Abstract: A field experiment was carried out to investigate the effects of nitrogen and silicon nutritions on rice blast occurrence on a traditional glutinous rice variety Huangkenuo under intercropping with japonica variety chujing 26.Under the normal nitrogen supply(225 kg/hm²N),the rice biomass aboveground and grain yield under intercropping increased by 15.8% and 20.8%;nitrogen content in culm and leaf reduced by 35.5% and 14.1%;silicon content in culm and leaf decreased by 13.9% and 8.8%,and severity index of leaf blast and panicle blast decreased by 10.0% and 27.7% in Huangkenuo,respectively.Nitrogen content in rice plant at higher nitrogen level(450 kg/hm²N)was higher than that at normal nitrogen level.As a result,the severity indices of leaf blast and panicle blast in Huangkenuo were increased.There was a significant positive relationship between plant nitrogen content and rice blast incidence,the correlation coefficient ranged from 0.820^**to 0.968^**.The plant silicon content with silicate application was higher than that without silicate application.Consequently,the severity index of panicle blast was decreased.There was a significant negative relationship between silicon content in culm and rice panicle blast occurrence,the correlation coefficient was from-0.969^** to-0.707^*.The lower plant nitrogen content under intercropping could partially explain the rice blast control under diversified cultivation.

Key words: rice, intercropping, nitrogen nutrition, silicon nutrition, rice blast, relationship

摘要： 通过田间试验，研究了水稻黄壳糯在间作条件下氮硅营养对稻瘟病发生的影响。 在常规施氮条件下（225 kg/hm2N），与单作相比，间作提高水稻地上部生物量约15.8%，籽粒产量提高20.8%；降低植株茎、叶氮含量35.5%和14.1%，茎、叶硅含量降低13.9%和8.8%；对叶瘟和穗瘟防效为10.0%和27.7%。增加氮肥施用量（450 kg/hm2N），植株中氮含量显著提高，叶瘟和穗瘟病情指数明显上升。茎叶氮含量与叶瘟和穗瘟发生呈显著正相关，相关系数为0.820**～0.968**。施硅能促进水稻对硅的吸收，降低穗瘟发病的严重程度，茎中硅含量与穗瘟的病情指数呈显著负相关,相关系数为-0.969**～0772*。间作水稻植株中氮含量降低是生物多样性控制稻瘟病发病的原因之一。

关键词: 水稻, 间作, 氮营养, 硅营养, 稻瘟病, 相关性