Vol. 12, Issue 2 (2023)

Citrus canker caused by Xanthomonas axonopodis pv. citri is an endemic disease of the Acid lime (Citrus aurantifolia) that causes significant quantity and quality losses. In India, citrus is third largest fruit crop cultivated after Banana and Mango. Detailed investigations on various aspects were carried out in the present study. The citrus showing typical characteristic symptoms of leaves, twigs and fruits were collected from Horticulture section, College of Agriculture, Dhule. The disease originally emerged as little, watery translucent spots that were yellow in colour on the foliage and fruits. Crater-like lesions appeared on the surface of the fruit at the severe stage. Young twigs have spots similar to those found on leaves. Thorns have crater-like lesions as well. Twig dieback led to widespread tree decline in the severe stage. The pathogen was isolated by standard tissue isolation method and purified by streak method. Pathogenicity of Xanthomonas axonopodis pv. citri was proved by following Koch’s postulates. The test that used inoculums by syringe inoculation method on plants with Sai Sarbati cultivar in pot culture under green house conditions. Cultural characteristics viz., Colour, size, shape, elevations, margin, texture and surface appearance of different media viz; YNA, PSPA, SA, NSA, YGCA and NA. were studied using on Sai Sarbati cultiver. Among the six media examined, Nutrient Agar medium promoted the most pathogen development. In vitro evaluation of chemicals by paper disc diffusion method revealed that streptocycline 100 ppm + copper oxychloride 0.25% was found most effective for controlling Xanthomonas axonopodis pv. citri by forming 22.74 mm inhibition zone. followed by Kasugamycin + Copper Oxychloride 100 ppm + 0.25% (20.64 mm), Kasugamycin 100 ppm (9.36 mm) is least effective.