How do you consistently produce a high-quality, high-yield cotton crop? When asked that question, cotton experts surveyed say variety selection is crucial. Here are their thoughts on cultivar choice and other key factors to consider before ever putting a seed in the ground.
“Variety selection is the foundation for developing an effective management plan,” said John Barnett, Louisiana Extension cotton specialist. “Plant only recommended varieties or ones that have yield and performance history.”
Barnett says a key part of the selection process is determining the varieties best-suited for different fields and management plans. “Select varieties, not just a variety. Never put all of your faith or acreage in one variety.”
The specialist also suggests leaving variety testing to the research stations. “There is nothing wrong with planting a limited acreage in an unknown variety for your own information. But when it comes to selecting varieties for the whole farm, go with proven, recommended varieties.”
Barnett says other considerations when selecting a variety include:
- Many of the light-textured (sandy) soils in which cotton is grown in Louisiana are infested with plant pathogenic nematodes and fusarium, the fungus responsible for fusarium wilt. While either pest alone can injure the crop, the combination of these pests can be devastating.
- High micronaire and short staple have been major problems for many Louisiana cotton growers the past three seasons. Micronaire is a measurement of the lint surface area. Measurements above 4.9 or below 3.5 will result in a discount.
Barnett noted that over the last three years, LSU AgCenter evaluations of varieties at statewide research locations have not indicated much high or low mike.
“Most of the problems we see occur under farm conditions. So I think management is a lot of this along with variety selection. However, Don Boquet, (LSU AgCenter research agronomist) has noted a trend toward higher mike at research stations located in the northeast section of Louisiana over the past few years.”
Mississippi Extension cotton specialist Will McCarty stresses that variety selection “is becoming more critical every year. Varieties have the genetic ability to produce fiber quality in a given range. Environment and management can influence which end of the range quality will lie on.”
He noted that in recent years, “yield increases have come with higher mikes — this must be taken into consideration in variety selection.”
According to Jane Dever, cotton breeding and product development manager for Aventis, “A single magic bullet will not answer the question. Cotton production is a natural process, so it is subject to natural variability.”
She suggests reducing risk by selecting varieties that are yield-stable within the area of adaptation. “Many high-quality varieties are later-maturing, and will demonstrate more variability from year to year. Choose varieties that produce well in many situations that also demonstrate genetic potential for good staple, strength and micronaire.”
One thing to remember however: “Varieties with the genetic potential to produce long staple are subject to reductions when hit with severe drought during the fiber elongation period. But varieties that do not have the genetic potential for long staple will not produce longer staple even in the best conditions.”
David Guthrie, director, technical services, Stoneville Pedigreed Seed Co., says growers should focus on planting an assortment of varieties of differing maturities. High-yield potential, proven field performance and acceptable fiber quality are also important considerations.
“The differing maturity enables growers to optimize yield under an array of circumstances,” he said. “Fiber quality in very early to early varieties can be enhanced by a favorable growth environment from early square through four weeks of bloom.
“In contrast — full season varieties are more forgiving of early-season conditions but require a longer period of acceptable conditions to produce superior fiber quality.
“Growers without high-capacity irrigation systems can reduce their risk of lower-quality fiber discounts by relying less on very early varieties and more on mid- to fuller-season varieties.”
Arkansas Extension cotton specialist Bill Robertson says convenience should not compromise variety selection. “To get top yields, use your state and county test results. Include neighboring states results if applicable. To get consistent yields, evaluate yields at various locations and different systems such as comparing rankings in dryland and irrigated.”
To optimize fiber quality, “Evaluate varieties for possible problems. Prepare to manage according to weaknesses.”
Robertson added that more research is needed on cotton fiber quality. “We are looking at an interaction of factors causing the reduced quality we have seen the last couple of years in our cotton fiber. It is a little early now to point fingers, but I hope to evaluate data in the field from our Technology Challenge.
Robertson said that he and University of Arkansas Extension agronomist Gus Lorenz are working with cooperators across the state to compare favorite Bt/RR varieties to top conventional varieties.
“Some cooperators have included a RR variety as well. We will compare the economics from start to finish. Fiber quality will be included. Preliminary data from one producer indicates similar yields in his Bt/RR and conventional cotton; however, the fiber is going into the loan 8-plus cents lower with the Bt/RR variety.”
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