檸檬葉片營養調查與氮營養診斷

Leaf Nutritional Survey and Nitrogen Diagnosis of Lemon （cv. Eureka）

謝鈞翔(Jun-Xiang Xie)

指導教授 ： 王鐘和

國立屏東科技大學/農學院/農園生產系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00186

摘要

檸檬為台灣重要果樹作物，由於檸檬用途較廣，市場需求量較大，經濟價值高，在我國目前尚無檸檬合理土壤肥培管理之相關研究成果，為促進檸檬產業的發展，了解植體營養狀況藉以推薦合理施肥相當重要。本試驗就屏東縣九如鄉之檸檬產區，進行營養狀況調查，並以葉綠素計（chlorophyll meter）和影像分析（power image analysis, PIA）之應用，探討作為葉片氮營養診斷工具之可能性。
試驗結果顯示，檸檬園土壤肥力隨作物生育期、施肥等因素變化，葉片氮、磷、鉀濃度在施肥時期增加，於三到九月份開花結果期逐漸減少，九月份過後濃度下降，顯示樹體養分經盛產期大量消耗，且因該時期未施用肥料，使樹體養分減少。檸檬葉片營養濃度與國外檸檬葉片營養診斷用之各要素濃度適宜值相比，氮、磷、鉀、鎂、硼濃度均達適宜濃度範圍之內，故國外之適宜值可作為參考，而鈣、鐵、錳、銅、鋅濃度則不適用。葉片鉀濃度與鈣、鎂濃度呈顯著負相關。因五至六月份為開花期與結果期並存時期，於採收春花果後進行診斷，並於盛產期之果實膨大期作施肥處理較為適宜，此時春梢葉葉齡約為五個月大之成熟葉，推薦葉片營養診斷期為五至六月份。氮肥用量過多產量無明顯增加，而鉀肥的配合施用產量可達最高，氮、鉀肥同時施用過量，產量未明顯增
加。提高鉀肥用量可提高總可溶性固形物含量，降低可滴定酸含量，增加固酸比。
葉片氮濃度和檸檬產量兩者間具有顯著之二次相關，葉片氮濃度超過28.5 g kg-1（一月）、26.1 g kg-1（三月）、27.1 g kg-1 （五月）、20.7 g kg-1 （七月），產量不再隨氮濃度之增加而提高，此一臨界值可提供不同檸檬產期氮營養管理之參考。葉綠計測值（chlorophyll meter reading, CMR）和葉片氮含量兩者間具極顯著之正相關，和檸檬產量兩者間也有極顯著之二次相關，CMR值超過65.4（五月）、66.1（七月）時產量則下降。CMR值和影像分析值間呈極顯著之線性正相關，葉片氮濃度和影像分析值間有趨勢但無顯著相關，影像分析值與產量間呈顯著之二次相關，趨勢與葉片氮濃度和產量之相關性相同，顯示若經技術改良，可藉由影像分析偵測檸檬植株之氮營養狀況，作為氮營養管理依據之一。葉片鎂、鐵含量與CMR間無顯著相關。

關鍵字

檸檬 ； 營養診斷 ； 氮 ； 葉綠素計 ； 影像分析

並列摘要

Lemon is an important fruit crop in Taiwan. It has larger market demand for and high economic value. There is few research about soil and fertilizer management for lemon in Taiwan. Understanding of the nutritional status of fruit trees is very important to recommend rational fertilization, to promote the lemon industry. This study investigated the nutritional status, and the possibility of using chlorophyll meter and power image analysis (PIA) to diagnosis nitrogen nutrition at the lemon-production areas in Pingtung County.
The results showed that soil fertility is changing with crop growth, fertilizer application and other factors. Nitrogen, phosphorus and potassium concentrations of leaf increased after fertilizer application. It decreased gradually during flowering and fruiting period in March to September, the concentration of leaf dropped after September, a large amount of nutrients consumed by the fruit, because at this period no fertilizer was applied, so that
the nutrients concentration decreased. The concentrations of nitrogen, phosphorus, potassium, magnesium, boron of leaf were within the range of the appropriate concentration of nutrients diagnosis of lemon from foreign references. So it can be served as a diagnosis references, but calcium, iron, manganese, copper, zinc were beyond the range of appropriate values. There was a significantly negative linear correlation between potassium concentration of leaf with calcium or magnesium concentrations of leaf. Both of flowering and fruiting exist simultaneous in May to June, undertaking leaf diagnosing after first fruit harvested, it is appropriate to apply fertilizer at fruit rapid growth stage. The appropriate period of leaf nutrient diagnosis is from May to June, the leaf is 4-month-old spring flush leaf. Applied excessive amount of nitrogen did not increase yield, the combined application of potassium got the highest yield, both excessive applied of nitrogen and potassium fertilizer was no significantly positive effect of yield. Increased the amount of potassium fertilizer increased the total soluble solids and the sugar to acid ratio, and decreased titratable acid content.
There was a significantly quadratic correlation between N concentration of leaf and fruit yield. When nitrogen concentration were above 28.5 g kg-1（Jan.）, 26.1 g kg-1（Mar.）, 27.1 g kg-1 （May）, 20.7 g kg-1 （Jul.）, fruit yield decreased with the increased of nitrogen content, this critical value may serve as a reference for nitrogen nutrition management of lemon. There was a significantly positive linear correlation between chlorophyll meter reading (CMR) and N concentration of leaf. There was a significantly quadratic correlation between CMR and fruit yield, when CMR were above 65.4（May）, 66.1（Jul.）the yield decreased, and there had a significantly positive linear correlation between CMR and PIA. There was a significantly quadratic correlation between PIA and fruit yield, the relationship between PIA with fruit yield, N concentration of leaf or fruit yield were similar, so using PIA may be able to diagnose nitrogen nutrition status of lemon after technical improve, as one of the basis of nitrogen nutrition management. There were no significantly relation between magnesium or iron concentration of leaf and CMR.

並列關鍵字

Lemon ； Nutrition diagnosis ； Nitrogen ； Chlorophyll meter ； Power image analysis

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