Analysis on the differences of photosynthetic efficiency ofmultifolilate and trifoliolate alfalfa in each cutting

In order to determine the factors associated with utilitization of luminous energy and water as well as their effects on hay yield, leaf net photosynthesis rate, transpiration rate, and other physiological and ecological factors of multifolilate and trifoliolate alfalfa were measured with a LI6400 portable photosynthesis system at the beginning of flowers of first to third cutting. including leaf temperature (Tl), stomatal conductance (Ls) and internal CO2 concentration (Ci), photosynthetic available radiation (PAR), air temperature (Ta), CO2 concentration in field (Ca), Hay yield of multifolilate alfalfa was significantly higher than trifoliolate alfalfa (P0.01), which was influenced by photosynthetic pigments, net photosynthesis rate (Pn), transpiration rate (Tr), internal CO2 concentration (Ci), stomatal limitation (Ls), light use efficiency (LUE), and water use efficiency (WUE). There were significant differences between the two type of alfalfa in photosynthetic characteristics. The higher photosynthesis, photosynthetic pigments and light use efficiency of multifolilate alfalfa resulted into greater hay yield.