The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bi...The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of the wilt disease were studied. The species was identified as Nectria ditissima Tul. at sexual phase, and as Fusarium semitectum Berk. & Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA+10% decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃, a great amount of macroconidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only produced under natural condition. The preference temperature for mycelia growth was between 25～28℃, and the optimum pH values was at 6～7. The optimum temperature for conidia and ascospores germination was between 25～28℃, and the optimum pH values was at 6～7. The high relative humidity (RH 96.1%～100%) was necessary for the germination of conidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil, and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurred from the last ten days of February or the first days of March. The peak infection occurred from the first ten days of March to the second ten days of April during early summer rains. The infection ceased from the second ten days or the last ten days of May. The freeze injury was possibly important factor to induce infection of the wilt disease.展开更多
Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla speci...Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla species have been tested as biological control agents on other crops, and have shown great potential in reducing the effects of pests. The effectiveness of Oecophylla as a biocontrol agent of fruit flies was compared with insecticide, Cypermethrin ＋ Dimethoate （Cydim super~） at Forest and Horticultural Crops Research Centre, Kade, in the Eastern Region of Ghana. The results have shown that trees colonized by Oecophylla had between 6%-10% fly infestation and Cypermethrin ＋ Dimethoate （1614 mg a.i. mL~ tree＂1） recorded 3.0% infestation. Cypermethrin ＋ Dimethoate treatment recorded 3.50 ~ 0.87 dropped fruits, and Oecophylla colonized-trees recorded 15 to 19.20 -4- 3.61. Oecophylla colonized-trees recorded yield values from 12.90 to 15.20 tons ha-~ whilst Cypermethrin ＋ Dimethoate treatment recorded 27.90 tons hat fruit yield. Total number of fly landings in the presence of Oecophylla （72.00） was significantly lower than the absence of Oecophylla （114.20）. Set-up with no Oecophylla recorded the highest infestation index （71.17） while the presence recorded 45.83. These results suggest that Oecophylla longinoda can be used as a biocontrol agent for IPM programs in citrus orchards.展开更多
文摘The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of the wilt disease were studied. The species was identified as Nectria ditissima Tul. at sexual phase, and as Fusarium semitectum Berk. & Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA+10% decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃, a great amount of macroconidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only produced under natural condition. The preference temperature for mycelia growth was between 25～28℃, and the optimum pH values was at 6～7. The optimum temperature for conidia and ascospores germination was between 25～28℃, and the optimum pH values was at 6～7. The high relative humidity (RH 96.1%～100%) was necessary for the germination of conidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil, and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurred from the last ten days of February or the first days of March. The peak infection occurred from the first ten days of March to the second ten days of April during early summer rains. The infection ceased from the second ten days or the last ten days of May. The freeze injury was possibly important factor to induce infection of the wilt disease.
文摘Fruit flies are causing extensive socio-economic losses in citrus orchards in Ghana. The flies as quarantine pests have detrimental effects on the export market due to international trade regulations. Oecophylla species have been tested as biological control agents on other crops, and have shown great potential in reducing the effects of pests. The effectiveness of Oecophylla as a biocontrol agent of fruit flies was compared with insecticide, Cypermethrin ＋ Dimethoate （Cydim super~） at Forest and Horticultural Crops Research Centre, Kade, in the Eastern Region of Ghana. The results have shown that trees colonized by Oecophylla had between 6%-10% fly infestation and Cypermethrin ＋ Dimethoate （1614 mg a.i. mL~ tree＂1） recorded 3.0% infestation. Cypermethrin ＋ Dimethoate treatment recorded 3.50 ~ 0.87 dropped fruits, and Oecophylla colonized-trees recorded 15 to 19.20 -4- 3.61. Oecophylla colonized-trees recorded yield values from 12.90 to 15.20 tons ha-~ whilst Cypermethrin ＋ Dimethoate treatment recorded 27.90 tons hat fruit yield. Total number of fly landings in the presence of Oecophylla （72.00） was significantly lower than the absence of Oecophylla （114.20）. Set-up with no Oecophylla recorded the highest infestation index （71.17） while the presence recorded 45.83. These results suggest that Oecophylla longinoda can be used as a biocontrol agent for IPM programs in citrus orchards.
