7个紫花苜蓿品种在九华沟流域生长性状的比较

Comparison of the growth traits of seven varieties of alfalfa in Jiuhuagou watershed

摘要:

【目的】 紫花苜蓿（Medicago sativa）品种和生长性状影响其产量，明确引进紫花苜蓿品种产量形成与生长特性间的关系，为紫花苜蓿生产提供理论参考。【方法】 在以紫花苜蓿为主要栽培牧草的黄土高原雨养农业区陇中九华沟流域，对7个紫花苜蓿品种生长特性及产量进行分析。【结果】 7个紫花苜蓿品种产草量和生长性状均差异显著（P＜0.05），其中Vela（VL）产草量显著高于其余6个紫花苜蓿品种（P＜0.05）。其产草量、叶干重、茎干重均比本土优势品种陇东苜蓿表现优异，分别高7.76%、 3. 93%、10. 99%。综合比较苜蓿品种生长特性，生长性状与产草量普遍呈线性和二次函数关系。紫花苜蓿产草量与株高、株高×冠幅、生殖密度、营养枝密度和分枝密度呈二次函数关系。其中株高对产草量拟合关系最好，预测公式为：y=4.3564x2-406.43x+1937 9（R2=0.904 5，P＜0.001）。【结论】 7个紫花苜蓿品种中VL是表现最好的品种，适合在试验区引种栽培，株高、叶面积指数和生殖枝数是产草量的较好预测因子，能够普遍用于紫花苜蓿产草量的预测。

Abstract:

【Objective】 Alfalfa （Medicago sativa） varieties and growth traits affect its yield，to clarify the rela tionship between yield formation and growth characteristics of introduced alfalfa varieties，and to provide reference for alfalfa production.【Method】 The study analyzed the growth characteristics and yield of seven alfalfa varieties in the Jiuhuagou watershed of Longzhong，a rain-fed agricultural area of the Loess Plateau where alfalfa is the main culti vated forage.【Result】 The seven varieties of alfalfa exhibited significant differences （P＜0. 05） in grass yield and growth traits. Among the six alfalfa varieties，VL yielded significantly （P＜0. 05） higher than the others. Its grass yield，leaf dry weight，and stem dry weight were all superior to those of the indigenous superior variety LD，with in creases of 7. 76%，3. 93%，and 10. 99%，respectively. When comprehensively comparing the growth characteristics of alfalfa varieties，it was observed that growth traits and grass yield generally showed linear and quadratic relation ships. The quadratic relationship between alfalfa grass yield and plant height，plant height x crown span，reproductive density，nutrient branch density，and branching density indicated that the above growth traits had different effects on grass yield at different growth stages of alfalfa. Among the factors analyzed，plant height showed the strongest correla tion with grass yield. The prediction equation for this relationship is y=4. 356x2-406. 43x+19 379 （R2=0. 904 5， P＜0.001）.【Conclusion】 Among the seven varieties of alfalfa tested，VL proved to be the most suitable for cultiva tion in the test area. The predictors of hay yield were found to be plant height，leaf area index，and number of reproduc tive branches，which were better indicators than other factors. These predictors can be generalized for the prediction of alfalfa hay yield.