ABSTRACT

Dragon fruit is a exotic fruit crop (Hylocereus spp.) introduced to India in late 90’s in Karnataka 2017. Anthracnose in dragon fruit caused by Colletotrichum gloeosporioides survey on disease indicated Vijayapur district (22.47%) recorded average maximum disease incidence than Bagalakote district (21.74%) amongst both district Devarahipparagi taluk Ingalagi village recorded maximum disease incidence of (26.39%) on stems and (25.57%) fruits.
The anthracnose infected stem and fruits characterized by reddish to dark brown lesions with yellow halos. Total six isolates were collected, produced white to whitish grey colony color with regular margin with slightly fluffy to fluffy texture. The colony radial growth was maximum in Potato dextrose agar (88.22mm) whereas Richard’s agar had excellent sporulation (++++). All six isolates produced asexual spores single celled, hyaline, aseptate, cylindrical with rounded ends with oil globule. The conidial size ranges from 11.64 -15.23 µm length and 3.79-5.54µm width. Molecular characterization of six isolates was done through amplification of ITS regions of rDNA producing 650bp amplicons. All six isolates were confirmed as Colletotrichum gleosporioides and obtained accession numbers by submitting sequences in NCBI.
In in-vitro evaluation of combi-fungicides against Colletotrichum gloeosporioides zamir (prochloraz 24.4% + tebuconazole 12.1%) 36.5% Ew and lustre (flusilazole 12.5%+carbendazim 25%) 37.5%SE showed (100%) maximum mean inhibition of mycelial growth at 1000ppm, 1500ppm, 2000ppm concentrations. Similarly in systemic fungicides folicur tebuconazole 25.9% EC showed (98.35%) maximum mean inhibition of mycelial growth at 500ppm, 1000ppm, 1500ppm concentrations. In in-vivo condition zamir (prochloraz 24.4% + tebuconazole 12.1%) 36.5% w/w EW at 1ml/l found to be effective in reducing disease severity after 1st spray (17.31%) and after 2nd spray (14.47%) at fifteen days of interval. Among bio-agents Pseudomonas fluorescens at 10g/l found to be effective in reducing disease severity after 1st spray (25.68%) and after 2nd spray (24.23%) at fifteen days of interval.