Effect of Sclerotium rolfsii on seed germination and seedling vigor of sunflower hybrids

The present investigation was undertaken to study the effect of collar rot fungus, Sclerotium rolfsii on seed germination and seedling vigour of sunflower hybrids. The experiment was conducted under in vitro conditions at the Department of Seed Science and Technology and Department of Plant Pathology, CCS Haryana Agricultural University. Results revealed that the pathogen significantly reduced the germination, plumule, radicle length, fresh and dry weights of seedlings, thereby observed cumulative reduction in seedling vigour index for all hybrids under both seed and soil inoculation techniques. Seeds treated with thiram 3g/kg seed had higher germination, more seedling length and higher vigour index in comparison to untreated seeds.