The months-long streak of mostly dry, 95-plus degree days has been a double-edged sword for Arkansas cotton and soybean producers.
“Sixty-eight to 86-degree weather is ideal for soybeans and cotton,” said Mike Hamilton, Crittenden County extension agent for the University of Arkansas Division of Agriculture. “Nothing is thriving in this excessive heat.”
Speaking from a soybean field, Robert Goodson, Phillips County Extension agent for the University of Arkansas Division of Agriculture, said the weather’s effect on soybeans depends on what maturity group is in the field and whether it is irrigated. There is heat stress. With irrigation, it’s not hurting us. Right now, we’re in dryland beans and they’re suffering.”
The long streak of dry days has made a mark in Phillips County, Ark., with the yield in early-maturing dryland beans not quite up to the county average for all bean types. A prolonged dry period will spell trouble for later maturing varieties — soybeans that would normally be harvested in late October.
“They’re suffering more than the others — they’re just trying to grow now,” said Goodson. “If you could make it rain 2.5 inches every Friday that would be nice.”
Hamilton said in his county the soybean pods are plumping up, but “they seem to have slowed down.”
Growers are running water pumps, but “irrigation hasn’t gone as far as it normally goes. Soybeans use about three-tenths of an inch of water per day, so the spotty rainfall isn’t going to do much.
“A 1-inch rain will only last you three days. There’s been a lot of quick evaporation … pumps have been running all day, every day.”
The triple-digit heat began in June. The National Weather Service reported triple digits at Jonesboro, Ark., on June 21, and El Dorado, Fort Smith and Pine Bluff on June 22. There were four bouts of severe storms July 6-9, 11-13, 15-17 and 25-27, but much of the rainfall was spotty and evaporated quickly.
For cotton producers, the early heat proved beneficial.
“If there’s good news, we have a really early crop,” said Don Plunkett, Jefferson County Extension staff chair for the University of Arkansas Division of Agriculture. “The heat was not excessive early in the season and that sped the crops up.”
The downside is that “anytime it’s over 95 degrees during the day and higher than 75 degrees at night, the small bolls will shed. The heat is not good for boll production.”
Hamilton was seeing the same in Crittenden County cotton. “The extreme hot and dry weather has caused a considerable amount of fruit shed. We’re shucking fruit when we shouldn’t be.”
Hamilton has heard many complaints about how the heat is making it harder to manage pests. “We’ve had a large number of bollworms accompany the extreme heat. The pesticide has trouble getting down in the canopy and is less effective.”
On Tuesday, Plunkett said some fields are infested with a combination of yellow stripes, bollworms, fall armyworms, some salt marsh caterpillars and “the farmers are concerned about the defoliation they’re seeing.”
Some rice growers are reluctant to turn off the wells, a normal practice in anticipation of harvest, even with the grain heads filled out 75 percent. Plunkett said that during lunch Tuesday, he heard some producers say “‘If I turn my wells off now on some of these silt-loam fields, in two days, they’ll have to be turned back on. The crop is sucking up the water and the heat is increasing evaporation.’”
In an ideal year, water would be diverted from rice to later maturing soybeans. However, the overall picture in Jefferson County isn’t too bad.