Unless a powerful weather event intervenes, it looks like North Carolina wheat growers will produce a very big crop this year. At least, that is how things looked to Randy Weisz, Extension small grains specialist, early in March.
The crop looks very good, he says. “Most fields look great right now. But there is some concern in some areas because the warm weather has really pushed the crop forward in a hurry, especially early heading varieties. That could give us trouble if there is a freeze in the next few weeks. But barring that, it looks like we are heading for a very good harvest.”
But there was still time for some of this year's wheat to fall victim to either of two production problems, powdery mildew and Hessian fly.
Weisz was already advising farmers to scout for powdery mildew in March.
“You should probably be looking for powdery mildew, although it is unusual to see it this early,” he told Southeast Farm Press on March 6. “But we have seen it in places in North Carolina, so be on the alert.”
When powdery mildew strikes, it looks like snow on the leaves, Weisz says. It is well worth it to take control measures if you get the disease on your wheat.
“Probably the best chemical for powdery mildew is Tilt, but any of the strobilurins will be fine,” he says. “There is a spray threshold. When 5 percent to 10 percent of leaves have the fungus, that is the time to spray.”
Hessian fly is a relatively new problem for North Carolina wheat producers and frequently doesn't cause enough damage to be economic. But it was a major cause of yield loss for a few northeast North Carolina and southeast Virginia farmers in 2007.
Weisz had already seen enough Hessian flies in late February that he expected a spray alert would be needed later on. “At some point in the next few weeks, when it is warranted by Hessian fly populations, I will send out an alert,” he says. “That will mean that if you have an infestation, it is time to trigger an insecticide program.”
He thought they might first emerge in the southern end of the Coastal Plain, perhaps around March 15.
“When a field has Hessian fly, you see areas of very thin stands,” he says. “If you dig up the plants, you can see fly pupae at the bottom.
“Our county agents know what these things look like and they are aware of the situation. If you think you have Hessian fly, consult with your county agent.”
Don't just run out and spray until you have sought advice. “The spray has to be timed carefully. But one well-timed application should have a positive effect.”
For Hessian fly, you need a pyrethroid insecticide with long residual control, says Weisz. “At this time, Warrior is about the only choice.”
The sheer volume of wheat in North Carolina may cause some harvest time problems, says Weisz. “We have 200,000 more acres than last year, and getting it all stored is going to be a challenge.”
Weisz is afraid that scheduling problems may develop at harvest. “With this additional acreage, if we have a good crop in North Carolina, our grain handling infrastructure may be overwhelmed,” he says. “A farmer could arrive at his buyer and find the buyer unable to take it that day. What are you going to do? You need a plan for short-term grain storage if you get caught in that situation.”
Manganese deficiency could limit yield on some wheat fields this year, says Rick Morris, regional agronomist with the North Carolina Department of Agriculture and Consumer Services.
Morris says he received a large number of calls in the winter and spring related to manganese deficiency, especially from growers in southeastern North Carolina counties. “Most of them had the same problem — yellow areas in wheat fields. Soil tests and plant tissue analyses indicate that manganese deficiency is the cause.”
Manganese is a nutrient that plants need in small amounts, Morris says. “It is normally sufficient in soils in our area. Problems occur, however, when soil is limed so the pH rises above 6.2. When this happens, manganese is still present in the soil, but it becomes unavailable to the crop.”
An NCDA&CS regional agronomist or other local agricultural adviser can give advice on collecting soil and plant tissue samples to diagnose the problem. If a manganese problem is confirmed, timely foliar sprays may alleviate the situation before yield loss occurs.
The warm environmental conditions last fall and winter will make this problem more apparent, Morris says. “There is probably more vegetative growth above ground than there is root system to uptake nutrients. Growers need to take care of this problem now before yield potential is seriously jeopardized.”