AGRONOMIC CHARACTERISTICS AND CONTROL OF BARLEY ROOT DISEASE, UNDER NO-TILLAGE, IN ROTATION WITH OTHER CROPS

From 1984 to 1993, at the Cooperativa Agaria Mista Entre Rios Ltda., G uarapuava, PR, Brazil, the effects of some crop rotation systems on yi eld, root disease control, and yield components of barley were assesse d. Four rotation systems were studied: 1) monoculture; 2) one winter w ithout barley; 3) two winters without barley; and 4) three winters wit hout barley. The crops grown in Summer were soybean and corn. Both Win ter and Summer crops were grown under no-tillage, except in the Winter of 1989, when limestone was applied before planting winter crops. A r andomized complete block design, with four replications and plots with 60 m(2), was used. The crop rotation was efficient in controlling roo t diseases of barley. The crop rotation of barley under no-tillage con trolled root diseases.