甘藍、包心白菜和包心芥菜之偽萊蚜和桃蚜防治基準之訂定

Abstract

偽菜蚜，Hyadaphis erysimi（Kaltenbach )，和桃蚜，Myzus persicae（Sulzer ) ，均為十字花科蔬菜在晚秋至次年夏初之主要害蟲。在蔬菜生長初期被害，影響蔬菜之發育至鉅。對這些蚜蟲之防治，以殺蚜劑控制蚜蟲之族羣密度，設定蚜蟲之為害葉率多寡而釐定防治之基準。經由1984至1987分別在甘藍，包心白菜和包心芥菜試驗結果，則甘藍之蚜蟲為害葉率為≥30％或每3－4週施藥1次。包心白菜和芥菜為≥20％或2－3週施藥l次。醃漬用之包心芥菜為≥40％或每4週施藥1次。均可達防治之目的，且對產量和品質都無實質之影響。 Turnip aphid, Hyadaphis erysimi (Kaltenbach) and green peach aphid, Myzus persicae (Suizer) occurred seriously on cabbage, chinese cabbage and leaf mustard from late autumn to early summer of the next year. For control of these aphids, action thresholds were evaluated during 1984-87. Aphid densities were established by using insecticide to manipulate infestation levels. T he aphicide applied whenever the aphid-infested leaf reached≥30% on cabbage, and≥20% on chinese cabbage and leaf mustard, would not cause any yield reduction. Satisfactory results could also be obtained by the application of aphicide at the intervals of 4 weeks for cabbage as well as 3 weeks for chinese cabbage and leaf mustard during the the peak period of occurrence of both species of aphids.