溫州蜜柑（Citrus unshiu）之鉀素營養狀況調查初報

A Preliminary Investigation on the Status of Potassium Nutrition in Satsuma (Citrus unshiu)

民國六十六年間對本省溫州蜜柑之鉀素營養狀況作初步調查研究。先後自羅東三星鄉大穩村及苗栗三義鄉聖王坪兩溫州蜜柑園採取果實、葉片及土壤進行分析研究；其中對果實之外觀，果汁成分，葉片中之N、P、K、Ca、Mg含量，土壤中之P、K、Ca、Mg及若干土壤特性等，均會逐項分析鑑定，以供該二果園鉀素營養狀況研判之參考。綜合各項資料顯示：葉片中之鉀素含量較諸Embleton及Jones等人之研究所定標準為高，而其果實品質亦反映由於鉀素含量高而促使品質低下，此等情形或可歸咎於鉀素營養失當所致。本省溫州蜜柑看重早熟及適度之果實大小，以應加工製罐之需，此二條件均可由適當之鉀素營養狀況且促成。本省柑桔缺明確而適度之礦物營養狀況之研究，對果產之量、質之提高及其標準化恐難達成。

A preliminary investigation on the status of potassium nutrition of satsuma in Taiwan was conducted in 1977. Samples of fruits, leaves and soil were collected in citrus groves located in Shan-sin and Shan-yi respectively. The external and internal qualities of fruits, content of N, P, K, Ca and Mg in leave samples as well as soil characteristics and its p, K, Ca and Mg content were examined and determined for the judgement on potassium nutrition status. The overall results revealed that potassium content in leaves of both groves were higher than the criterion correlated by Embleton et a2,7) and the fruit had reflected inferior quality which may be attributed to unsuitable potassium nutrition. In Taiwan, early fruit maturity and moderate fruit size are desired for the purpose of processing and canning. It is acknowledged that these conditions can be worked out by proper adjustement of status of potassium nutrition. Since there is lack of thorough study on mineral nutrition of citrus in this Island, to raise the output and quality as well as standardization of products in citrus industry may scarcely be obtained.