The weed control potential of oat cultivars

Winter-killed oats (Avena sativa) may have potential for use to suppress weeds in early seeded crops such as pea (Pisum sativum). Residue biomass and surface coverage are generally correlated with weed suppression. Oat residues also contain allelochemicals. Our objective was to determine if oat cultivars vary in residue production and allelopathy. Differences between oat cultivars were observed in residue production, and for effects on emergence of common lambsquarters (Chenopodium album) and shepherd's-purse (Capsella bursa-pastoris) in the greenhouse, and germination of pea and common lambsquarters in an infusion assay. Two of the oat cultivars producing the greatest biomass, 'Blaze' (in the field) and 'Classic' (in the greenhouse), interfered minimally with pea germination and were among the best cultivars in inhibiting common lambs-quarters and shepherd's-purse. 'Blaze' also greatly inhibited common lambs-quarters germination in the infusion assay that measured allelopathy. Thus, 'Blaze' and 'Classic' possess suitable characteristics for use as a cover crop preceding peas.