VELVETLEAF (ABUTILON-THEOPHRASTI) RECRUITMENT, SURVIVAL, SEED PRODUCTION, AND INTERFERENCE IN SOYBEAN (GLYCINE-MAX)

Field studies were conducted at Rosemount, MN, in 1992 and 1993 to qua ntify the demographic processes regulating the population dynamics of velvetleaf in soybean as part of a corn-soybean rotation. A consistent 6.8 +/- 0.5% of the total velvetleaf seedbank emerged each year, Less than 21% of all velvetleaf seedlings survived each year in mixture wi th soybean, due in part to Verticillium spp wilt infection, The probab ility of seedling survival varied across time of emergence, Velvetleaf seed production in the absence of crop competition was 125 and 227 se eds plant(-1) in 1992 and 1993, respectively, Velvetleaf plants that e merged early produced greater numbers of seed than later emerging plan ts, Velvetleaf survival and seed production were reduced up to 82% in the presence of crop competition, Soybean yield varied across soybean densities in both years, but was not reduced across velvetleaf densiti es.