Study On Yield And Photosynthetic Character Of Four Alfalfa Varieties

Yield and Photosynthetic Character of four different year's alfalfa (Medicago sativa L.) varieties were researched at the LinXi county of ChiFeng city Inner Mongolia in 2007. The result shows:1. The yield and height of four different year's alfalfa varieties had the most significantly positive correlations, The yield and height of the first cutting was superior to the second cutting. Alfalfa provide the strongest yield in the second year, the first year of production capacity was the weakest. The dry total yield of Gold Empress and Rangelander were highest in the second year.2. The high regrowth performance of four different year's alfalfa varieties was best in the fourth year, it was worst in the first year. The high regrowth performance of Rangelander was the best in the fourth year.3. In the flowering stage, the diurnal changes of Pn were single-peaked curves wicth was the Rangelander of the third year and Algonquin of the fourth year, other alfalfa varieties diurnal changes of Pn were double-peaked curves, and had midday depression of photosynthesis, in addition to four different alfalfa varieties of the first year, Rangelander and Algonquin of the second year, the second peak of others alfalfa varieties was lower than first peak.4. The alfalfa varieties that had midday depression of photosynthesis in the flowering stage, in addition to lunch-time Pn is lower due to non-stomatal fators which were Aohan of the second and third year, Gold Empress of third year and Rangelander of the first year,other alfalfa varieties were due to stomatal fators.5. In the alfalfa flowering stage, PAR, Tr, Ls and Ci were major elements influencing diurnal changes of Pn. The major elements influencing were different of different year and different alfalfa varieties.6. In the alfalfa flowering stage, Average of diurnal Pn is the larger which were Rangelander and Gold Empress of the second year, Algonquin of the second year and the third year. Average of diurnal Pn in alfalfa had no correlations with chlorophyall; Pn in alfalfa had significant positive correlations with yield, other indicators of photosynthesis had small correlation coefficient with yield, they were not sifnificant.