CROP-ROTATION IN GUARAPUAVA .14. EFFECTS OF WINTER CROPS SUCCESSION SYSTEMS ON SOME AGRONOMIC CHARACTERISTICS OF CORN UNDER NO-TILLAGE

During six years the effects of common vetch (Vicia saliva L.), and lu pins (Lupinus sp.) on corn (Zea mays) were evaluated at the Cooperativ a Agraria Mista Entre Rios Ltda., Guarapuava, PR, Brazil. Corn was est ablished under no-tillage system in a complete randomized block design with four replications. Corn was hand-harvested in plots of 60 m(2). In corn cultivated after a) common vetch and wheat or b) after common vetch, wheat and flax grain, yield and number of kernels per plant wer e higher than under c) after lupins, wheat, oats, and barley. Incremen ts in number of kernels per plant resulted in higher corn yield observ ed under rotation system. Common vetch showed to be the species with t he greatest potential for use as an alternative crop for wheat or corn in rotation systems.