Determination of rainbow efficacy as post emergence herbicide in lowland rice

Abstract

A Randomised Complete Block Design experiment was carried out in three consecutive years (2005, 2006 and 2007) at the experimental site of National Cereals Research Institute, Badeggi, to evaluate the efficacy of Rainbow as a post emergence herbicide in lowland rice. Rainbow has penoxsulam as its active ingredient. FARO 52 was the test crop and the rate of Rainbow used were 1.0, 1.25, 1.50l/ha compared with a check chemical Orizoplus^R at 5l/ha. Orizoplus^R is made up of Propanil and 2, 4 – D Amine. Two hand weeding at 21 and 42 days after transplanting and weedy plot were also included as part of the treatments in a plot size of 5m x 10m and three replicates. It was observed that Rainbow was not phytotoxic to rice when applied on rice field indicating that it can be safely used in rice field without causing injury to the rice plant. The three years’ pooled result of the trial showed that application of Rainbow at 1.25 – 1.50l/ha is good for weed control in lowland rice field which will also result into higher yield.