Control of plant diseases through crop rotation: a Latin American experience

摘要

Due to high rainfall (900 mm during wheat growing season) many diseases attack wheat in Southern Brazil. Integrated disease control strategies to control them include breeding for rusts, powdery mildew, and viruses; seed treatment with fungicides forcommon root rot and leaf blights; and fungicides sprayed on above ground plant parts to control rusts and leaf blights only when epidemics reach the economical damage threshold. Control has efficiently controlled takeall, common root rot, and leaf blights. It has been shown that pathogens that saprophytically survive in crop retidues and do not have resting structures are reudced by one winter rotation with alternative monhost crops. In Southern Brazil wheat residues break down in a period of 12-17 months. Main alternative crops that are being used include oats, vetch, and rape.