柑橘營養之診斷與現況

Abstract

葉片營養診斷為多年生作物肥培管理之較佳指標。經過長期的試驗，本省柑橘果園之葉片營養診斷規範業已建立。葉片之取樣時期以8~9月間，取樣部位以當年生春梢無結果枝第3或4葉為準，並訂各種要素之適宜濃度範圍如下；依據上述基準本省柑橘果園之營養問題為氮偏高，鉀、鎂、鋅、硼偏低及部分果園銅過高。此種結果係民國71~72年160點及民國76年100點果園調查所得，前後調查結果相當一致。過多的氮肥使果實品質低下（果皮增厚，糖度降低）產量不但未增，反有降低趨勢；鉀肥的不足使果實品質降低（果小，糖、酸度降低）；鎂的不足使落葉增加而終影響品質和產量；硼的不足固影響果實品質，施用的不當亦易導致過多之傷害。 目前臺灣省農業試驗所將成立『土壤及植物體分析診斷中心』，將充實化學分析設備及設計適合本省使用之電腦營養診斷程式以提高診斷效率，並配合各區農業改良場及農會推廣人員之合作，加強有關服務及研究工作。 The bases of establishing optimum nutrient criteria of citrus leaves for the dignostic purpose in Taiwan have been reviewed. According to this criteria, the nutritional problems are high in nitrogen and low in potassium, magnesium, zinc and boron. Occasinally the content of copper is high, which might be related to the frequent foliar application of bordeaux mixture. The diagnostic services on citrus groves will be expanded by strengthening the facilities of chemical analysis and designing of computerized diagnostic programs at Taiwan Agricultural Research Institute, and collaborating with the extension works at District Agricultural Improvent Stations and Farmer’s Associations.