ALEXANDRIA, La. - We are beginning to get some cottonseed delivered and on farms as we gear up for planting the 2004 crop. Because of history and the large amount of acreage we are likely to plant to full-season varieties, I expect there will be a good deal of cotton planted in early- and mid-April this year. There is no problem with doing that as long as soil temps are adequate (greater than 60 degrees F) and the forecast is favorable. By favorable, we would like to have at least 25 DD-60s forecast to accumulate within five days of planting with little or no chance of a cold rain. Remember, cotton can tolerate some cool conditions and some wet conditions, but the combination of the two can be lethal and result in a replant decision.
One way to hedge your bets when planting extremely early is to check the cool germination of your seed. This information does not appear on the bag, but can be easily obtained from the seed company, or, in some cases, the dealer who sold the seed. The cool germ test is a measure of seed vigor. Obviously higher values are better, but knowing what the cool germ is for all of your cotton is the most important thing. For example, if you know before planting that you have some seed that has an 80-percent cool germ and some that has a 60-percent cool germ, it is advisable to plant the lot with 80-percent cool germ first. The reason is the early planting dates are more likely to encounter some adverse conditions in which greater seed vigor can help obtain an acceptable stand. If lot A has an 80-percent cool germ and lot B has a 60-percent cool germ, there may be a difference in emergence if they are both planted in early April. However, if they are both planted in early May when conditions are more favorable for germination and early growth, there will likely be no difference between the two.
Knowing the cool germ value for the seed lots on your farm is the most important thing. With that knowledge, it can be used as a management tool to obtain a good stand and avoid replanting decisions. There is not a set industry standard for conducting a cool germ test; therefore the results are best if compared only within a list of values from a given company. Cotton seed is more expensive than ever and is actually a delivery mechanism for biotechnology traits, variety genetics and, in many cases, insecticide and fungicide seed treatments. That makes replanting an expensive proposition, not to mention the loss in time. Using all of the available information and taking all the measures you can to obtain a good stand with early-planted cotton are advisable.
Dr. Sandy Stewart is the cotton specialist for the LSU AgCenter.