Comparative Weed Density Studies in Irrigated Carrot (Daucus carota L.) Potato iSolanum tuberosum L.) and Wheat (Triticum aestivum L.) in Sokoto-Rima Valley, Sokoto State, Nigeria

摘要

A survey of weeds commonly found in irrigated carrot (Daucus carota L.) potato (Solanum tuberosum L.) and wheat (Triticum aestivum L.) in Sokoto Fadama (latiide 13deg 01sin N and longitude 5deg 15sin E) was carried out during 2001/2002 and 2002/2003dry seasons. A total of 38 major weed species were identified. Broad leaved weeds had the highest fi-equency (24 species) followed by grasses (11 species) and sedges (3 species). Highest density and proportions of most weeds species were found in carrot, followed by potato and only very few in wheat. Wild rice (Oryza longistaminata A. Chev and Roehr) and Panicum subalbidum (Kunth) were the grasses that occurred in all the three crops in both seasons. The broad leaved weeds that were common to all the three crops were Amaranthus viridis L., Cleome, rutidosperma (DC), Ipomoea aquatica (Water spinach) Forsk. Melochia cochorifolia L. Phyllanthus amarus (Schum) (common purslane) and Portulaca oleracea (L.). Amaranthus viridis L. was the most frequent weedin all the crops during both seasons.