Vol. 10, Issue 2 (2021)

Author(s):
M Kavitha, C Madhumathi and L Ranjith Kumar

Abstract:
Bacterial canker is one of the major constraints for the production of acid lime in Andhra Pradesh. Even though Petlur selection -1 is tolerant to bacterial canker survey reports revealed that every year 30-35% disease severity was noticed and it is up to 60 per cent in the local variety of acid lime. Streptomycin 100ppm with COC 3000 ppm was recommended but in recent years the efficacy of streptomycin (100ppm) was reduced, it may be due to the development of resistance in the canker pathogen to the antibiotic streptomycin (100ppm). Hence we are planned to evaluate the efficacy of two antibiotics like Bactrinol and bacteriomycin on canker severity of acid lime at the farmer's field of petlur village at Venkatagiri mandal for three consecutive years i.e 2013-14, 2014-15 and 2015-16. In this connection, 10 treatments were planned with three replications and for each replication three plants were selected. The antibiotics were used in alone and in combination with copper oxychloride in different concentrations. The data on disease severity was recorded by using a 0-5 scale. Further fruit yield and fruit weight per plant was also recorded. Pooled data of three years revealed that the canker severity was economically low i.e 7.32 per cent on leaves and 6.54 per cent on fruits when bacteriomycin (200ppm) sprayed in combination with copper oxychloride (3000ppm) and it was statistically on par with the treatment of streptomycin (200ppm) + COC (3000ppm) treatment and recorded 7.29 per cent and 6.61 per cent PDI on leaves and fruits respectively. Average yields also higher in these two treatments (2009 and 2038 fruits /plant respectively). Hence we can suggest that the streptomycin bactericide used at 200 ppm with COC for effective management of canker.