The Mid-South wheat crop has the potential to produce great yields. If such yields materialize, though, it will be in spite of disease, area agronomists say (see story beginning on Page 1).
“No doubt about it, we're seeing an increase in diseases in our wheat,” says Erick Larson, Mississippi Extension wheat specialist. “We saw a lot of glyphosate drift in our crop a few weeks ago and are still waiting to see what kind of impact it could have on our yield potential. Now, we've got diseases sneaking up.
“In general, though, I don't think we're seeing incidences of disease as prevalent as in Arkansas and Louisiana.”
Stripe rust is “hanging around” Louisiana much longer than was anticipated, says Ed Twidwell, the state's Extension wheat specialist. “It's probably the biggest problem we've got going currently. In some areas it's bad enough it will probably affect yields.”
Normally, Louisiana stripe rust would have been finished two or three weeks ago. But with low nighttime temperatures it's having little trouble.
“When nighttime temps are in the 50s, stripe rust thrives. Some producers have sprayed for stripe rust at least twice. Usually, one application of a fungicide is enough. With $4-plus wheat, producers are much more willing to spend money to save the crop.”
Stripe rust has shown up in pockets all over the state, says Twidwell, who is based at the Macon Ridge Research Station in Winnsboro, La. His centrally located demonstration plots have been hit hardest, however.
USDA has Louisiana's wheat acreage pegged at 150,000 — a number Twidwell suspects could be “a little low.”
It's too early to comment on what the last few days of rain have done to Arkansas' crop, says Jason Kelley. Some central Arkansas areas have gotten 5 or 6 inches of rain with more forecast.
“If it'll stop now (Friday), then I don't think it'll have an effect,” says the Arkansas specialist. “Right now, south of I-40 the crop is all flowering or past flowering. North of I-40, there are some areas that are just at flowering.”
USDA has the state projected at 720,000 acres of wheat. “The winter estimate had us at 680,000 acres,” says Kelley. “A lot of people thought that acreage estimate was a little low and are happy they readjusted it.”
Both leaf and stripe rust have shown up in the state.
“Some warm temperatures held the stripe rust in check,” he notes. “There have been fields treated, but not as many as we feared when the disease showed up
“Leaf rust didn't really take off until late. Right now, many of our fields are beyond the legal application window for a fungicide. Once we get to flowering, we can't do much. Now, unfortunately, we've just got to wait to see what happens.”
For the most part, Mississippi has had “really good” growing conditions for its estimated 220,000 acres of wheat, says Larson. Most of the crop is just finishing flowering stages.
Larson says there is a concern about lack of moisture in areas that didn't receive a good rain over Easter weekend. “If we continue having dry weather, we could run out of moisture before the wheat crop matures. Areas in the south Delta are drier than in the north Delta and need a rain in the next couple of weeks.”
Mississippi producers seen quite a bit of barley yellow dwarf. Most of it appears to be from spring infection.
“Clumps of plants about the size of a basketball are infected. We're not seeing a lot of stunting yet. So far, I think yield effects will be minor. But infection is very frequent throughout the crop.”