Planting 10-15 percent of your cotton crop very early is risky, especially in west Tennessee. But a University of Tennessee study aims to see if the practice could pay off in better use of labor and equipment and perhaps better fiber quality and yield.
The early planting study, conducted by Owen Gwathmey, associate professor of plant and soil sciences at UT in Jackson, was inspired by a similar one by USDA/ARS crop physiologist Bill Pettigrew, Stoneville, who has completed five years of study on the subject.
The first challenge for any grower considering the practice is west Tennessee's narrow planting window. “Every year is so different so far as opportunities for very early planting in Tennessee,” the researcher said. “In years where we get an early-spring heat wave, we can get a stand. But we also have to have a good seed lot, keep cotton out of the water and take care of some basics on seedling disease.”
The Milan study included four varieties planted on two planting dates this year, April 9 and May 9. The latter falls in the normal planting window for UT recommendations for cotton planting.
Two of the varieties, Seed Source CT-10 and CT-12, were reported to have some cold tolerance, noted Gwathmey. The other two varieties were Paymaster 1218 BG/RR and Stoneville ST 474. “We found that all four varieties came through temperatures in the low 30s at the cotyledonary stage in good shape.
“There were some losses, but as best as we could tell the losses were not due to the direct effects of cold, rather to the indirect results of seedling disease pressure.”
Seed quality is crucial to an early-planting program, noted Gwathmey. “Seed size and planting density are really important in regard to the ability to make it through a rough, cold spring.”
For seed treatment, “we didn't do anything extraordinary this first year,” Gwathmey said. “In the future, we may do some more things as far as seed quality issues are concerned. But this year, we looked for cold germ with minimum standards of 60 percent or higher and for any mechanical damage to the seed. “
Gwathmey then planted five seed per foot of row. “That's higher than average, but we did want to make sure that we weren't underseeding. There were some differences in the seed treatments from the companies and that could have played a role in stand development. And we applied an in-furrow fungicide material for Rhizoctonia and Pythium and an in-furrow insecticide.”
As for insect control, “as we find so many times when there are cool conditions after emergence, we do have to be very careful about thrips. In fact, our threshold goes down as the weather gets colder because the seedlings don't grow through those injuries as fast as they do under normal weather.
“So in addition to the in-furrow insecticide, we oversprayed with a thrips material a couple of times after emergence to make sure they didn't hammer the terminals of these plants as they sat around waiting for some heat units.”
The early approach to planting, “might help producers shift some risk from the end of the season back to the beginning and better distribute their labor,” Gwathmey said.
“The real payoff is when the picker can run in mid-September, you know you're really avoiding a lot of bad weather later.”
Planting early means a higher likelihood that young cotton will be exposed to early season rains, which could end up being very helpful in quality, especially in west Tennessee where most cotton is rain-fed, noted Gwathmey.
“The whole short staple, high micronaire scenario relates to heat and drought. If you can sidestep that, you can go a long way to taking some of your bales out of the discount range.
Still, Gwathmey is far from making recommendations on the practice. “It's going to be an interesting area of research, but we just don't have the data to say what we can do with it in Tennessee yet.”
And there are certain risks, as well as precautions that growers should be aware of.
First, growers shouldn't plant early unless the conditions for planting are favorable. “We want to see at least 3 consecutive days with soil temperatures above 65 F at planting depth, plus a warm 5-day forecast” Gwathmey said. In west Tennessee, there will be years that those conditions may not exist during the early planting window.
And growers should not plant any more than 10-15 percent of their acreage in the early window. “Bill really accentuated this in his study. The most severe downside risk is losing the whole seed investment from losing the stand due to a killing freeze.”
By the time the Milan Field Day rolled around on July 26, the early-planted plots had quite a different look from later-planted cotton. “The April 9 cotton was flowering out the top and getting a big boll load and the May 9 cotton was just at mid-bloom,” Gwathmey said.
By the beginning of August, the early planted plots had speckled bolls. “And all those skips that looked so bad after emergence have disappeared as the plants have grown up and compensated.”
The very early cotton plots were harvested on Sept. 5 while the later planted cotton was still in the field as of mid-September. However, late rainfall appeared to hurt the early cotton in Gwathmey's study.
“The weather was rainy, and/or cloudy and humid the last two weeks of August and through the Labor Day weekend. There was some gray cotton and some hard-lock bolls in there. It's definitely a case of twice-over harvest.
“If the weather clears up this fall, the later-planted may actually do better. But that's this year. The long term average is that September is usually a much wetter month than August.”
Gwathmey will make observations about not only yield and earliness, but also the quality of the cotton picked and varietal response to cold tolerance. The rainy late season also offered the opportunity to look for varietal responses to boll rot.
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