Storability of wheat infected with Fusarium head blight

The effect of scab (Fusarium head blight) on storability of three varieties of hard red spring wheat (Triticum aestivum) grown in several locations an d in two years was studied. Samples of scab-infected hard red spring wheat were collected from west-central and northwest Minnesota after harvest in 1 994 and 1995. Half of each sample was passed over a gravity table twice to remove as many of the scab-infected kernels as possible. Carbon dioxide evo lution from cleaned and uncleaned samples was then used to determine dry ma tter loss during storage at 16, 18, and 20% moisture (wet basis) and 20 deg rees C. Several quality factors and U.S. grade number were determined befor e and after storage, and the time required to reach 0.5% dry matter loss wa s determined. The storage time to reach 0.5% dry matter changed from -1.6% to +43.3% for samples that had been cleaned to remove scab-infected kernels compared to samples that had nor been cleaned. There was no consistent tre nd in levels of the mycotoxin deoxynivalenol (DON) during storage of 1994 w heat, but in most cases, there were significant increases in the levels of DON during storage of 1995 wheat. In all cases, DON levels were lower after storage tests in samples that had been cleaned on the gravity table compar ed to samples that had not been cleaned. Wheat stored at 16% moisture deter iorated at a much slower rate than would be expected for corn (Zea mays) st ored under similar conditions, and a wheat variety that is somewhat resista nt to the fungi that cause scab deteriorated more slowly than varieties tha t are susceptible to scab fungi. There were large, unexplained differences in storability for wheat grown in the two years of the study. In both years , however, the 0.5% dry matter loss criterion that is used to determine all owable storage time for corn seemed to be too high for use with wheat.