Field deterioration and deterioration during simulated weathering of cotton seed was studied using four cultivars: CAMD-E, a MAR variety; DPL 15N, a naked seeded type; LA 901, a hardseed experimental strain and Stoneville 213 (STV 213) a commercial variety.

Seeds of LA 901 maintained viability (germination plus hardseed) at 90% of higher during an 80 week field exposure period. viability of seed of the other three cultivars declined from the 90% level to the mid-70% level during this period.

In simulated weathering LA 901 maintained viability of 80 +% during a 14-day period while viability of the other three cultivars declined to 31% to 61%. The rate of water absorption of seed of LA 901 was similar to that of CAMD-E for the first 28 hours while STV 213 and DPL 15N were much higher. During simulated weathering seed moisture contents were significantly lower for LA 901 at 4 and 6 days but were not significantly different for the remainder of the 14-day period. After 14 days simulated weathering LA 901 was significantly higher in viable seed than the other cultivars, followed by STV 213, DPL 15 N and CAMD-E respectively.