杂交水稻黑条矮缩病的为害及防治指标初探

Occurrence of Black-streaked Dwarf Viral Disease of Hybrid Tice and Its Economic Threshold

根据1998-2003年杂交水稻黑条矮缩病发生为害损失与防治指标研究,测定了杂交水稻不同组合、不同生育期的发病率,以及秧苗期与大田期的侵染机率,分析了杂交水稻黑条矮缩病前后作发病率关系:M=1.6822m+0.1049,以及株发病率(M％)与产量损失率(Y％)的关系:Y=0.9776M-0.1935;阐述了灰飞虱不同虫量(X)与发病率和产量损失率(Y％)的关系:秧苗期为Y1=12.1841X1-1.0784,大田前期为Y2=4.5159X2-0.4620。在拟定经济允许损失水平的基础上,提出杂交水稻秧苗2-5叶期和大田初期为防治适期,并制定杂交水稻黑条矮缩病的策略性防治指标为前作穗期防治的黑条矮缩痛株发病率1.0％,制定秧苗期防治指标为带毒灰飞虱0.15只／0.11m2、大田初期防治指标为带毒灰飞虱4000只／667m2(百丛带毒灰飞虱20只)。经应用验证,与实际基本吻合。

Based on experiment between occurrence of black-streaked dwarf viral disedse of hybrid rice (RBSDV) and its economie threshold in 1998-2003. The results showed that incidence of RBSDV was tested during different hybridized combination and growth stage of hybrid rice, and infection probability in seeding stage and vegetative stage on hybrid rice ,and relationship of incidence of last stubble (m%) and next stubble(M%) and yiled loss rate(Y%) were analysed, the model are as follows M=1.6822m+0.1049 and Y=0.9776M-0.1935 .Relationship of various small brown planthopper(SBPH) (Laodelphax striatellus) population density (X) and infection rate and yiled loss rate (Y%) was invesligated , the model are as follows Y1=12.1841X1-1.0784 in seeding stage and Y2=4.5159X2-0.4620 in the early days of field stage . It was provided that control optimal time were 2 nd-5th leave age in seeding stage and early tillering stage in the field stage. On economical injuring level the economic threshold was determined as the diseased rate reaching 1.0% last stubble and 0.15 viruliferous SBPH vector /0.11m2 in seeding stage and 4000viruliferous SBPH vector /667m2 (20 viruliferous SBPH vector/100 clusters) in early tillering stage on hybrid rice.