EFFECTS OF WINTER CROPS ON YIELD AND PLANT HEIGHT OF SOYBEANS

In a trial conducted from 1980 to 1988, at the National Wheat Research Center in Passo Fundo, RS, Brazil, the effects of winter crops grown for grain - barley (Hordeum vulgare L.), rape (Brassica campestris L.), flax (Linum usitatissimum L.) and wheat (Triticum aestivum L.) as well as for mulching - white oats (Avena sativa L.) - on yield and plant height of soybeans were assessed. The leguminous crop was direct seeded into the soil in a randomized block design with four replications. In most of the years and for the overall mean there were effects of winter crops on soybean yield and plant height. When soybeans were grown after rape or after wheat monoculture its height was lower and yielded less than after the other crops.