稻瘟病为害损失研究

采用人工接种诱发和药剂控制相结合的方法，造成小区间稻叶瘟病和稻穗瘟的发病梯度系统监测病情，收获期结合病情程度进行单株考上区测产，并分别建立了依据稻叶瘟病，稻穗瘟病和二者综合的损失估计模型。就稻叶瘟病地水稻有效穗、穗粒数、千粒重和精米率的影响作了定量研究。另外，地稻穗瘟病在不同品种，不同侵染发病时间以及不同发病部位的为害影响进行了初探。结果表明，稻穗瘟病的为害程度在不同品种上存在一定差异，与侵染发病

A STUDY ON YIELD LOSS CAUSED BY RICE BLAST

The experiment of yield loss was conducted in a farm in Huangshan, Anhui Province. The disease difference of rice leaf blast and neck blast among plats was obtained by means of artificial inoculation in combination with fungicide control of the disease. Systematic monitoring of the development of the disease and the yield per single plant as well as per plot were measured during at harvesting period. Based on the above results,a model of yield loss caused by leaf last,neck blast and the integration of them have been set up, respectively. Meanwhile, the effect of rice leaf blast on the number of effective heads,number of grains per head, the weight of one thousand grains and percentage of whole rice grains were also investigated. The effect of rice neck blast on different cultivars, time of infection and access, and the diseased part of the rice plants were studied preliminarily. The results show that there was some difference in damage caused by rice neck blast among cultivars. The difference has close relation to the time of infection and access and the diseased parts.