VELVETLEAF (ABUTILON-THEOPHRASTI) INTERFERENCE IN SOYBEAN (GLYCINE-MAX) - A SURVEY OF YIELD LOSS ESTIMATES AND MANAGEMENT RECOMMENDATIONS

Velvetleaf plants were placed between 76 cm soybean rows at a density of one velvetleaf every 6.1 m of row in early September. Later that mo nth, farmers and agricultural-industry employees who were attending a university field day were asked to predict the yield loss caused by th is infestation. The average yield loss estimate by 90 farmers was 5.7% , whereas 45 agricultural-business employees predicted a 5.3% yield lo ss. NebraskaHERB, an economic threshord/post-emergence decision making tool developed at the University of Nebraska, predicted a 4.3% yield loss from this weed infestation. Recommendations for managing the velv etleaf were influenced by the person's yield loss estimate. Recommenda tions made by industry personnel were closer to the computer based dec ision judgement than those of farmers. (C) 1997 Elsevier Science Ltd.