p Mycoflora impact on germination and vigour of bottle gourd (Lagenaria siceraria) seeds and its management through different plant protectants

Bottle gourd is an important cucurbitaceous crop. The impact of 14 species from eight fungal genera on bottle gourd seeds was studied through in vitro tests. Bottle gourd seeds were inoculated with each isolate separately and subjected to various germination tests. Maximum germination inhibition was upto 69.3% due to Fusarium proliferatum. Inoculation of seeds with F. proliferatum significantly reduced the germination speed index to 2.69. The seedling vigour index I for seeds inoculated with F. proliferatum and F. incarnation-equiseti (species complex) was 860 and 861, respectively, significantly different from that of non-inoculated seeds having a vigour index of 1791. The seedling vigour index II of seeds inoculated with F. proliferatum was 1818, significantly lower than the control (4631), indicating that the F. proliferatum isolate was highly virulent among all the isolates. Amongst seven plant protectants evaluated for their efficacy as seed dressers against F. proliferatum, propioconazole (25% EC), copper oxychloride (50% WP) and Mancozeb (75% WP) were effective in reducing infection. Germination percentage was highest for seeds treated with the bioagent Trichoderma harzianum 1% WP.