Tuesday, December 16, 1997

Shedding more light on cotton can boost yields

By J.T. SMITH / Farm Editor

Some cotton growers may try planting cotton earlier to boost yields.

While we often take ample sunshine for granted - some parts of the Cotton Belt are coming up short.

Planting Mid-South cotton a month earlier could shift the peak flowering period to yield more cotton bolls and fiber.

That's the finding of the USDA Agricultural Research Service.

ARS scientists at the Cotton Physiology and Genetics Research Unit in Stoneville, Miss., investigated earlier planting times because cotton in the Mid-South region suffers from insufficient sunlight.

The Mid-South region includes Mississippi, Arkansas, Louisiana and western Tennessee.

Aiming for the summer solstice

In the study, the ARS scientists planted cotton during the first week of April - or a month earlier than usual for the Mid-South.

This "ultra-early planting" shifts the peak flowering period closer to the summer solstice - the longest daylight period - when plants can soak up more light.

The early cotton produced about 11 percent more fiber yield than cotton planted at the traditional time.

Cotton planted in April also flowered about two weeks earlier than the other crop.

This also would let growers harvest and the get the crop to the market earlier.

Prices are generally higher earlier in the season when available supplies of cotton are lower.

Yet another advantage of early maturity was the avoidance of greater insect pressures that occur later in the season.

Disadvantages can include cold stress

One disadvantage to ultra-early planting is that some plants may suffer early-season cold stress.

Certainly in this Abilene region, it would could be difficult since April has proven to be a cold month for a number of years now.

In 1997, we had record April cold at mid-month.

And most folks will recall the record (for any date) Good Friday snowfall that came on April 5, 1996.

But for the Mid-South, the scientists found that even if plants were cold-stressed, yields can be about the same as for normal planting.

But scientists are trying to identify cold-tolerant varieties.

Of course, before an earlier planting date could be seriously considered in our region, the boll weevil would need to be be eradicated.

Any early cotton fruit here on the Rolling Plains of Texas would help weevils coming out of winter hibernation to survive.

Without early food, millions of weevils starve.

Perhaps when the weevil is eradicated, farmers will some day be free to attempt early cotton without worrying about the pest consequences.

Zapping grain pests with light

Speaking of light, the scanning of individual wheat kernels with the energy of near-infrared (NIR) light waves can reveal hidden insects that lower the quality of wheat.

NIR can also identify and kill the pests.

On Monday, the USDA reported its findings at a meeting in Nashville, Tenn.

In studies during wheat harvest season last June, exposing wheat kernels to NIR killed 100 percent of the rice weevil larvae infesting them.

The USDA scientists are the first to combine NIR with an automated grain handling system to rapidly detect hidden insects in wheat kernels.

Damage from the lesser grainer borer, rice weevil and maize weevil costs the U.S. wheat industry $500 million annually.

A rice weevil may look just like a granary weevil.

But based on the insect's "light signature" in its body content of carbon, hydrogen and nitrogen - the scientists can tell which is which.

And they can zap the rascals.