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        검색결과 3

        2.
        2008.10 구독 인증기관·개인회원 무료
        Dongbu HiTek had a focal group depth interview with pesticide sales dealers and farmers in 2007. With results, dealers assessed a white fly as a most difficult pest in up-land crop cultivation, and answered the increase and change of pests and pathogen from climate change as a most concerned event. Farmers pointed that important jobs in vegetable cultivation were the control of pest and pathogen (34%) and the prevention of pest and pathogen (24%). And difficult works was the control of pest and pathogen (24%), and the climate change (18%). When choosing the insecticide, the long lasting activity (44%) and the completeness of control (34%) were the important factors. Among customers’ claims related with white fly, claims on insufficient efficacy was dominant and occupied 86% in spite of efforts of producers, and it reflected that commercial agrochemicals did not meet the expectation level of the farmers. Common agrochemicals for the control of white fly are Neo-Nicotinoids in Korea today and CGAR of it is about 13% average increased per year from 2003. As Bio Type Q showed higher resistant level to the Neo Nicotinoids than other Bio type (Nauen et al. 2002), Bio Type Q would spread easily and counter-plan is needed.. Market size of agrochemical for white fly is assumed to be about 9.6 million US dollars. The market size is smaller than that of aphids or lepidopterous pests, but the market would increase because of suffering and failure in control due to resistance and resurgence problems. As the increase of vegetable consuming, host crop for the white fly is also increasing. As green house cultivation area of host vegetable increases, natural enemies to foreign invading pest like sweet potato white fly are limited. Also it is important that that management of pest and pathogen in green house environment. It is essential to build pest management model and to develop and commercialize agrochemicals according to the critical customer (farmer) requirement.
        3.
        2008.05 구독 인증기관·개인회원 무료
        Among the cultured products of Beauveria bassiana SFB-205 (KCCM 10892P), the supernatant showed the highest insecticidal activity against 2nd instars of Aphis gossypii (Aphididae) nymphs under glasshouse condition. The enzymes in the supernatant were confirmed as active materials, and the chitinase was finally selected as a QC factor for commercial production. However, the chitinase activity in the supernatant decreased by 11-folds due to the thermal stress at 50℃ for 2 h. To obtain thermal stability, the chitinase in the supernatant was adsorbed to a precipitable material and the pellet was freeze-dried (PCT/KR2007/005886). The adsorbent-A showed about 92.7% of harvesting efficiency which was higher than the other candidates. The chitinase activity of the freeze-dried powder was kept up about 82.0% of initial activity for the same thermal stress. Subsequently, an optimal formulation recipe was established to maximize long-term storage stability and efficacy. SFB-205 oil-based formulation was stable up to 18 months at room temperature. It showed 96.1% efficacy against 2nd instars of A. gossypii nymphs at 1 day after the treatment in the glasshouse. This novel approach can be a promising method to develop competitive biopesticies in the entomopathogenic fungi, even though it needs to be intensively studied.