Ecological production of dryland hairy vetch by mechanical control

Abstract - Winter hairy vetch, Vicia villosa Roth, gives high grain and hay yields. Mechanical control of weeds is an ecological alternative to the use of herbicides. Among the various mechanical methods, interrow weeding is cheap and practical. Nonetheless, wider row spacing than common practice is needed to ease the operation. We optimized row spacing and seed rates for high grain yield and to ease interrow cultivation. We used two row spacings of 45 and 60 cm as main plots and five seeding rates of 100, 200, 300, 400 and 500 seed per square meter as subplots. Experiments were conducted in rotation with winter wheat in 2001, 2002 and 2003. The results showed that narrow spacing and high seed rates increased the grain yields of winter hairy vetch. In contrast, wide row spacing reduced the grain yield by 56%. More plants per square meter were obtained with 60-cm row spacing and high seed rates. Row spacing of 60 cm increased the branch number per plant in the dry year and decreased it in the wet year.