Occurrence of diseases and pests in winter barley variety mixtures compared to pure stands

摘要

In an experiment conducted at two locations in Poland (Plant Breeding Station in Bakow and Research Station for Variety Testing in Slupia Wielka) during 2003/04 and 2004/05, diseases infecting 4 winter barley cultivars (Bombay, Gil, Gregor and Bazant) and their mixtures (Bombay/Gil, Bombay/Gregor and Gil/Gregor/Bazant) were studied. Among the winter barley diseases, only the incidence of powdery mildew (Blumeria graminis f.sp. hordei) was high. In 2003/04, the incidence of powdery mildew in mixtures was lower by 14-35% compared to pure stands (except mixture Bombay/Gil at Bakow). In 2004-05, the corresponding reduction was 25-31%. Pest occurrence in cultivar mixtures was also studied in 2004/05. The incidence of species under Agromyzidae was significantly reduced in all mixtures at Bakow (by 10-17%), but was not reduced at Supia Wielka. The populations of Oulema spp. were also lower for the cultivar mixtures at Bakow (Bombay/Gregor, by 27.5%) and Slupia Wielka (Bombay/Gil, by 26.9%, and Gil/Gregor/Bazant, by 7.1%)..