On-Farm Evaluation of Seed Biopriming Technology for Enhancing Germination and Seed Yield of Cumin (Cuminum cyminum L.)

Abstract

Cumin (Cuminum cyminum L.) suffers from small seed size, low seed vigour and poor, non-uniform field establishment, which constrains productivity in the arid and semi-arid tracts of Rajasthan. A seed-biopriming technology combining the soaking agent chitosan with a two-strain rhizobacterial consortium (Bacillus paramycoides and Pseudomonas aeruginosa) was earlier standardised and validated at the institute level. To assess its performance under real farming conditions, ten front-line demonstrations (FLDs) were conducted under SCSP on farmers' fields across seven villages of Ajmer district during the 2025 Rabi season. In each demonstration the bioprimed technology and the prevailing farmers' practice (non-bioprimed seed) were raised in adjacent, paired plots on the same field. Biopriming increased mean germination from 70.22% to 82.08% (16.9% gain) and mean seed yield from 426.0 to 516.0 kg ha⁻¹ (21.1% gain); both differences were significant (paired t-test, p < 0.01, n = 10) and every demonstration recorded higher germination and yield than its paired control. The extension gap was 90.0 kg ha⁻¹, the technology gap 12.3 kg ha⁻¹ and the technology index 2.33%, showing that farmers realised almost the full yield potential of the technology. Economic analysis showed that the bioprimed technology, at a marginal additional cost of Rs 900 ha⁻¹, raised the benefit–cost ratio from 2.24 (farmers' practice) to 2.66 and generated an additional net return of Rs 24,297 ha⁻¹, a return of Rs 28 for every rupee invested in biopriming. The on-farm yield advantage (21.1%) closely reproduced the station-level advantage (20.8%), confirming that the technology is robust and transferable. Seed biopriming with chitosan and the B. paramycoides–P. aeruginosa consortium is therefore recommended as a low-cost, profitable and sustainable intervention for improving cumin establishment, yield and farm income.