Agronomic traits,key enzyme activities of carbon and nitrogen metabolism and yield of three hybrid rice varieties of panicle-rich type(Mingliangyou 143),large-panicle type(Xiangliangyou 900)and medium-panicle type(Fengliangyou 4)under four fertilization levels(pure N rates 0,150,225,300 kg/hm2)were studied to expound the effects of fertilization level on the growth and yield of panicle-rich hybrid rice.The results showed that with the increase of fertilization level,the yield of the three varieties increased simultaneously,and the increase of fertilization level promoted the number of effectiv...
