施氮對芋植株生長及乾物生產分配之影響

Effects of N Fertilization on Growth and Biomass Production of Taro Crop

蔡永暭(Yuong-How Tsai)

《高雄區農業改良場研究彙報》 11卷2期 (2000/06) Pp. 22-36

https://doi.org/10.6958/RBKDAIS.200006.0022

摘要

芋是熱帶及亞熱帶地區重要的球莖作物。為了促使地下球莖肥大，芋需要吸收充足的氮素，以累積大量的乾物質，並順利轉移至地下部。本研究目的，即是探討氮素與芋植株生長及乾物生產分配之關係。試驗結果顯示，株高、葉片面積、乾物重、及球莖產量等性狀與氮肥用量呈極顯著之正相關，且差異以倍數計。無氮區植株矮小黃化，提早成熟，球莖公頃產量，水芋4～6公噸，旱芋6～14公噸。施用氮素後，株高及葉片面積均隨施氮量增加而增加，球莖公頃產量，水芋31～34公噸，旱芋21～23公噸，水芋平均增產452～493%，旱芋60～138%。過量施用氮素，乾物質大部分累積於地上部莖葉，不易轉移至地下球莖，造成乾物分配率及收獲指數降低。氮素公頃推荐量，新作田水芋為640公斤，旱芋為340公斤，而連作田施用量高於新作田。若採用促成栽培，實施水分管理，並配合生育期 調整施肥技術，則芋施肥量可望再降低。

關鍵字

芋 ； 氮素 ； 生育性狀 ； 乾物生產量 ； 乾物分配率 ； 收穫指數 ； 塊莖產量

並列摘要

Taro (Colocasia esculenta (L.) Schott) is an important root crop in the tropical and sub-tropical area. Taro can be distinguished as wetland and upland crop according to water management. Under optimum conditions, taro develops a large leaf area and accumulates substantial amounts of dry matter in the corms. In order to support this high biomass production, providing enough N is necessary. The purpose of this study is to understand the effects of N rates on growth and biomass production of taro crop and to recommend the appropriate N fertilizer rate for taro production. Field trials showed that plant height, leaf area, biomass production, and corm yield are the most important growth characters affected by N application. Without N application, corm yield reduce to 4~6 t/ha for wetland taro, and 6~14t/ha for upland taro, and also reduce plant size and prompt maturity by 1~2 months. After applying appropriate N fertilizer, plant size is getting bigger, while the corm yield reach to 31~34t/ha and 21~23t/ha for wetland and upland taro, and in this case, corm yield increase 452~493% and 60~138%, respectively. Excessive N fertilization also favors top growth, but reduces the proportion of dry matter allocated to the corms. And therefore cause both partition rate and harvest index for corm lower. For 1st-year taro, the recommendation of N are 640 kg/ha and 340kg/ha respectively for wetland and upland taro, however, the amount of N recommendation for continuous taro are much higher. Nitrogen rate can be reduced if adjusting fertilization technique and water management according to the growth stage of taro.

並列關鍵字

Taro (Colocasia esculenta (L.) Schott) ； N application ； Growth character ； Biomass production ； partition ratio ； harvest index ； Corm yield