氮及磷肥對兔眼藍莓光合作用、生長與開花之影響

Abstract

兔眼藍莓 (Vaccinium ashei Ait.) 為溫帶落葉果樹，低溫需求低、耐熱且對土壤適應力較強，有於台灣平地栽培之潛力。本研究以3年生盆植’Blueshower’兔眼藍莓為材料，探討氮、磷肥濃度對植株開花與生長之影響。處理為三個氮濃度(100、200、400mg/L)及二個磷濃度(200、400mg/L)之六種組合加上未施用氮磷之對照組共7種處理。於2012年11月9日開始每周處理一次肥料溶液。測量植株不同季節葉片之光合作用及SPAD值、施肥後之開花數、花芽數及每花芽產生花朵數，以及生長季中枝條總生長量。 秋冬季時，所有施用氮磷之處理植株葉片的淨光合作用速率彼此無差異且顯著高於未施用氮磷的控制組；夏季時所有處理植株之葉片淨光合作用速率彼此無差異且平均值略低於冬季施用氮磷處理之值。秋冬季施用氮磷之處理葉片葉綠素計讀值隨氮施用量增加而顯著上升、磷施用量不造成顯著差異且所有施用氮磷處理之值顯著高於控制組；夏季時施用氮磷之處理葉綠素計讀值與氮、磷之關係與秋冬季相同且平均值較秋冬季低；控制組之值較秋冬季高且與施用100 mgN/L之處理無顯著差異。代表在秋冬施用氮磷可顯著增加藍莓葉片之淨光合作用速率及葉綠素計讀值。植株之開花數隨氮之施用量增加而顯著增加，磷施用量未造成顯著差異，且所有施用氮磷之處理皆顯著高於控制組；花芽數及每花芽開放之花朵數不因氮磷施用量而有顯著差異，但氮磷之處理皆顯著高於控制組。植株總枝條生長量隨磷之施用量增加而顯著減少，與氮肥施用量無關，較低濃度之磷肥處理有較多之枝條生長量。

The rabbiteye blueberry (Vaccinium ashei) is a deciduous shrub with low chilling requirement, tolerance to high temperature and soil pH range, which has the potential for commercial cultivation in Taiwan’s lowland. We investigated the effect of application of N and P on the performance of vegetative and reproductive growth of rabbiteye blueberry in Taiwan’s lowland. Potted 3-year-old ‘Blueshower’ plants were fertigated weekly from 9 November 2012, with N at 100, 200, 400mg/L in combination with P at 200 or 400mg/L. Plants fertigated without N and P were served as the control. Leaf photosynthesis rate and SPAD-502 value were measured in March and October, 2013, considered as overwinter leaves and summer leaves, respectively. In overwinter leaves, plants fertigated with any N and P conc. had higher photosynthesis rate than the control but no significant difference was detected among fertigation treatments; leaf SPAD-502 value also significantly higher in plants fertigated with N and P than control, and the value increased with N conc. but was not influenced by P conc.. In summer leaves, leaf SPAD-502 value was also increased with N conc. but was not influenced by P conc. There was no significant difference of photosynthesis rate and SPAD-502 value between all treatments. Numbers of flowers and flowering buds were recorded from the beginning of treatment and both increased with increasing N conc. but was not influenced by P conc. Conc. of N, P only influenced numbers of flowers and flowering buds but did not affect timing of flowering. Cumulative shoot growth in 2013 decreased with increasing P conc. but was not influenced by N., and the control significantly lower than fertigated treatments.