As the calendar speeds toward harvest, Arkansas’ cotton growers are hoping the mercury will remain above 60 degrees at night for just a little longer.

“We need some warmer weather,” said Tom Barber, Extension cotton agronomist for the University of Arkansas Division of Agriculture. “If we can see highs in the 80s and keep the average above 65 degrees overnight, we’ll probably get everything to work out like we want them to.”

Cotton is a tropical crop that revels in high daily temperatures, but also needs cool evenings for optimal development.

“It just seems to be a little cooler this month. I’m wearing long sleeves.”

So far this month, using readings at Pine Bluff, there have been six days that peaked at 90 degrees or higher with an average daily max temperature of 85.6 degrees through Sept. 18. However, the average low is well below that optimal 65-degree reading at 59.9 degrees, according to the National Weather Service. In 2010, the average September daily maximum temperature was 91.4, with the average daily low being 63.9. Two years ago the average daily high was 91.4 and the low was 63.9.

Cotton growers have been prepping fields for harvest since the second week of September, applying defoliants that will allow the harvesters to grab the bolls. Low temperatures below 65 degrees reduce the effectiveness of the defoliants.

“In general, we’ll have an average crop. Some of it will be a little light due to late planting.”

Still, Barber said he expects “we’ll be pleasantly surprised” with what comes out of the state’s cotton fields.

Last week, in its crop production report, the National Agricultural Statistics Service was forecasting cotton production to be up from 2010.  NASS was forecasting harvested cotton acreage at 660,000 acres, up 20,000 acres from its Aug. 1 forecast.

All cotton production is forecast at 1.4 million bales, up 100,000 bales from the Aug. 1 forecast and up 224,000 bales from last year. Yield is expected to average 1,018 pounds per harvested acre, up 43 pounds from the Aug. 1 forecast but down 27 pounds from last year’s yield.

For more information about crop production, contact your county Extension office or visit www.uaex.edu or www.arkansascrops.com.