Effects on dynamic growth and yield by different stubbles of alfalfa cradled

Effects of different stubbles cradled on dynamic growth and yield in four alfalfa varieties were investigated in the area of Yellow River Delta during 2002. The results showed that the stubble's branch quantities with the cradling increased were more than the first stubble's, especially more increased after the second stubble. The branch quantities of four alfalf varieties cradled got to the peak at the 18th to 22nd days and then decreased . The highest daily growth appeared after the first stubble and decreased subsequently. Alfalfa SD003's height was increased during the second stubble, while the other three breeds, decreased. So it was with the dry mass. Accordingly, to 96S016 and Zhongmu No. 1 of lower yield we can advance the harvesting time of the second stubble by 5 to 10 days, while to alfalfa SD003 we can appropriately delay the first cradle s harvesting date.