Influence of seed priming on the development of pearl millet downy mildew (Sclerospora graminicola)

Pearl millet is a major cereal and fodder crop and prone to attack by Sclerospora graminicola causing downy mildew. The effect of priming for the control of downy mildew using biocontrol agents viz. Trichoderma viride, Pseudomonas fluorescens and Bacillus subtilis and two aqueous plant extracts Melia azedarach and Azadirachta indica was evaluated in two consecutive Kharif seasons in 2016 and 2017. Treatments consisted of seeds bio-primed with P. fluorescens, B. subtilis and T. viride; hydro-primed with plant extracts; chemo-primed with fungicide (mancozeb 64% + metalaxyl 4%) and control as hydro-primed and non-primed seeds. Priming of seeds with biocontrol agents resulted in improved seed germination and vigorous root and shoot growth of pearl millet in vitro. Maximum seed germination and seedling vigour index was provided by seeds primed with M. azedarach extract (93.14% and 1659.48). Bio-priming of seeds with B. subtilis and its foliar application was found most effectual treatment for controlling downy mildew.