Three-Day Count as a Vigor Test for Cottonseed

The number of strong seedlings in germination tests of acid delinted cottonseed [Gossypium hirsutum (L.) and Gossypium barbadense(L.)] afterthree days at 30°C were compared to cool germination test results. Three comparisons were conducted, two with G. hirsutum L., (30 and 24 seed lots) and one with G. barbadense L., (seven seed lots). In the thirty seed lot comparison with G. hirsutum L., the 3-day count averaged 78.4% and cool germination test averaged 75.3%. Sixty percent of the 30 seed lots had 3-day counts that were ± 7 percentage points of the cool germination test. In the second comparison of twenty four seed lots with G. hirsutum L„ the 3-day count averaged 81.5% and cool germination averaged 81.4%. Ninety-one percent of the seed lots had 3-day counts that were ± 7 percentage points of the cool germination test. In the seven seed lot comparison with G. barbadense L„ the 3day count averaged 81.0% and the cool germination test averaged 79.5%. Six of the seven lots had 3-day counts that were ± 7 percentage points of the cool germination test. These data suggest that counting strong normal seedlings after three days at 30°C may be an acceptable alternative vigor test for cottonseed where facilities and equipment for a cool gemination test are not available.