THE EFFECTS OF TIME OF CUTTINGS ON THE YIELD AND PYRETHRIN OF PYRETHRUM FLOWERS

Abstract

除蟲菊(Chrysanthemum cinerariaefolium. Bocc)屬菊科(Compositeae)，宿根草本植物，其所含Pyrethrin成分有驅蟲作用，可製成害蟲驅蟲劑，蚊香、農藥中殺蟲乳劑與粉劑等用途。據松田秀維（1939）研究Pyrethrin對動物毒性之反應，謂對冷血動物有毒，對溫血動物毒性甚弱，因在血液中吸收之際，為高溫加水分解，毒力減弱。池田長守（1950）研究除蟲菊含Pyrethrin量之分佈，謂以花含量最高，達1.19%，葉0.23%，莖0.12%，根0.1%，由資料可知藥用部份為花。又Gnadinger and Con (1930)及武居、今木等(1932)研究除蟲菊花採收期之報告，謂在滿開期 Pyrethrin含量最高，達1.15~1.43％。松田秀雄(1939)研究除蟲菊乾花收量每分地第1年及第2年各為100~200kg，第3年，52kg，第4年，37kg，第5年34kg，第6年29kg，由資料顯示前2年經濟價位較高。日本農林省所定除蟲菊花含Pyrethrin量標準為0.9%，超過此標準即有經濟價值。本省耕地面積有限，平地少，山地多，廣大的山坡地宜開發利用栽植本經濟作物，裨益農家經濟，爭取外匯。 本所過去向日本引進除蟲菊新品種，試栽成功，為本省新興作物之一，Pyrethrin含纖高，可抽取製成殺蟲劑，其優熱是不致如DDT噴灑後含有殘毒，貽害人畜。又除蟲菊採花費時費力，故本研究之目的一方面在探究除蟲菊花在本省栽培所含Pyrethrin量；另方面尋求採花之適當時期，以提高產量，作為今後農民栽培之參考。 For lifting the Pyrethrin content and flower production in Pyrethrum flowers, the suitable harvesting period was investigated. The experiment was held in Tahshue Mountain from Jan. 1972 to Dec. 1973. The variety of Japan type insect flower conagen 1 and three different harvest period were tested, The results obtained are as follows: 1. The plant height and tiller number were increase when plants grown. Owing to the different harvesting period, there were significant difference in flower number and flower diameter which affected the flower production (Table 1). 2. Flower harvested in full bloosom stage had the maximum two-year production as 135.8 g, however, there was only 48.9 g. harvested in emerge bloosom period (Table 2). 3. There were the highest dry flower weight, dry flower ratio, and weight of 100 flowers harvested in the full bloosom period (Table 3) and also got the highest Pyrethrin content in this stage (Table 4). Thus, the different picking period not only affected the Pyrethrin content but also affected the quantity of flower production