Weeds Density Study in Lowland Rice Production System in Northern Guinea Savanna Ecology, Nigeria

Abstract

A field trial was conducted at research farm of the irrigation research station, Institute for Agricultural Research (I.A.R), Ahmadu Bello University, Zaria located at Kadawa irrigation scheme in the Northern Guinea Savanna ecological zone of Nigeria during 2012 and 2013 wet seasons to study the density attributes of weeds in paddy rice ecology. A total of 20 and 22 weed species were identified during the 2012 and 2013 wet seasons respectively. Results obtained indicated that Cyperus Iria had the highest density, relative to other weeds, followed by Cyperusdifformis, Dactelocteniumaegyptium, Ludwigiaabyscinica and Kylingiasquamulata in 2012 while in 2013; C. iria was found to consistently be the most densely populated weed among the identified weed species during the trial. This was followed in decreasing order by Digitaria horizontalis, Echinochloacolona, C. rotundus and D. Aegyptus. The most important weed in the 2012 wet season was C.iria which was followed by C.difformis, D.aegyptium, L.abyscinica and K.squamulata while in 2013 the importance value index (IVI) revealed that the most important weed within the community was C. difformis. This was closely followed by D. horizontalis, E. colona, C. rotundus, and D. aegyptium.The most important weeds associated with the paddy crop in the study area were grasses and sedges.