We’ve been getting a few questions about how to best utilize cool germ for making planting decisions. As mentioned in several previous articles, growers should utilize the NCDA&CS Cotton Seed Quality Testing Program to document their warm and cool germ for every lot of seed purchased. Additional, growers should utilize the Cotton Planting Conditions Calculator to see the current planting conditions ratings for the 5-Day forecast.

Results from the cool germ test can be more variable than the warm germ test, across seed samples and over time. The cool germ test includes a qualifier (radicle length of 4 cm) in order for germinated seed to be counted, whereas the warm test counts seed as germinated or not. There are other reasons for the higher variability of the cool test that we will not discuss here, but it is important to understand that the cool test is not as consistent as the warm test.