Effect of bio-priming and seed coating on seedling establishment of pearl millet under drought

Abstract:

In the sandy loam soils of sub-Himalayan Maradi Region, pearl millet seedlings often fail to emerge when the first post-sowing rain is followed by a dry spell lasting 10-15 days. This research tested whether bio-priming with Trichoderma viride and polymer seed coating with ZnSO₄-enriched carboxymethyl cellulose — applied alone and in combination — could improve seedling establishment under simulated drought. A laboratory germination test under three moisture regimes (well-watered, −0.5 MPa, −1.0 MPa using PEG-6000) and a concurrent field trial during rainy season 2023 were conducted at Maradi. The combined bio-primed-plus-coated treatment raised germination under severe drought (−1.0 MPa) from 34.2% (untreated control) to 72.8%, improved seedling vigour index by 181%, and lifted field emergence at 13 DAS from 52.1% to 82.6%. Bio-priming alone and coating alone produced intermediate results. The combined treatment offers a practical, low-cost pre-sowing intervention for pearl millet growers in drought-prone pockets.