*资助项目：公益性行业（农业）科研专项（200803003）。
** 通讯作者，Email: liufang@yzu.edu.cn
收稿日期：20110810，接受日期：20110825Effects of rice varieties and nitrogen fertilizer application rates on the
occurrence of the brown planthopper, Nilaparvata lugens under
field conditions JIANG Tao1ZHAO JunLing1CHENG JianJun1 XU Shuai1SU Wen1
BAO ShanWei2LIU Fang1**
（1. College of Horticulture and Plant Protection, Yangzhou University, Yangzhou225009, China;
2. Agricultural Technology Extension Center of Rugao, Jiangsu226500, China）
AbstractThe effects of rice varieties and nitrogen fertilizer application rates on the occurrence of the brown planthopper (BPH), Nilaparvata lugens (Stl), were studied under field conditions in 2010. The results indicate that the abundance of BPH on the rice varieties Nanjing 44, Ningjing 1hao, Bing 123 and Huaidao 9hao were significantly lower than that on TN1 during August 10 to September 10. The abundance of BPH on Nanjing 44 was significantly higher than on Ningjing 1hao, Bing 123 and Huaidao 9hao during September 20 to 30. The abundance of BPH on rice plants treated with 250 kg /hm2 effective nitrogen was the highest, whereas that on rice crops with no nitrogen treatment was the lowest. The interaction between rice variety and nitrogen fertilizer application rate had little effect on the occurrence of BPH. The amounts of oxalic acid and flavonoids in Nanjing 44, Ningjing 1hao, Bing 123 and Huaidao 9hao were not significantly higher than those in TN1, and no significant difference in the amount of free amino acids in BPH feeding on these different rice varieties was found. Therefore, the relatively high abundance of BPH on TN1 was not related to oxalic acid or flavonoid levels in rice plants, or to the amount of free amino acids in the insects’ bodies. The amount of oxalic acid and flavonoids in rice plants increased with nitrogen fertilizer application rate. The amounts of glycine, valine, isoleucine, leucine and lysine in BPH feeding on rice plants with high nitrogen application were significantly higher than those to feeding on plants to which no nitrogen fertilizer had been applied. These results suggest that the relatively high abundance of BPH on rice plants treated with high levels of nitrogen fertilizer was caused by the increased level of oxalic acid and flavonoids in such plants, and the relatively high amounts of free amino acids that the insects obtained from them.
Key wordsNilaparvata lugens, rice variety, nitrogen fertilizer application rate, field population