round with creamish to yellowish colonies, gram-ve, rod shaped with high motility among the various growth media namely Wakimoto, nutrient agar, Potato sucrose Peptone agar, Yeast extract Peptone dextrose and Calcium Carbonate Agar, Wakimoto growth medium was found to be significantly superior for the growth of the Xac followed by nutrient agar where as Calcium Carbonate was found least effective.