Assessment of cottonseed deterioration during accelerated ageing

An experiment was carried out using an upland cotton (Gossypium hirsutum L.) cv. NIAB-78 to investigate the physiological and biochemical aspects of seed deterioration during accelerated ageing. The seeds were subjected to 40-44°C and 90-95% relative humidity for 1, 2, 3, 5, 7, 10, 15 and 20 days for artificial ageing. Controlled ageing linearly decreased the germination capacity. There was a complete loss of germination at 20 days of accelerated ageing. The decline in seed germination during accelerated ageing was accompanied with the increase in mean emergence time (MET), days to 50% germination (T₅₀), electrical conductivity (EC) of solute leakage, free fat acidity and lipid peroxidation. Accelerated ageing not only affected emergence percentage and time but also decreased the seedling vigour, as is indicated by reduction in root weight, shoot weight and hypocotyl length. The cottonseed deterioration by accelerated ageing might be due to membrane disintegration and inactivation of enzymatic systems due to lipid peroxidation and increase in free fat acidity.