ABSTRACT

On the investigations of anthracnose of pomegranate, survey was caried out during 2023- 24 to asses that disease severity in the northern Karnataka. The results revealed that in Bagalkot district, anthracnose severity was highest, with infection on leaves (28.18%) and on fruits (33.36%), while Vijayapur district reported 19.55 per cent and 23.48 per cent severity on leaves and fruits, respectively. The pomegranate cultivar 'Kesar' exhibited the most severe anthracnose, with on leaves 28.84 per cent and on fruits 34.88 per cent. Morphological analysis of the pathogen revealed septate mycelium, single-celled conidia with oil globules, and cylindrical shaped hyaline conidia borne on conidiophores. The maximum conidial length (17.53 μm) was recorded in isolate Coll-23, significantly longer than other isolates, with the minimum length (8.06 μm) observed in isolate Coll-14. Richards’ agar supported the maximum growth of Colletotrichum gloeosporioides, but the pathogen showed the highest sporulation on PDA media. Molecular characterization of fifteen isolates revealed five C. gloeosporioides, two C. Fragaria, four C. Siamese, and four C. theobromicola species from northern Karnataka.
In vitro fungicide evaluation revealed that chlorothalonil achieved 86.76 per cent inhibition among non-systemic fungicides, while propiconazole 25% EC completely inhibited mycelial growth at all concentrations among systemic fungicides. Additionally, complete mycelial growth inhibition (100%) was recorded with prochloraz 24.4% + tebuconazole 12.1% w/w EW, metiram 55% + pyraclostrobin 5% WG, captan 70% + hexaconazole 5% WP, zineb 68% + hexaconazole 4% WP, carbendazim 12% + mancozeb 63% WP, tricyclazole 18% + mancozeb 62% WP, and carboxin 37.5% + thiram 37.5% DS across all concentrations. Among bio-agents, Trichoderma harzianum was highly effective, inhibiting the mycelial growth of C. gloeosporioides by 85.93 per cent.