南方水稻黑条矮缩病对水稻产量损失及测报因子的初步研究

南方水稻黑条矮缩病是近年来在我国南方稻区新发生的一种重要病毒性病害.本文通过测定水稻品种‘T优272'上该病不同发病程度所对应的产量损失,分别建立了以病丛率、病株率与产量损失率之间的线性回归方程y=1.0270x1-1.363 4(R=0.999 6)、y=1.050 9x2-0.450 8(R=0.999 2).依据回归方程及南方稻区水稻生产实际情况,南方水稻黑条矮缩病在中稻上经济允许水平与成灾水平因子是病丛率4.79％与30.54％或病株率3.81％与28.98％,晚稻上经济允许水平与成灾水平因子分别是病丛率5.06％与30.54％或病株率4.08％与28.98％,中晚稻的绝收水平因子是病丛率79.22％或病株率76.55％.

Preliminary study on rice yield loss caused by Southern rice black streaked dwarf virus disease and the forecasting factors related with the disease

A new rice disease caused by Southern rice black-streaked dwarf virus(SRBSDV) has widely occurred in southern China in recent years.In this study,the regression equations between diseased hill rate or diseased plant rate and yield loss rate,y=1.027 0x1-1.363 4(R=0.999 6) and y=1.050 9x2-0.450 8(R=0.999 2),were obtained via determination of the rice varieties of ’T You-272’.Based on the results obtained and the actual situation in rice production in South China,the economic threshold and the factors causing outbreak of SRBSDV were obtained,reaching 4.79%/30.54%(diseased hill rate) and 3.81%/28.98%(diseased plant rate) for middle-season rice,and 5.06%/30.54%(diseased hill rate) and 4.08%/28.98%(diseased plant rate) for late rice.Meanwhile,the factors of zero harvest for middle-season rice as well as late rice were calculated,which were 79.22% and 76.55% against diseased hill rate and diseased plant rate,respectively.