North Carolina State University Extension Cotton Specialist Dr. Keith Edmisten is often asked “is cotton seed better than it used to be?”
“Well it depends on what you mean by used to be,” Edmisten said at a Jan. 30 Extension cotton meeting in Wilson. “It’s a lot better that it was 50 years ago. One of the reasons cotton seed is better is because these seed companies use a cool germination test to weed out some of the bad seed. Is cotton seed way better than it was five year ago? I would doubt it.”
Edmisten explained that every year cotton seed can be different and every lot of seed can be different.
“Some years if your seed is coming from Arizona and they have a nice fall, the seed quality in general is high for that next year. Some years if the weather is not so good, the seed quality in general is down some. That’s why it’s important to know this cool germination test,” he said.
Cotton seed with a cool germination test rating of less than 50 percent is poor. Edmisten said cotton seed with a less than 50-percent rating will not perform well under marginal conditions, and seed companies likely won’t sell cotton seed with a rating that low
A cool germination rating of 50 to 65 percent is acceptable, but Edmisten said farmers need to use special care if they plant cotton seed with this rating. A rating of 65 to 80 percent is good while a rating greater than 80 percent is superior. Edmisten said farmers should plant seed with a greater than 80 percent cool germination rating, particularly in marginal conditions.
Cotton farmers need to find the cool germination rating of the seed they plan to buy. “Your dealer or distributor probably has this information. If they don’t’, the seed company certainly does if you have a lot number,” Edmisten said.
In addition to cool germinatoin ratings, Edmisten said cotton farmers need to look at seed size when choosing a cotton variety. Larger seeds tend to produce larger plants with more vigor.
“We know what’s best is to have large seed and high cool germ,” Edmisten said. “Your worst choice would be a small seed with a low cool germ.”
N.C. State Extension cotton agronomist Dr. Guy Collins encouraged farmers to understand their yield-limiting factors on a field- by-field basis when selecting a cotton variety. Water, weeds and insects can all be yield limiting factors.
“Be cautious with field observations. Every variety can perform well or poorly. Yield is influenced by small variations in the environment. Evaluate varieties under the same conditions. Stability is the best predictor of performance,” Collins said. “Every variety can win or lose a trial. No variety wins them all. How frequently a variety performs at or near the top determines stability.”
Cotton farmers should evaluate varieties across soils, rainfall patterns, planting dates etc. It is important to “observe multi-location data and multi-year and look at both on-farm trials and N.C. State’s OVT (Official Variety Trial). Collins continues to emphasize the importance of planting more than one variety and to position varieties by environment and under what conditions they will perform best.