甘蔗赤斑病的严重度与产量损失的关系

在田间自然发病条件下 ,比较粤西 10个甘蔗生产品种甘蔗赤斑病的发病程度与产量损失率。结果表明 :甘蔗品种间的发病程度和产量损失均有明显差异。增施氮肥后 ,甘蔗赤斑病严重度增加 ,但对产量的影响则因品种而异。在单株测定 7个甘蔗生产品种的病害严重度与产量损失的关系中获知 :用来衡量病害严重度的病级与产量损失之间有十分密切的关系 ,从而建立了病级 ( x)与产量损失率 ( y)之间的回归方程 :y=4 .4 86x- 1.4 12。

The relationship between yellow spot disease and yield loss of sugareane cultivars

Ten sugarcane cultivars were tested under field conditions in the west area of Guangdong for susceptibility to sugarcane yellow spot disease and for the yield loss. The results showed that both susceptibility and yield loss were obviously different among tested caltivars. The disease severity increased with the increasing application of nitrogenous fertilizer, but its influence on yield loss varied with cultivars. After analysing the relationship between disease severity and yield loss of 7 sugarcane cultivars, it was showed that there was a close possitive relationship between disease index and yield loss. A regression equation was established as following: y=4.486x-1.412. Where y is yield loss and x is disease index.