Enhancement of seed vigor in aged cotton seeds through hydro-priming and osmotic priming

Abstract:

Leading seed physiologists agree that aging is the single greatest threat to seed lot viability in long-term storage, yet affordable invigoration methods for cotton remain poorly standardised. This research tested hydro-priming (6 h and 12 h soaking in distilled water), osmotic priming with polyethylene glycol (PEG-6000 at −0.5 and −1.0 MPa), and halopriming with 2% KNO₃ on two-year-old cotton (Gossypium hirsutum L., cv. Coker-312) seeds stored under ambient conditions at Tohoku Agricultural College, Sendai, Japan. Germination, vigor index, speed of emergence, root length, and electrical conductivity of seed leachate were measured. Hydro-priming for 12 h gave the best results: germination rose from 54.3% (untreated control) to 81.4%, vigor index from 412 to 843, and leachate conductivity dropped from 1.87 to 1.14 µS cm⁻¹ g⁻¹. PEG at −0.5 MPa ranked second. The findings show that a simple 12-hour water soak can restore much of the vigor lost during storage, offering a practical, zero-cost option for smallholder cotton farmers.