Effect of varieties and weeding regimes on weed and performance of

Abstract

A Field trial was conducted at the aerobic rice experimental field of the NationalCereals Research Institute (NCRI), Badeggi, Nigeria (9 ° 04 N and 6° 7 E)in 2007 and 2008 wet seasons to determine the weed competitiveness andperformance of inter ‐ and intra‐specific aerobic rice (Oryza sativa L.) varietiesunder seven weeding regimes. The trial was laid out in a split plot designwith the two varieties of rice (NERICA 1 as inter ‐specific and FARO 46 asintra ‐specific) assigned to the main plot while seven weeding regimes (hoeweeding at 25, 45, and 65 days after sowing (DAS), 25 DAS, 45 DAS, 25 and45 DAS, application of 3’,3’ ‐ dichloropropionanilide /2, 4 – Dichlorophenoxyacetic acid (orizo plus R) by Candel Company Ltd. at 3.5 kg active ingredient(ai )ha ‐1 at 25 DAS, hoe weeding at 25 DAS followed by orizo plus at 3.5 kg aiat 45 DAS and weedy check) constituted the sub – plots. The treatmentswere replicated three times in a split plot design. From the results, interspecificvariety (NERICA1) had better weed suppression ability with highergrain yield of 3.1 t ha ‐1 than the intra‐specific variety (FARO 46). Weed controlwas better when hoe weeding was done at 25, 45 and 65 DAS or 25 and45 DAS and at 25 DAS followed by orizo plus at 45 DAS than in other treatments.However, hoe weeding at 25, 45 and 65 DAS gave significantlygreater grain yield than other treatments. Although economic yield was obtainedfrom hoe weeding at 25 DAS followed by orizo plus at 45 DAS.