旱作马铃薯根系拉力与冠层覆盖度对块茎膨大及产量的影响

马铃薯根系和冠层是形成块茎产量的主要因素。根系拉力与冠层覆盖度及块茎产量的均呈极显著正相关，即根系拉力越大，冠层越旺盛，块茎产量越高。冠层覆盖度与块茎膨大速度及块茎产量亦呈极显著正相关。冠层的形成随株龄的增加呈曲线上升，品种不同上升的程度亦不同。块茎形成期因品种不同而各异。块茎膨大速度从蕾期至成熟均呈直线上升趋势，随品种不同而有差异。因此，根据马铃薯根系拉力和冠层覆盖度的量变数据呆预测马铃薯块茎产

The Effect of Root Pulling Resistance and Canopy Cover Degrees on Tuber Expansion and Yields of Dryland Tillage Potato

Root system and canopy of potato are main factors for forming tuber yields. Root pulling resistance had a outstanding positive linear correlation to canopy cover degrees, i. e., the larger root pulling resistance is, the exuberanter canopy and the higher tuber yields is. Canopy cover degrees had a outstanding positive linear correlation to tuber expansive speeds. The canopies increase along with the plant age. Different varieties were various canopies. The tuberization stage were various due to different varieties. Tuber expansive speeds had a raise of straight line from the squaring to maturity. Different varieties had different expansive speeds. Therefore,according to quantitative datum of canopies, we can predict high or low yields of potato tuber, and it can also become an hoportant scientific basis for selection high yields varieties. The results indicated that varieties of good economic characters, strong drought resistance and high yields were Wumeng 851, Xishu 1. They were suitable to planting in the dry areas. But Zihuabai, Bashu 10 etc. infected late blight easily. They can not be spreaded in large areas.