Last week (week of 4/1) stripe rust and leaf rust were observed in parts of Kansas, meaning Nebraska wheat growers should be scouting now for rust diseases, a University of Nebraska-Lincoln Extension plant pathologist says.
“The detection of leaf and stripe rusts in Kansas indicates that we are likely to see these diseases in Nebraska in the next two to three weeks,” said Stephen Wegulo, UNL Extension plant pathologist in the university’s Institute of Agriculture and Natural Resources.
Nebraska wheat is about two weeks ahead of normal crop development this year due to the unseasonably warm temperatures this winter and spring, he said.
With above normal temperatures in the forecast and if rainfall occurs, that combination could also lead to rapid development of foliar diseases in wheat including powdery mildew and fungal leaf spots.
“These have already been observed in southeast Nebraska,” Wegulo said. There also have been reports of general yellowing of wheat fields.
This condition is common at the current growth stage and can be caused by several factors, including inadequate fertilization and virus diseases. If the yellowing is of a general nature with no obvious virus symptoms (stunting and leaf mosaics, mottling or streaking), it is most likely due to inadequate fertilization.
“The wheat crop usually grows out of this condition and greens up as the growing season progresses,” he said.
Wheat growers should scout fields routinely so timely management decisions can be made.
For more information about scouting wheat fields, including treatment information, visit CropWatch, UNL Extension’s crop production newsletter here.