Fipronil Rice Literature Study

BIO-EFFICACY OF FIPRONIL 200 SC FOR THE CONTROL OF LEAF FOLDER AND YELLOW STEM BORER IN RICE
K. Vasanta Bhanu*, A. Vishnuvardhan Reddy and P.V. Satyanarayana
Andhra Pradesh Rice Research Institute and Regional Agricultural Research Station, Maruteru-534 122, West Godavari District, Andhra Pradesh, India
*E-mail: [e-mail];
ABSTRACT
Field experiments were conducted during Kharif 2012 2013 to field evaluate the field efficacy of fipronil 200 SC at different dosages i.e. 30, 40 and 50 g a.i./ha in comparison with treated and untreated checks. The results indicated that in both the seasons, all the dosages of fipronil 200 SC significantly reduced the incidence of leaf folder along with the treated checks viz., fipronil 80 WG and fipronil
Approximately 52% of the global production of rice is lost annually owing to the damage caused by biotic stress factors, of which 21% is attributed to the attack of insect pests (Yarasi et al., 2008). Rice is infested by more than 100 species of insects and mites and about 20 of them are considered to be major economic significance. Among the serious insect pests, rice leaf folder (RLF), Cnaphalocrosis medinalis (Guenee) and yellow stem borer (YSB), Scirpophaga incertulas (Walker) are considered to be major lepidopteran pests causing significant yield loss. Rice leaf folder, earlier considered to be minor pests have gained the status of major pests with the wide spread cultivation of high yielding varieties and the accompanying changes in cultural practices. Leaf folder larva fastens the edges of the leaves, folded them longitudinally and feed on green matter. A damaged leaf produce white streaks, become membranous and ultimately reduces the photosynthetic activity of the plant. The extent of loss may extend up to 63 to 80 percent depending on agro-ecological situations (Rajendran et al., 1986). Yellow stem borer larvae after emerging from the egg mass enters in to the tiller and feed inside it and damages the central whorl, resulting into dead heart during vegetative stage and white ears at
The differences in per cent dead hearts among the treatments were not significant before first spray. At five days after the first spray, except chlorpyriphos 20 EC @ 250 g a.i./ha (3.04), remaining insecticide treatments recorded significantly lower % of dead hearts than untreated control (3.38). Among them, fipronil 5 SC @ 50 g a.i./ha recorded lowest per cent of dead hearts (0.84) and on par with all the dosages of fipronil 200 SC, fipronil 80 WG @ 50 g a.i/ha and L-cyhalothrin 4.9% CS @ 12.5 g a.i./ha.
The difference in % dead hearts among the insecticide treatments was significant at ten days after first spray also. Significantly lowest % dead hearts was observed in fipronil 200 SC @ 40 g a.i. /ha (0.64) and was on par with fipronil 200 SC @ 30 g a.i. /ha (0.89) and fipronil 5 SC @ 50 g a.i./ha (0.90). These were followed by L-cyhalothrin 4.9% CS @ 12.5 g a.i./ha (1.01), fipronil 200 SC @ 50 g a.i. /ha (2.60) and fipronil 80 WG @ 50 g a.i. /ha (2.60) and were superior to check insecticide viz., chlorpyriphos 20 EC @ 250 g a.i./ha (3.35) and untreated control