Studies On Cultivation Of High Yield And Quality In Pennisetum Americanum×P. Purpureum

In this thesis, Based on the comparison of different sowing date of parents in Pennisetum americanum x P. purpureu, to present the best sowing time for parents in Pennisetum americanum x P. purpureu. And investigate the effect of four different fertilizer application levels on yield, crude protein content and nitrogen production efficiency of Pennisetum americanum x P. purpureum and the correlations of the yield and crude protein content with the fertilizer application rate and various agronomic traits were also investigated. Through the flat and Oblique cutting in two ways and three kinds of 5cm,15cm,20cm stubble height, discussed the effects of cutting patterns on Pennisetum americanum x P. purpureum height, tiller number and dead strain rateand output.with a view to lay the theoretical basis and production guidance for cultivate Pennisetum americanum x P. purpureum in a scientific way.. The results are as follows:Test 1:Parental planting period control, to achieve synchronous flowering, is the key to breeding Pennisetum ameicanum x P. purpureum. Paternal elephant grass flowering may after 100 days reproductive growth stage, can be stabilized flowering in mid-November. female pennisetum americanum need 65.6 days from sowing to flowering (Coefficient of variation 3.98%), in order to achieve synchronization with the male parent flowering it should be sown in early SeptemberTest2:The fertilizer application could significantly increase the tiller number, plant height, yield and the content of crude protein. There were positive correlations among fresh yield, hay yield, crude protein content,tiller number, plant height and the fertilizer application rate in Pennisetum americanum x P. purpureum. The fresh yield was significantly correlated with with the fertilizer application rate, the tiller number and the content of crude protein, and was highly significantly correlated with the plant height and the hay yield. The content of crude protein was correlated significantly with the fertilizer application rate. At a given range of fertilizer application, the amount of dry matter accumulation, the crude protein yield and the amount of nitrogen accumulation increased with the N application. However, N dry matter production efficiency (NDMPE), dry matter production efficiency (DMPE), crude protein production efficiency (CPPE), N agronomic efficiency (NAE) and nitrogen apparent recovery ratio(NARR) decreased gradually with the increasing fertilizer application. When the fertilizer was applied at a rate of 350 kg/hm2-1050 kg/hm2, NARK was 23.16%-40.61% and N recovery efficiency (NRE) was 15.02%-18.32%. Test 3:Oblique cutting and 15cm stubble have highest fresh yield.