Greenhouse studies were conducted to evaluate the influence of wild radish–amended soil on tomato, bell pepper, and yellow nutsedge growth. In addition, yellow nutsedge interference with tomato and bell pepper was evaluated with and without the wild radish amendment. Leaf margins of tomato and bell pepper plants were necrotic for approximately 2 wk after transplanting into soil amended with 1% (wt/wt) wild radish biomass. Injury to both crops was transient, but bell pepper biomass through 9 wk after transplanting was negatively affected, whereas tomato was not. In a replacement series study, tomato was more competitive than yellow nutsedge in nonamended soil and the competitiveness of tomato further increased at the expense of reduced yellow nutsedge growth in wild radish–amended soil. Bell pepper was less competitive than yellow nutsedge in nonamended soil, but in wild radish–amended soil, bell pepper held a competitive advantage over yellow nutsedge. In addition, yellow nutsedge tuber production was reduced as much as 88% when soil was amended with wild radish, and tuber weight in nonamended soil was 0.32 g tuber⁻¹ compared with 0.05 g tuber⁻¹ in wild radish–amended soil. This research shows that competitiveness of tomato and bell pepper is increased over yellow nutsedge when soil is amended with wild radish, in addition to reducing yellow nutsedge tuber production and size.

Nomenclature: Wild radish, Raphanus raphanistrum L. RAPRA; yellow nutsedge, Cyperus esculentus L. CYPES; bell pepper, Capsicum annuum ‘SXP 0990’; tomato, Lycopersicon esculentum Mill. ‘Sunny’.