It´s that time of year when rainfall is nurturing the developing wheat crop—and the diseases that thrive on it.

Leaf rust, tan spot and powdery mildew have all been reported in some Kansas counties. That has prompted a Kansas State University plant pathologist to encourage producers to scout diligently and to remember pre-harvest intervals if they apply a fungicide.

"It´s important to remember to carefully evaluate the pre-harvest interval (PHI) for all fungicide products," said Erick De Wolf, wheat specialist with K-State Research and Extension. "The labeling of many fungicides will prohibit application after full head emergence. The fungicides Foilcur, Prosaro, Caramba and Proline can be applied slightly later, and allow applications up to the time wheat plants are at the 50 percent flowering stage. All four of these products have a 30-day PHI.

In its weekly report issued May 11, the Kansas Agricultural Statistics Service reported that wheat disease infestation was rated as 71 percent none, 23 percent light, and six percent moderate as of May 10.

KASS also reported that 95 percent of the wheat had jointed, compared with 89 percent last year, and 97 percent for the five-year average. Thirty-two percent had headed versus 17 percent last year and 49 percent for the five-year average. The wheat condition was rated three percent very poor, nine percent poor, 37 percent fair, 43 percent good, and eight percent excellent.