Selecting a cotton variety could be the most important decision a cotton grower makes in a season. And it’s not an easy task. No one can control the weather, but growers can choose varieties with characteristics that best match their fields in typical growing conditions. We spoke with Extension cotton specialists from three Midsouth universities to get their take on what factors they consider key to cotton variety selection.
Obviously, yield potential is the most important factor for growers, and specialists say consistency is key.
“Growers need to look at as much data as they can to make sure that a variety performs consistently across the board,” said Matt Foster, Extension cotton, corn and sorghum specialist with the LSU AgCenter. “That’s why we do cotton variety trials on many different soil types.”
Tyson Raper, Extension cotton specialist with the University of Tennessee Institute of Agriculture agreed that it is better to choose a variety based on yield stability, or the ability to perform at a high level across different environments.
“When we consider yield, we often think about top-end performance, or how that variety performs when everything is perfect,” said Raper. “In the past several years, we have seen several varieties perform at an extremely high level on one field and crash on another. It doesn’t take long for those to fall out of our mix. Instead, we end up planting varieties that are adaptable and stable.”
“Adaptable, yield-stable varieties are often capable of stretching across different soil types, irrigation regimes, and management strategies. Stability is the most important factor, again, in my opinion, since weather really dictates environment.”
Specialists say it’s also important to match the growth characteristics of a variety to soil type and conditions.
“A farmer knows his field better than anybody,” said Brian Pieralisi, Extension cotton specialist with Mississippi State University. “If he has a field that grows a big stalk, and he plants a variety that’s growthy, then he knows from a nitrogen and PGR standpoint that he’ll have to manage that variety intensely. Or, if he has trouble getting the growth he wants, he may want to plant a growthier variety on that soil type.”
“I’m going to base my management decisions based on the growth habits of these plants,” Pieralisi continued. “You’ve got to do your homework. Just as you’re looking at yield, you’ve got to take it one step further and look at growth characteristics of these plants.”
“It seems you can’t really plant by the calendar anymore,” Foster said. “Analyzing the relative maturity groups of different varieties is going to be another important decision.”
“In the upper Midsouth, later maturing varieties (mids or fulls) are occasionally unable to mature due to our short growing season,” said Raper. “However, adaptable mid-maturing varieties can perform very well within our environment if planted early and managed for ‘earliness’. However, year-in and year-out, early or early-mids are more consistent.”
“We actually saw that response during 2020; mid-maturing cultivars which had been performing very well for us weren’t planted early due to weather and didn’t reach their high-end potential due to a cool fall, and early-mids and earlys outperformed mids in our variety trials.”
Where you farm may determine the emphasis placed on a variety’s disease or nematode resistance package.
“Bacterial blight resistance is important in Mississippi,” Pieralisi said. “We’ve seen devastating yield loss potential in susceptible varieties. That’s something to consider especially on a wet year farther south in the state.”
“If nematodes are limiting your yields, we’ve seen some promising results out of some of the nematode resistant varieties,” Pieralisi said. “If you know you have nematodes, root knot and reniform, that could be a very viable option. They perform well across the state.
In the upper Midsouth, disease resistance may not play as large a role in selection.
“Bacterial blight typically only appears in pockets for us late-season and verticillium wilt only showed up in a big way across the region a few years ago,” Raper said. “IF you don’t have a history of these diseases on your farm, having bacterial blight resistance or verticillium wilt resistance would be a great bonus, but it would not drive the decision.”
Fiber quality varies quite a bit in commercial varieties, but specialists said recent data suggests most of the range falls above a ‘discount.’
“A lot of fiber quality is environmentally driven as well as genetically. You might have a history with a variety where you didn’t like the grades you got back or didn’t like the way it picked off the stalk. The same variety in a different location didn’t have that issue. It comes back to knowing your fields,” Pieralisi said. When you’re looking at yield, peer across the line and see how the variety is grading out. The tighter the market is the more you start looking at these things. If you get a couple cent deduction here and there that that can be a big loss.
While the specialists agreed that herbicide traits are still the greatest factor in decision making beyond yield, they see insecticide traits moving up in importance.
“Entomologists across the belt have suggested the two gene Bt technologies are slipping and reported a benefit to the three gene Bt technologies which contain ‘vip,’” Raper said. “The two gene Bt technologies are still providing value and often acceptable levels of control, but may (occasionally) require additional sprays to control bollworms. Fortunately, several varieties with the three gene Bt traits have been able to achieve similar yields as their two gene Bt trait counterparts. I suspect the transition from 2 to 3 Bt gene traits will continue slowly.”
The most current cotton variety trials for Midsouth states can be found online.