Epidemiology and management of bacterial blight of pomegranate caused by Xanthomonas axonopodis pv punicae Hingorani and Singh Vauterin et al

Abstract

Considering the magnitude and resultant losses due to bacterial blight in newlinepomegranate, investigations were undertaken on disease, pathogen, environment and newlinemanagement aspects. Survey revealed the highest disease incidence in Chitradurga, newlineAnantapur and Koppal districts and lowest incidence and severity was recorded in Bellary newlinedistrict. newlineThe bacterium was rod shaped, gram negative and capsulated. It was positive to newlinestarch hydrolysis, gelatin, liquefaction and H2S production. Modified D-5 medium was found newlinesuperior in supporting the growth of the pathogen. Cultural variability among the 20 different newlineisolates revealed the variability in growth and colony characters. The isolates exhibited 100 newlineper cent polymorphism for OPA20, OPB03, OPF07 and OPF10 primers showing significant newlinemolecular variability. Among the different seasons, mrigbahar was found most vulnerable and newlinehastbahar was found relatively safe in avoiding the disease. Rainfall for a longer period, newlinemaximum temperature between 29.4-35.60C and minimum temperature between 19.5 to newline27.30C, RH of 63-87 per cent were found favourable for the disease development and spread. newlinePathogen survived upto 20 to 22 and 18 to 20 weeks in the infected residues buried newlinein sterilized and unsterilized soil conditions, respectively. Neem, tridax and achyranthes were newlinethe alternate hosts for the pathogen. Bordeaux mixture 1% spray was very effective in newlinereducing the initial inoculum of the pathogen. newlineIn vitro and in vivo evaluation of bactericides indicated that bronip (0.05%) + COC newline(0.2%) was highly effective in managing the disease with higher yield levels. newlineIn biological control, Bacillus subtilis, Pseudomonas fluorescens and garlic extract newline(10%) were significantly effective in reducing the disease. Application of multinutrients (1%) newlinerecorded the lower incidence and severity of the disease. The IDM strategy evaluated was newlinefound successful and feasible in managing the disease than farmers method of disease newlinecontrol.