Analysis And Valuement For Regrowth Characteristic Of Alfalfa(Medicago Sativa L.) Individual Plants

Regrowth characteristic in an important characteristic in perennial grasses and the majority of perennial grasses can regenerate after cutting or grazing . Alfalfa with better or poorer regrowth characteristic is the sign of its living potential and indexes of its economical performance.In this paper, Zhongmu No.2 different individual plants had been conducted in two trial fields which were seated in Beijing and Zhong jie farm in Huang hua city of Hebei province. These mensurated indexes including plant height, regrowth rate , regrowth branch number, regrowth shoot weight , regrowth intensity and Dry Weight per plant were used for analyzing and evaluating their regrowth characteristics. The following were the chief results of this research:1. There was a greater variation for first stubble characteristic in alfalfa individual plants and variance coefficient of Dry Weight per plant ,branch number,shoot weight is greater and it's variance coefficient scope respectively was 27.74% ~ 36.13%, 28.48% ~ 29.14%,24.09% ~ 29.14% but variance coefficient of regrowth height and regrowth rate was smaller with 8.97% ~ 11.94%,11.23% respectively.2. Greater variance coefficient of regrowth characteristic occured in regrowth shoot weight , regrowth total Dry Weight, regrowth intensity ,regrowth branch number and the scope of variance coefficient was 26.08%～39.34%,26.05%～39.23%,30.94～33.31%,28.69%～31.64% respectively . The variance coefficient of regrowth rate and regrowth height was smaller with 13.15%,9.05%～10.20%3. Correlation analysis showed that a positively significant correlation for plant height, branch number, shoot weight and plant Dry Weight and. There was negatively correlation for shoot weight and branch number, with branch number increase and shoot weight decrease .4. The same regrowth characteristics showed very positively significant correlation between 2nd and 3rd stubble , 2nd and 4th stubble excepting regrowth height and regrowth shoot weight .5. There was a very positively significant correlation for each regrowth characteristic and regrowth Dry Weight per plant excepting regrowth height.6. Regrowth height had the highest change scope after cutting within 14 days, after 14 days regrowth rate changed slowly, after cutting for 7 days , regrowth rate of higher regrowth yield plant was bigger than lower regrowth yield plants and their height scope was 10.3～23.7cm, 5.1～18.4cm in 2nd stubble and 6.3～27.7cm , 2.7～12.7cm in 3rd stubble respectively.7. Ratio about each stubble yield accounted for toal yield in whole year was that the 1st stubble and the 2nd stubble had higher ratio with 40%～53%,23%～36%,respectively, while the 3rd and 4th stubbles had lower ratio with 18%～19%,and 6%。8. In each stubble, 100 individual plants were selected separately from higher productive, middling, and lower productive plants and their yield was compared in four stubbles, higher yield single community exceeded 19.96%, 16.93%, 21.74%, 16.77% respectively than middling yield plants while 65.69%,65.05%,98.21%,91.88% than lower yield's plants.9. Take the individual plant's regrowth plant height, regrowth rate, regrowth branch number,regrowth shoot weight , regrowth intensity, regrowth Dry Weight per plant as comparision sequence , 96 alfalfa individual plant's regrowth characteristics and they were comprehensively compared and evaluated and 30 individual plants with better regrowth charateristic had been selected through gray related theory. And regrowth plant height, regowth branch number, regrowth shoot weight , regrowth intensity and regrowth Dry Weight had been taken as mensurated indexes, 341 alfalfa individual plant's regrowth characteristics were comprehensively compared and evaluated through gray related theory and made the sequence for gray related degree , and 100 individual plants with better regrowth characteristics were selected.10. The mean value of regrowth characteristics including height, regrowth branch number, regrowth shoot weight, regrowth intensity, and regrowth Dry Weight per plant of selected 100 individual plants in Zhongjie farm were 66.8cm,138 , 1.32g, 65.21%, 563.6g, exceeded the average value of initial plant community respectively 2.52%, 22.32%, 10.34%, 23.27%, 30.33%.11. 100 selected individual plants were divided into three groups through cluster analysis method and their regrowth characteristics were strongest , more stronger and middling level.