The effect ofAphelenchoides besseyi on 27 cultivars of rice （23japonica and 4 indica） was assessed in the field for two seasons during 2010 and 2011. The vigorous pathogenic nematodes culturing on Botrytis cinerea w...The effect ofAphelenchoides besseyi on 27 cultivars of rice （23japonica and 4 indica） was assessed in the field for two seasons during 2010 and 2011. The vigorous pathogenic nematodes culturing on Botrytis cinerea were used for this experiment. Inoculation was carried out at the tilling stage; the growth parameters and nematode population were recorded at the end of growth of rice plants. The results showed that the cultivars differed in their response to infection. Most of cultivars were lack of the characteristic symptom of white tip, which was seen less frequently than the other two symptoms, namely small grains and erect panicles; moreover, the expression of symptoms was probably hereditary. The infection lowered the values of all the measured biological parameters, namely length of the stem and of the panicle, the number of filled grains per panicle, and 100-grain weight, in all the cultivars. The final nematode population indicated that the threshold of economic damage had also been exceeded in 10 cultivars, and none of them was immune. Three japonica cultivars proved most vulnerable whereas Tetep, an indica type, showed a level of resistance potentially useful in controlling A. besseyi.展开更多
The paper was to understand the major factors causing outbreak of sugarcane pokahh boeng and the losses of yield and sugar content.The occurrence dynamics and influencing factors of pokahh boeng were analyzed.Under na...The paper was to understand the major factors causing outbreak of sugarcane pokahh boeng and the losses of yield and sugar content.The occurrence dynamics and influencing factors of pokahh boeng were analyzed.Under natural field condition,the diseased plant rate of main cultivated varieties was investigated in the damaged area and undamaged area established in the same field,and sugarcane yield and sugar content were measured and their losses were calculated at harvest period.The results showed that the prevalence of pokkah boeng mainly attributed to cultivation of susceptible varieties,high temperature and high humidity climate,accumulation of the pathogen and improper cultivation and management measures.Survey data showed the diseased plant rates were 63.3%-95%,with an average of 81.1%; the yield loss rates were 30.2%-48.5%,with an average of 38.42%; the sugar content were reduced by 2.63%-5.21%,with an average of3.61%; the sugarcane juice brix were dropped by 2.4-4.69 ° BX,3.61° BX on average; the gravity purities of sugarcane juice were decreased by 1.99%-8.14%,4.83% on average; the reducing sugars of sugarcane juice were increased by 0.05%-0.6%,0.16% on average.It is confirmed that the occurrence and damage of sugarcane pokkah boeng is severe at present stage,leading to huge loss of sugarcane yields and sugar content.Sugarcane pokkah boeng has become one of the main barriers of sugarcane production,and scientific and effective prevention and control of sugarcane pokkah boeng is very important for sustainable development of sugar industry.展开更多
基金supported by the Jiangsu Agriculture Science and Technology Innovation Project,China(CX(10)206)
文摘The effect ofAphelenchoides besseyi on 27 cultivars of rice （23japonica and 4 indica） was assessed in the field for two seasons during 2010 and 2011. The vigorous pathogenic nematodes culturing on Botrytis cinerea were used for this experiment. Inoculation was carried out at the tilling stage; the growth parameters and nematode population were recorded at the end of growth of rice plants. The results showed that the cultivars differed in their response to infection. Most of cultivars were lack of the characteristic symptom of white tip, which was seen less frequently than the other two symptoms, namely small grains and erect panicles; moreover, the expression of symptoms was probably hereditary. The infection lowered the values of all the measured biological parameters, namely length of the stem and of the panicle, the number of filled grains per panicle, and 100-grain weight, in all the cultivars. The final nematode population indicated that the threshold of economic damage had also been exceeded in 10 cultivars, and none of them was immune. Three japonica cultivars proved most vulnerable whereas Tetep, an indica type, showed a level of resistance potentially useful in controlling A. besseyi.
基金Supported by Special Fund for China Agricultural Industry Research System(CARS-170303)Special Fund for Agricultural Industry Research System of Yunnan Province(YNGZTX-4-92)
文摘The paper was to understand the major factors causing outbreak of sugarcane pokahh boeng and the losses of yield and sugar content.The occurrence dynamics and influencing factors of pokahh boeng were analyzed.Under natural field condition,the diseased plant rate of main cultivated varieties was investigated in the damaged area and undamaged area established in the same field,and sugarcane yield and sugar content were measured and their losses were calculated at harvest period.The results showed that the prevalence of pokkah boeng mainly attributed to cultivation of susceptible varieties,high temperature and high humidity climate,accumulation of the pathogen and improper cultivation and management measures.Survey data showed the diseased plant rates were 63.3%-95%,with an average of 81.1%; the yield loss rates were 30.2%-48.5%,with an average of 38.42%; the sugar content were reduced by 2.63%-5.21%,with an average of3.61%; the sugarcane juice brix were dropped by 2.4-4.69 ° BX,3.61° BX on average; the gravity purities of sugarcane juice were decreased by 1.99%-8.14%,4.83% on average; the reducing sugars of sugarcane juice were increased by 0.05%-0.6%,0.16% on average.It is confirmed that the occurrence and damage of sugarcane pokkah boeng is severe at present stage,leading to huge loss of sugarcane yields and sugar content.Sugarcane pokkah boeng has become one of the main barriers of sugarcane production,and scientific and effective prevention and control of sugarcane pokkah boeng is very important for sustainable development of sugar industry.
