摘要
本试验在3种不同的种植密度下,分期调查了马铃薯主栽品种Mira和783-1在田间的块茎大小分布。结果证明,块茎生长发育期间其大小分布为一负指数曲线形式,并可用数学模型y=N(e^(-λbn^(-1))-e^(-λbn))来表示(式中y为块茎重量等级n的块茎个数,N为单位面积的块茎总数,λ为块茎平均重量的倒数,b为块茎重量等级的上限)。即在一个块茎群体中,块茎数目以30g以下的小块茎为多,随着重量级别的增加,其数目逐步减少。高密度增加了小块茎的数目及其比例从而导致块茎的平均重量下降。统计分析表明,模型预测值与实际观测值无显著差异。根据上述模型,块茎的大小分布主要取决于单位面积上的块茎总数及块茎平均重量这两个参数。由于种植密度与块茎数目、光能截获量与块茎产量之间存在着显著的相互关系,因此根据对块茎大小的需求,该模型可帮助确定适宜的种植密度与收获晚期,来达到控制块茎大小的目的。
Potato tuber size distribution of cvs. Mira and 783-1 was investigated regularly under three plant densities in the experiment field. The results showed that size distribution during tuber growth followed a negative exponential curve which could be described with a mathematical model of Y=N(e^(-λbn-1)-e^(-λbn) (Ynumber of tubers of size category n, N- total number of tuber per unit area, λ-reciprocal of mean tuber weight, and b-up per limit of tuber size category), i. e. within a population the number was larger with the tubers less than 30g and decreased as size grade increased. High plant density promoted the production of small tubers and their proportion, hence the reduction of mean tuber weight. The statistical analysis indicated that the data of tuber number observed fitted in well with the predicted values.According to the model, tuber size distribution was mainly controlled by two parameters, total number of tuber per unit area and mean tube rweight. Since there were remarkable relationships between plant density and number of tuberand between intercepted radiation and tuber yield, the model was capable ofchoosing a suitable plant density and harvesting time based on the productiondemand for a particular tuber size, to achieve the goal of tuber size control.
出处
《马铃薯杂志》
1991年第3期141-147,共7页
Chinese Potato Journal
