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Subject: Plant Pathology × Author: S.T.Yenjerappa × End date: 2009 × Start date: 2009 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Epidemiology and management of bacterial blight of pomegranate caused by Xanthomonas axonopodis pv. punicae (Hingorani and Singh) Vauterin et al.
    (UAS Dharwad, 2009) S.T.Yenjerappa; V.B.Nargund
    Considering the magnitude and resultant losses due to bacterial blight in pomegranate, investigations were undertaken on disease, pathogen, environment and management aspects. Survey revealed the highest disease incidence in Chitradurga, Anantapur and Koppal districts and lowest incidence and severity was recorded in Bellary district. The bacterium was rod shaped, gram negative and capsulated. It was positive to starch hydrolysis, gelatin, liquefaction and H2S production. Modified D-5 medium was found superior in supporting the growth of the pathogen. Cultural variability among the 20 different isolates revealed the variability in growth and colony characters. The isolates exhibited 100 per cent polymorphism for OPA20, OPB03, OPF07 and OPF10 primers showing significant molecular variability. Among the different seasons, mrigbahar was found most vulnerable and hastbahar was found relatively safe in avoiding the disease. Rainfall for a longer period, maximum temperature between 29.4-35.60C and minimum temperature between 19.5 to 27.30C, RH of 63-87 per cent were found favourable for the disease development and spread. Pathogen survived upto 20 to 22 and 18 to 20 weeks in the infected residues buried in sterilized and unsterilized soil conditions, respectively. Neem, tridax and achyranthes were the alternate hosts for the pathogen. Bordeaux mixture 1% spray was very effective in reducing the initial inoculum of the pathogen. In vitro and in vivo evaluation of bactericides indicated that bronip (0.05%) + COC (0.2%) was highly effective in managing the disease with higher yield levels. In biological control, Bacillus subtilis, Pseudomonas fluorescens and garlic extract (10%) were significantly effective in reducing the disease. Application of multinutrients (1%) recorded the lower incidence and severity of the disease. The IDM strategy evaluated was found successful and feasible in managing the disease than farmers’ method of disease control.