West Tennessee Extension agents are often posed the same question: What's the latest possible date cotton farmers can plant?
After exceptionally successful late-blooming yields in each of the last three years, many farmers consider agents' general recommendation that planting occur between April 20 and May 10 off the mark.
So Chism Craig, Extension agent with the University of Tennessee, and co-workers conducted variety test trials with three different planting dates: in late April, mid-May and June.
The results revealed “tremendous” yield differences, according to Chism, speaking at the 2005 Cotton Focus meeting in Jackson, Tenn.
“In late April, mid-May and early June, we see a stair-step decline in yield with each successive planting date,” he said.
Chism said the atypical void of a dry period or an October killing freeze in each of the past few seasons was likely responsible for late-blooming ample cotton growth for west Tennessee farmers.
But, he cautioned against relying on that trend to continue.
“It seems like every now and then we revisit the question: Can we plant cotton later than May 10?” he said. “We have had a lot of success the last three years planting cotton late, but I think the law of averages will catch up with us on that.”
Chism said the “biggest story” from field test results concerned loan value. He said there was almost a 6-cent higher loan value for cotton planted in April versus cotton planted in June.
He attributed that difference mainly to color grade quality.
He said that while tests showed some “subtle” differences in density, they were not as dramatic as the yield differences. And fiber quality, he said, was difficult to judge fairly thanks to the unusual heavy rainfall the region experienced in October and early November.
Another common question agents receive, he said, pertains to the number of seeds planted per foot.
“Is one plant a foot in April better than three plants per foot in June? It was this year,” Chism said. “This year, I would have kept one plant per foot. As long as there are not tremendous skips, I think it's better to keep an April-planted stand. That is not to say we are not going to luck out in June planting three plants per foot.”
Chism said field tests show minor characteristic differences between planting one cottonseed per every foot versus five seeds per every foot.
“(In planting one seed per foot) You see a delay in maturity, you are looking at three to four days longer to reach cutout. It's longer for the cracked boll to open,” he said.
But, Chism said, with one plant per foot, the grower doesn't need as many pickings and the plants tend to grow shorter and wider rather than taller. That difference can result in less aggressive chemical applications toward controlling plant height.
Chism said a cotton grower's planting guide and other helpful information is available online at www.Utcrops.com 
He urged growers in the audience to follow a safe, less risky philosophy in regards to planting schedules. “I understand that circumstances come up when you must plant later, but as long as we are planting only a small percentage of our cotton after May 20 — if we don't have all those eggs in that one late-planting basket — I think we'll come out OK,” he said.
“Do everything right the first time to try and insure you get a stand. Because planting is so expensive, treat those seeds with kid gloves. Do everything to make sure it gets the best head start possible.
“It's quite likely the most important thing we do.”
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