DISTRIBUTION AND OCCURRENCE OF MYCOTOXINS IN 1993 KANSAS WHEAT

Wheat samples from various locations in Kansas were tested for mold in vasion by plating on agar medium and then analyzing for the presence o f deoxynivalenol, zearalenone, and aflatoxin B-1 using thin-layer chro matography. In eastern Kansas, 29 of 30 samples (96%) were invaded wit h Fusarium graminearum and the mean percentage of invaded kernels was 33% in northeast, 16% in east central, and 15% in southeast districts. The highest level of invasion observed was 75% on a sample from north east Kansas. Deoxynivalenol was detected in 23 of 116 samples analyzed (20%) and was correlated highly (r = 0.839, P < 0.001) with the level of invasion by F: graminearum. Zearalenone was detected only in one s ample from northeast Kansas. Cool, wet weather during 1993 was an impo rtant factor affecting invasion and toxin formation by F. graminearum. The level of mycotoxin in 1993 Kansas wheat was relatively low.