University of Georgia Cooperative Extension soils and fertility specialist Glen Harris cautions cotton growers and peanut producers about the impact that the current dry weather can have on essential nutrients in their respective crops.
“We have dried out a little. We’re hoping to get some good rains here in late July and going into August,” Harris said. “The two biggest concerns for me and the two biggest crops I work with is cotton and peanuts. With peanuts, it’s calcium. (The peanut plant) needs water to get that calcium into the nut. We put gypsum out, but we still need the water to get that calcium into the nut as it’s forming.
“Peak pod fill is 60 to 90 days. A lot of our peanuts are right there, right now. Irrigated (peanuts) will be fine. Gypsum on dryland is probably more important than irrigated because you’re more limited in moisture.”
Harris reported back in May that there was a potential for a gypsum shortage. Harris said the shortage stemmed from the fact that a lot of the coal burning powerplants that produce a lot of the “smokestack” gypsum that is used on peanuts shut down production of gypsum.
“There was a shortage and we had some people that had a hard time getting it. But overall, there was pretty much a pocket right up through the center of the peanut belt and that was mainly due to the plant that we were getting the gypsum from out of Macon switched to another source and wasn’t making that gypsum,” Harris said. “Luckily, the southwest corner had some stockpiled. In east Georgia, they use a lot of another product that comes into Brunswick on a boat from Spain. It was right in the center of the state where we had some issues. Overall, people might not have gotten it on the day they wanted it, but I think everybody ended up being able to do something. I think we got through that pretty well.”
Harris said he is already starting to receive questions on potassium concerns in cotton.
“It seems like when we get dry like this and have some issues with potassium being taken up, it could be there in the soil, but just not enough water to get into it. The question comes, can I foliar feed it? You can foliar feed potassium on cotton, especially if you get out there, third or fourth or fifth week in bloom; we don’t like to put it on the ground anyway,” Harris said. “But our rule of thumb is, if the cotton is wilted by noon, you probably shouldn’t foliar feed it. It’s under too much stress. As long as it’s not wilted by noon, a little bit of foliar potassium can get you by until, hopefully, it starts raining again.”
He added that one of potassium’s most important roles in the plant is with water relations.
“It opens up the stomates to let the water out or close them when it becomes dry,” Harris said.
Harris said that since the corn crop is in black layer, it should be alright.