Induction and prevention of chilling injury to radicle tips of imbibing cottonseed.

Cottonseed exposed to a temperature of 5 degrees during hydration are killed, or the subsequent germination performance of surviving seed is seriously inhibited. Exposure to chilling for periods as short as 30 minutes reduces germination speed and induces root abnormalities, while chilling for 12 hours may kill all seed. Sensitivity to chilling persists during the initial 2 to 4 hours of hydration. Seeds imbibed 4 hours at 31 degrees , then dried, retain immunity to chilling. An irreversible event that is blocked or disrupted by chilling apparently occurs during early seed hydration.