Identification of allelopathy in the USDA-ARS rice germplasm collection

Abstract

Field experiments in 1988 and 1989 identified rice accessions from the USDA-ARS rice germplasm collection for allelopathic effects to ducksalad [Heteranthera limosa (Sw.) Willd.]. About 10000 accessions were evaluated; 347 accessions had apparent allelopathic activity. Accessions that had demonstrated allelopathic activity to ducksalad in 1988 or 1989 were evaluated further for allelopathic activity in 1990 (67 accessions) and 1991 (47 accessions). In 1990, 12 accessions had a radius of activity of 0.18-0.20 m and 80-90% weed control within the area of activity. In 1991, 12 different accessions had a radius of activity of 0.13-0.18 m and 50-85% weed control in the area of activity.