Cooler Weather Hindering Crop Development

Sandy Stewart, Saichuk, John K., Blanchard, Tobie M.  |  5/10/2005 2:23:40 AM

News Release Distributed 05/09/05

While April’s weather might have seemed near perfect for some, the cooler-than-normal weather wasn’t welcomed by everyone.

The mild, dry weather was ideal for most people – but not ideal for some crops, according to the experts who explained most of us appreciate a reprieve from hot, humid weather, but tropical plants like cotton and sugarcane prefer to see the mercury rise.

Crops that should be experiencing growth right now, such as cotton, sugarcane and rice, are slowed by the cool weather, LSU AgCenter experts say.

"Some nighttime temperatures in the low 50s or high 40s are not good for an emerging cotton seedling – particularly if it comes along with a north wind," said LSU AgCenter cotton specialist Dr. Sandy Stewart.

The cotton seedling, in its early stages, is vulnerable to the insect thrips and seedling diseases. Stewart said warmer weather helps the seed emerge and grow quicker, making it less vulnerable to these problems, but while the weather stays cool, the cotton does not grow as quickly.

The pleasant weather pattern so far this spring also is hindering the development of sugarcane. Stands are short, and leaves are tinted purple – an indication of cold stress, according to another LSU AgCenter expert.

"Our growth measurements have indicated that cane is growing less than a half an inch a week," explained Dr. Ben Legendre, the LSU AgCenter’s sugarcane specialist. "At this time of the year, you would typically have anywhere from 2 to 3 inches a week."

Sugarcane grows best when nighttime temperature stay above 60 degrees, and the crop prefers nighttime temperatures in the 70s.

Worse yet, the cooler-than-normal weather isn’t the only problem affecting sugarcane. Dry conditions during planting season late last summer and early fall also are hindering the development of the sugarcane.

"The seed cane just dehydrated, and we didn’t really know how bad it was going to be until the spring, and with the cool, wet December and January, that further stressed the cane," said Legendre.

Legendre estimates that 2,500 acres of cane that was planted last year may have to be plowed up and that another 5,000 to 10,000 acres is weak. These factors leave little chance for a bumper crop this year.

"What we need now is to have these warm temperatures come in as soon as possible, and we’d like to get timely rainfall during the season and hopefully come September we can have a normal crop," Legendre said.

A return to normal conditions also would benefit rice growers.

"Rice growth is triggered by temperatures," said LSU AgCenter rice specialist Dr. Johnny Saichuk. "When temperatures are below 50, like we saw some nights in April, there is no growth."

Saichuk tracks rice’s growth and development by measuring the amount of heat – using a measure of heat units per day. He said the total is behind by 275 heat units, a significant amount, which, like for other crops, translates into slow growth.

"The crop is about 10 days to two weeks behind schedule," Saichuk said.

A delay in the crop could greatly affect the second crop of rice that farmers often make in the fall.

"We need to harvest the first crop by Aug. 15 or we won’t get much of a second crop," the LSU AgCenter expert said.

On the other hand, Saichuk did express that this weather pattern is better than all the rain Louisiana experienced this time last year.

"The good side of it is we’ve got lots of sunshine," he said.

The lack of rain, however, does mean that farmers have to pump more water on their field at a time when fuel costs are at a record high.

"Delaying the crop is not a disaster," Saichuk explained. "Biologically the crop should be good, but it could be bad economically for growers."


Sandy Stewart at (318) 473-6522 or
Ben Legendre at (225) 642-0224
Johnny Saichuk at (337) 788-7547 or
Tobie Blancard at (225) 578-5649 or

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