Growth and yield losses of direct seeded rice (Oryza sativa l.) as affected by major dominant weeds in Chhattisgarh plains: A review paper

Abstract

Although weeds causes serious yield losses in agriculture, many studies have been conducted on the relationship between weeds and yield loss in direct seeded rice. Major weeds found in Chhattisgarh plains are Echinochloa colona, Echinochloa crus-galli, Ischaemum rugosum, Oryza sativa (weedy rice), Leptochloa chinensis, Paspalum distichum among the grasses. Cyperus iria, Cyperus difformis, Cyperus rotundus, Fimbristylis miliacea among the sedges and Monochoria veginalis, Eclipta prostrate, Commelina benghalensis, Cynotis axillaris, Ceasulia axillaris, Alternanthera triandra among the broad leaved weeds. Weeds are most serious biological constraints in direct seeded rice, because weed emergence coincide with the seedlings due to which the productivity is often lower. Weeds being hardy and having profuse root and shoot growth habit, grow faster than rice and thereby check the growth of rice by severe competition in critical crop weed competition period Direct yield loss has been estimated to the range from 16-86% depending on type of rice culture, cultivars, weed species and density, cropping season, plant spacing, fertilizer rate, duration and time of weed infestation and climatic and environmental conditions.