Allelopathic potential of winter and summer cover crops on the germination and seedling growth of Solanum americanum

Sustainable weed management strategies are important for reducing chemical inputs and development of weed resistance. This study aimed to evaluate the effect of extracts from winter cover crops (cereal rye, black oat, forage turnip, and common vetch) and summer cover crops (jack bean, velvet bean, and brown hemp) on seed germination and seedling growth of glossy nightshade (Solanum americanum Mill), under controlled conditions. The aqueous extracts were produced from the shoot biomass of cover crops at concentrations of 0%, 25%, 50%, 75%, and 100%. Fifty S. americanum seeds were placed on Germitest paper moistened with 15 mL of each extract concentration. Cereal rye extract at the highest concentration reduced total germination to 43% and caused a 62% reduction in the germination rate index (GRI) of S. americanum. Velvet bean extract reduced germination, GRI, and seedling growth of S. americanum from the lowest concentration applied, while concentrations of 75% and 100% completely suppressed seedling development. Decomposing cereal rye and velvet bean cover crops have potential to suppress germination and growth of S. americanum. Efficient cover crops could reduce herbicide applications, and thus improve herbicide resistance management.

Automated summary

This study evaluated the effects of different cover crop extracts on seed germination and seedling growth of glossy nightshade, finding that extracts from cereal rye and velvet bean had inhibitory effects. Efficient cover crops could potentially reduce herbicide applications and improve herbicide resistance management.