Interference between Echinochloa crus-galli and soybean.
Field trials were conducted at Kostinbrod, Bulgaria, in 1988-90 to investigate the competition between E. crus-galli and soyabeans. Soyabean yield in all treatments with weeds was decreased compared with controls, the decrease depending on the degree and duration of weed infestation and meteorological conditions, particularly air temp. In years when meteorological conditions were favourable for crop growth, the competitive ability of the crop increased and E. crus-galli had a lower biomass. Soyabeans were most sensitive to E. crus-galli during the emergence-anthesis period.