The most common foliar diseases of wheat were at low levels in most parts of Kansas as of mid-April, but it is important for producers to be scouting their fields, said Kansas State University scientist Erick De Wolf.
"The crop is transitioning from the jointing to the flag leaf- emergence growth stages in many parts of the state with the most advanced growth stages occurring along the Oklahoma border," said De Wolf, a plant pathologist with K-State Research and Extension. He has been scouting wheat fields around the state and found the following:
Leaf Rust: Some leaf rust was discovered near Manhattan in March this year, but a recent visit suggested that it did not successfully make the move from older overwintering leaves to the new growth. These infections appear to have perished along with these oldest leaves. No leaf rust was found in fields visited the week of April 6-10 in Sumner, Reno, Harvey, and Republic counties. Texas and Oklahoma are reporting low levels of leaf rust in dryland fields, but more severe infections have been observed in irrigated fields in Texas.
Stripe Rust: Stripe rust has been reported in parts of central and northern Texas. The most recent reports suggest that stripe rust is currently at low levels but that recent weather favored the increase of disease.
Leaf spots and Powdery Mildew: The incidence of tan spot, speckled leaf blotch and powdery mildew is also low, and can only be found at trace levels in many fields in Kansas. Some fields do have active powdery mildew that should be monitored for signs of increasing severity.
"In general," De Wolf said, "the overall risk of foliar disease appears to be lower than in 2007 or 2008. However, recent rainfalls may stimulate additional disease activity. As the crop moves through the flag leaf emergence and heading stages of growth, growers should be scouting for signs of disease weekly."