SAMPLING WHEAT (TRITICUM-AESTIVUM) AT THE ELEVATOR FOR JOINTED GOATGRASS (AEGILOPS-CYLINDRICA)

Winter wheat grain contaminated with jointed goatgrass joints is often discounted as much as 20% by grain buyers. A mail survey to Nebraska farmers in 1984 identified jointed goatgrass as One Of the ten worst w eed problems in winter wheat, but a field survey to the same area in 1 986 found it in less than 1% of surveyed fields. The objective of this survey was to map the geographic distribution and severity of jointed goatgrass contaminating winter wheat grain in western Nebraska. Joint ed goatgrass was found in 25, 29, and 20% of all wheat samples collect ed in 1990, 1998, and 1992, respectively. Nebraska counties bordering Colorado were found to have the highest percentage of wheat samples co ntaminated with jointed goatgrass joints, ranging from 23% in Cheyenne county in 1992 to 61% in Keith county in 1991.