A 34 PLANT per foot of row spacing is desirable for cotton in the Southeast

A 3-4 PLANT per foot of row spacing is desirable for cotton in the Southeast.

Replanting skippy cotton stand a dollars, cents decision

• Lack of moisture is likely to push back planting dates for some cotton growers and will just as likely put some in the undesirable position of deciding whether or not to replant a crop because of large skips in their stand.  

The 2012 cotton planting season is setting up weather-wise to be similar to 2011.

A strong La Niña weather pattern has been in place over the winter months and is expected to last well into the spring of 2012.

Lack of moisture is likely to push back planting dates for some growers and will just as likely put some cotton farmers in the undesirable position of deciding whether or not to replant a crop because of large skips in their stand.

“For replanting, if the producer is not able to replant due to continued lack of moisture and it is determined impractical to plant and approved by the insurance adjuster, the acreage is eligible for the full guarantee, say University of Georgia Ag Economist Don Shirley.

For example, a farm has an average yield of 790 pounds per acre and coverage is 70 percent. The yield guarantee would be 553 pounds per acre (790 x 70 percent). If the crop is appraised as a 30 percent stand, the production to count would be 237 pounds (790 x 30 percent) and the loss would be 316 pounds (553 – 237), Shirley says.

If the producer then decides to plant a second crop (other than cotton), the initial payment is 35 percent of this full amount. If the second crop is not insured or has no loss, the remaining 65 percent of the loss on the first crop (cotton) will be received, he adds.

Skips in a cotton field make any cotton farmer nervous, but some extra space between plants may not be such a bad thing when it comes time to decide whether or not to replant, says Clemson University Cotton Specialist Mike Jones.

“As a plant physiologist, I’ve always been interested in plant performance and have been amazed at how cotton plants can compensate for what seems like overwhelming damage to produce a good yield.

“I started working on seeding rate and plant populations a while back and continue to work on it from several different angles,” he says.

The first challenge a cotton grower has each year is getting an ideal stand. In most cases in the Southeast last spring growers weren’t able to get a good stand, Jones says.  When it comes time to replant just looking at big skips in rows of cotton may not be enough to justify the extra cost of putting more seed in the ground.

“In South Carolina last year we had problems with crusty soils that prevented seed from coming up properly. In our area we do a lot of strip-tillage, and poor seedbeds can be a problem. Poor seed quality is sometimes an issue, as is planting depth in our state,” Jones says.

Over the past decade the Clemson University researcher has done a series of tests in cooperation with national crop insurance to simulate impact of severe weather phenomena that occurs periodically across the Cotton Belt.

Seed has become expensive

The high value of cotton has driven up the cost of seed and the accompanying technology. Last year the cost of a bag of 250,000 seed-count cotton cost more than $300 a bag. So the natural thing to do is to try and stretch that $300 plus bag of seed over as many acres as possible.

“With our growers, we try to plant for 2-4 plants per foot of row, hoping to average three plants per foot. If the grower can average three plants per foot of row, typically you see one vegetative branch on the bottom of the plant, and it will have a few bolls on it.

“Most of the bolls are produced on fruiting branches, which develop every three days up the main stem and every six days out each fruiting branch. Over the course of a year there are lots of places on the plants to put on bolls and compensate for any kind of stress the plant faces early in the growing season,” Jones says.

Under a normal situation, all the bolls and lint produced on cotton are produced on fruiting branches. The ‘money bolls’ are produced closest to the main stem in the first position fruiting branch. When low plant populations occur, cotton plants under good growing conditions will shift those money bolls higher on the main stem and further out on the fruiting branches.

In low plant populations, growers are likely to see a large increase in number of vegetative branches and a high percentage of bolls under these conditions will come from these vegetative branches.

Like the main stem, vegetative branches take a long time to develop, so there will be late maturity when this occurs, Jones says.

Exactly how widely spaced cotton plants can be and still produce a high yielding crop depends on many environmental factors and on variety.

In his testing program over more than a decade at Clemson University’s Pee Dee Agricultural Research and Extension Center, Jones says cotton plants continue to amaze with their ability to compensate for a skippy stand.

In one series of tests, he grew two Deltapine varieties (50 and 90) back in the 1990s and hand thinned plants to produce side by side comparisons of cotton at 0.6 plants per foot of row in a 38-inch row, compared to 3.7 plants per foot of row.

What he found was no statistical difference in yield between the two plant populations.

Under higher plant population there was peak bloom earlier in the year — approximately three weeks earlier. There also will be significantly delayed boll set — usually about two weeks.

The delays in plant development carried over to about a 2-3 week delay in harvest, which could be significant in some years, Jones notes.

Delay in plant maturity

There was a definite delay in plant maturity with the lower plant population, but no significant difference in yield in any of the years in which these tests were conducted, he says.

In the lower plant situations, the bolls were larger and micronaire was higher. In some areas with a tendency to having high micronaire cotton this can be significant.

Calendar date is important. Cotton that would be replanted in early May might not need to be replanted by late May.

Variety selection and calendar date are directly linked. It is not a good idea to plant a full-season variety if the replanting date is past May 15. An early-maturing variety will do better when the season is shortened because of a late planting date.

Knowing the health of surviving cotton plants, both above and below ground, is critical to making sound decisions about replanting.

How healthy the remaining plants are will have a direct bearing on the profit potential of the field of cotton.

If replanting is necessary, continue to use insecticides and fungicides, especially if the first stand died from seedling disease.

Use a burn-down herbicide to kill the old stand of cotton and any weeds that may have emerged on the row.

There are plenty of theories on when to replant cotton because of low plant populations. The best probably comes from University of Arkansas Cotton Specialist Tom Barber, who says, “If you have enough cotton left to make the decision difficult, you probably have enough to keep.”

Based on research in the Southeast over the past 10-20 years, another criteria to use is: If you have 10 to 13 skips that are 3 feet or longer in 80 feet of row, then a replant will be justified.

In some cases a grower may “spot-in” areas of the field with his planter, however in many situations spot planting is not recommended because late-season management will be more difficult.

Though Jones’ research in South Carolina suggests even lower plant populations may produce comparable yields than the ideal 3-4 plants per foot of row, another popular theory on replanting is: 20,000 plants per acre range, or as low as 1.5 plants per row-foot with no or few skips.

If the stands are broken with numerous skips, replanting is in order at populations below 30,000 plants per acre, depending on the size and frequency of skips.

At the end of the day, each grower has to make his or her own decision on whether to replant a field of cotton. Knowing exactly what has happened to a field of cotton from the time it’s planted until a grower decides whether to replant is the ultimate criteria for making such an expensive decision.

[email protected]


Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.