Comparative Study On Harmfulness Of The Investigation And Control Methods Of Moss For Rice Field In Dalian

China is a big country of rice production and consumption in the world.Rice harvest plays an important role in China's grain price.Rice is the second largest grain crop after maize in Liaoning Province.However,as a production system,rice cultivation has always been at risk.Pests pose a threat to rice yield,such as Gramineae weed Sponge,but little research has been done on Sponge.The problem of moss has been becoming important disaster to the paddy fields in the north of China.The main hazards for moss is cutting down the water temperature,effecting on the growth and tillering for the rice,decreased rice yield.The water temperature was down to 2.8?,the water p H was rising up to 1.07,rice height decreased by 6.8cm and the reduction of yield reached 6.87% compared with the moss free plot,if the fraction of coverage is about 90%.The rice field would be affected seriously.At present,physical and chemical means were used for controlling,the result is not satisfactory or produce secondary pollution.Algicidal bacteria are paid more attention to control the moss in the world.The sample was taken from the rhizosphere in the scientific research base of rice,belonging baoning village,qingdui town in zhuanghe and isolated algicidal bacteria from the sample.Nine strains algicidal bacteria were isolated,serial passage five times for the stability test.And two strains were gained,they were labled A3 and A8.The gram reaction was made.Their physiological and biochemical properties indicated that A1 was characterized to be Micrococcus,A3 was Serratia,A8 was Acetobacter.The experimental result indicated that,A3 and A8 had an effect on cotrolling,the cotrolling effect of bacteria strains A3 was better than bacteria strains of A8.The bacteria strains A3 has a better cotrolling effects on the moss when the consentraion of 1.28×108 cfu·ml-1,the removal of moss was 65.85% after the fourth day.Applying different control methods to the field experiment,it was found that the beneficial microbial treatment with A3 strain had the best control effect on moss.It could obviously reduce the p H value of water body,increase the water temperature,plant height,tiller number and Yield Related Indexes of paddy field,and increase the yield by 6.46% compared with CK.