# 벼의 생육단계별 벼멸구 피해가 수량에 미치는 영향

• Lee Joon Ho (Department of Agricultural Biology, College of Agriculture, Seoul National University) ;
• Hyun Jai Sun (Department of Agricultural Biology, College of Agriculture, Seoul National University)
• 이준호 (서울대학교 농과대학 농생물학과) ;
• 현재선 (서울대학교 농과대학 농생물학과)
• Published : 1983.12.01
• 76 12

#### Abstract

This study was carried out to analyst the damage due to the brown planthopper, Nilapalvata lugens Stal, at different stages(maximum tillering, booting, heading, and milking) of rice. The results are as follows: The population density of the migrating and the first generations of the brown planthoppers seemed not to be large enough to cause significant effects on the plant height and the number of tillers, while the second and the third generations caused significant reduction in 1000 grain weight(Yl) and the filled grain percentage$(Y_2)$. They were very closely related to the population density(X) of tile second generation of the BPH; $$Y1(g)=25.602-0.0213X(r=-0.5205^{**})$$ $$Y2(\%)=76.97-0.1370X(r=-0.4820^{**})$$ The relationship between rice yield (Yg) and the accumulated total density (X) of BPH per hill by the time of harvest; $$Y(g)=24.694-0.0576X(r=-0.6959^{**})$$ Since the source of the outbreak BPH is the first generation, it nay conclude that the detailed information on the population status of the first generation; density, age components, ratio of the brachypterous form, are very important in relation to management of the pest.