Analysis Of Suitability Of Pennisetum Clandestinum In Beijing

Pennisetum clandestinum is an ornamental grass with ornamental value and wide applying prospect. Invased into Beijiing is analysed through climate of native and introducing area, seed trait, competition ability, environment stress, effect on disease and insect, and history of invasion in other countries. The results indicate that:(1)Temperature and rainfull in Beijing can satisfy with the growth and development of P. clandestinum.(2)Seeds of P. clandestinum can germinate from 15℃to 40℃. The optimal germination temperature is 26℃. The better germination rate occurrs in 15mm to 20mm depth under surface of soil with optimal depth of 13mm. The dormant period lasts about five months, the dormant period can be shortened to two months if the seeds stored in soil. Germination rate descends to 32.5 % from 92% rapidly afrer Accelerated Aging(AA) Test. germination rate descends to 26.0% from 51.0% After Cold Test.(3)There is no siginificant difference of biomass and economic yield of maize, and soybean with the growth densities of P. clandestinum 1,1.6,2.5,3.3,4.2 indvidual plant/M~2, respectively. It certifies that P. clandestinum has no advantage over main plants in Beijing.(4) P. clandestinum is not so sensitve to water stress compared with salt stress. Proline and MDA content increase and Chlorophy content declines in P. clandestinum when water content in soil is 60% of water content in the field, whereas there is no siginificant difference of height and tiller of P. clandestinum compared with control. height and tiller of P. clandestinum are lower than control while water content in soil is 40% of water content in field. Morphological index of P. clandestinum is lower than control when salt concentration is from 50 mmol/L to 200mmol/L.(5)Few insect species, such as locust, cricket and mantis can be found during P. clandestinum growth period. It infers that natural enemies have weak control effect against P. clandestinum.(6)P. clandestinum is an ornamental plant in others countries, whereas it is a kind of invasive plant in few country such as in New Zealand.In conclusion, P. clandestinum has a high suitability in Beijing as an ornamental grass, but it should be prevented to be the possibility of being a invasion species if escaped.