Abstract
A field study was conducted at the National Cereals Research Institute, Badeggi (9°04 N, 6°7 E), Niger ia
in 2007 and 2008 to compare the weed competitiveness and yield of inter- and intra-specific upland rice
(Oryza sativa L.) under different weed control practices. The trial was laid out in a split-plot and
arranged in a randomized block design with the two varieties of rice NERICA 1 (inter-specific) and
FARO 46 (intra-specific) assigned to the main plot, while seven weed control treatments (hoe weeding
once at 25 or 45 days after sowing (DAS), twice at 25 and 45 DAS, thrice at 25, 45 and 65 DAS,
application of 3,3-dichloropropionanilide+2,4-dichlorophenoxy acetic acid (orizo plus® by Candel) at 3.5
kg a.i ha-1 at 25 DAS, hoe weeding at 25 DAS followed by orizo plus® at 3.5 kg a.i ha-1 at 45 DAS and a
weedy check (control)) constituted the sub-plots. The treatments were replicated three times. The
results indicated that the rice variety NERICA 1 had better weed suppression ability and higher grain
yield (3.1 t ha-1) than FARO 46 (2.4 t ha-1). Weed control was better when hoe weeding was done thrice
and twice and hoe weeding at 25 DAS followed by application of orizo plus® at 45 DAS, in that order,
than other treatments. It is concluded that inter-specific NERICA 1 was more weed suppressive and
produced greater grain yield than its counterpart.
Key words: Weed competitiveness, inter- and intra-specific upland rice, weed control practices, grain yield.
