TEMPORAL AND SPATIAL DISTRIBUTIONS OF VELVETLEAF SEEDLINGS AFTER 1 YEARS SEEDING

Two separate experiments were conducted from 1974 through 1980 and fro m 1976 through 1982 at an experimental farm in southwestern Ontario, C anada, to determine the pattern of temporal and spatial distributions of velvetleaf seedlings from seed produced by uncontrolled plants. For each experiment, a soybean field with no previous record of velvetlea f infestation was selected and planted with four patches of 10 velvetl eaf plants. The plants were allowed to grow to reproductive maturity f or 1 yr, and the density and spatial distribution of velvetleaf seedli ngs within the field were mapped over the next 6 yr. Although velvetle af seedlings emerged each year after seeding, the highest percentage e merged the second year after seeding. Velvetleaf seedlings emerged at locations with or without a seeding plant, but a high density of emerg ed seedlings was often observed at locations some distance away from t he seeding plants. The results suggest that under conventional harvest ing methods there may not always be a close spatial relationship betwe en the distribution of parent plants and their offspring, depending on the scale of the land and biotic and abiotic environmental conditions .