马铃薯品种‘荷兰15号’主茎密度与植株性状及块茎产量的关系

Relationships of Main Stem Density to Plant Traits and Tuber Yield in 'Helan 15' Potatoes

在中国,马铃薯种植密度一般以单位面积播种的种薯(块)数来表示。然而,马铃薯不同于其他主要粮食作物,种薯(块)上有多个芽眼,可以长出多个主茎。每个主茎有自己的根、匍匐茎、块茎、叶和花序。因此,把单位面积的主茎数作为马铃薯种植密度更为合理。试验在大垄(90 cm)机械化栽培的条件下,明确马铃薯‘荷兰15号’主茎密度与植株性状及块茎产量的关系,通过种薯切块大小和切块种植密度的不同获得单位面积有差异的主茎数。试验采用二因素裂区设计,3次重复。种薯切块大小被安排在主区,分别设30,50和70 g共3个处理;株距被安排在副区,分别设10,15,20,25,30,35和40 cm共7个处理。单位面积的主茎数越多,单位面积的总块茎数就越多,但平均块茎重却越小。然而,主茎数与总产、商品薯产量、商品薯个数关系却不是直线的,可用二次多项式描述其之间的关系。对总产量来说,Y总产=903.278 2+63.570 9X-0.914 9X2(R2=0.759 7,P<0.000 1),当X(主茎数)在35时,Y总产有极大值2 008,即:当主茎数=35个/m2,总产量=2 008 kg/667m2。该研究结果可为‘荷兰15号’的高产栽培提供理论依据。

Planting density of potatoes in China is usually expressed in the number of seed tubers(seed pieces)planted per unit area. However, potato seed tuber(seed piece), different from seeds of other food crops, has more than one eye, and can produce multiple main stems. A single stem has its own roots, stolons, tubers, foliage and inflorescences. Thus, it is more logical to treat main stem number per unit area as a unit of population. The purpose of this research was to understand the relationships of main stem density to plant traits and tuber yield in 'Helan 15'potatoes cultivated mechanically in large ridged-row(90 cm). Various main stem numbers per unit area were attained through manipulating seed piece size and in-row spacing. The experiment was laid out in a split plot design of threereplications, with seed piece size(30, 50 and 70 g) being arranged into main plots and in-row spacing(10, 15, 20, 25,30, 35 and 40 cm) into split plots. Main stem number per unit area was positively associated with total tuber number, but negatively with mean tube weight. However, the relationships of main stem density to the total yield, marketable tuber yield, and marketable tuber number were not linear, and could be described using quadratic polynomial equations. For the total yield, Ytotal yield= 903.278 2 + 63.570 9X-0.914 9X2(R2 = 0.759 7, P < 0.000 1), and when X = 35, Y = 2 008 kg/667m2,the highest value. These results might provide theoretic basis for high-yielding cultivation of 'Helan 15' potatoes.