Foliar diseases can take a bite out of Louisiana’s wheat yields some years. Trouble is growers can’t always know which year that will be until symptoms begin to appear.
Paul “Trey” Price, field crops plant pathologist at the Tom H. Scott Resaerch & Extension Center, near Winnsboro, La., talked to growers about how to identify those diseases and prepare for them during a stop at the annual Wheat and Oats Field Day at the station.
Price showed attendees samples of six foliar diseases: Fusarium head blight or scab, stripe rust, leaf rust, loose smut, barley yellow dwarf and septoria leaf blight. Most of the samples that had been pulled from another location on the station.
He listed symptoms of the diseases and possible treatments based on LSU AgCenter recommendations. Those can include seed treatments, foliar fungicide applications or planting resistant varieties. AgCenter specialist have included several resistant lines in their variety recommendations which are published each year.
“Stripe rust actually prefers this weather, 50 to 59 degrees F,” said Price. “Last year we had incredible stripe rust pressure here on the station. We had some plots that were reduced 50 percent. The good news is that if you plant a resistant variety you don’t have to worry about stripe rust. So you can save that money on the fungicide application.
“The other good news is that fungicides are effective on stripe rust so if you plant a susceptible variety to stripe rust we have fungicides that are very good at controlling the disease using an application around F8 or flag leaf.”
Some of the other diseases, such as leaf rust, are also susceptible to fungicides while others are best controlled through planting resistant varieties. Price distributed a new Wheat Disease Identification Guide, a publication authored by Erick DeWolf and James P. Shroyer of Kansas State University and other plant pathologists in wheat-growing state. Copies of the guide can be obtained from USDA and state Extension Services.