Disease incidence related closely with not only varieties and meterological condition, but cultivation practices such as irrigation, sowing date, sowingdensity, sowing method and so on.
发病程度除与品种、气象条件有关外，还与灌水，播种时期，密度，播种方法等栽培措施关系密切。
2
The results indicated that plant height, leaf age, LAI and accumulation of dried matter existed difference under different sowingdensity, especially sowing densities had the great effects on yield.
结果表明，不同种植密度下株高、叶龄、LAI和干物质积累均存在差异，且产量受种植密度影响较大。
3
The suitable planting density and time of sowing are favor of optimum use of soil water and improving water use efficiency, and make potato increasing its output.