Influence of Inorganic N Fertilizer on Plant Characters, Yield Generation and the Incidence of Yellow Stem Borer Scirpophaga Incertulas, Walker in the Field of Local Scented Paddy Cultivar Tulaipanji

To determine the effect of inorganic N fertilizer on the incidence of yellow stem borer (YSB), Scirpophaga incertulas Walker and on grain yield, yield attributes and bio-chemical characters of local paddy cultivar Tulaipanji, a field experiment for three consecutive years (2007-2009) was carried out by randomized block design in pesticide untreated field. Treatments comprised of seven different dose of inorganic N fertilizer viz 20,40,60,80,100,120,140 kg/ha respectively. Field with no fertilizer application was considered as control. In all the cases higher the doses of inorganic N fertilizer, higher would be the incidence of adult YSB population and accordingly the extent of damage was intensified. Incidence of dead heart (DH) and white head (WH) was 175.74% and 206.72% higher than the control field when the field was fertilized by 140 kg N/ha. Yield attributing characters differed considerably among the treatments. Maximum panicle length (1.71cm), Effective tiller number/ hill (62.01), filled grain number/ panicle (66.12), tiller number/hill (11.27), leaf number/hill (48.11) and leaf width (9.11 mm) was noted when the field was fertilized with 100 kg N. But no significant improvement of yield attributing characters except the number of filled grain number/ panicle was noted when the dose of fertilizer was increased after 100 kg N/ha. Insignificant variation of grain amylose and protein content, total phenol and ortho-dihydroxy phenol (OD phenol) amount under different fertilizer treatment was noted. Plant moisture content, however, was increased as the dose of N fertilizer was improved. Field application of 100 kg N/ha is thus suggested for Tulaipanji cultivation.