嘉寶果(Myrciaria cauliflora Berg.)在夏季環境下,新梢常有日燒、萎凋的情形發生,影響其生長與觀賞品質。本研究採用4種光線處理,分別為不遮光、遮光率30%之白色遮光網遮光(30% WN)、遮光率50%之黑色遮光網遮光(50% BN)及遮光率70%之黑色遮光網遮光(70% BN)處理,試驗結果以50% BN及70% BN遮光處理可有效降低嘉寶果夏季新梢日燒發生率。遮光處理具有增進嘉寶果株高及株寬的效果,且葉面積、比葉面積、葉綠素計讀値與葉綠素含量均高於未遮光的植株,顯示在短期遮光下,具有一定之蔭葉化能力。植株生物量以30% WN最高,50% BN次之,均大於不遮光栽培,而70% BN低光環境造成光合作用低落且光合產物生成少,生物量最低,植株明顯徒長且生長勢較差。為降低嘉寶果日燒問題及維持營養生長,夏季時可利用30%~50%遮光栽培,以提升觀賞品質。
The shoot sunburn and wilting often happen in summer and reduce the growth and ornamental quality of jaboticaba. The effects of different shading including control, white net with 30% shading (30% WN), black net with 50% shading (50% BN), and black net with 70% shading (70% BN) were evaluated. The 50% BN and 70% BN shading both lowered the shoot sunburn ratio of jaboticaba effectively in summer. Three shading treatments promoted the plant height and width. The leaf area, specific leaf area, chlorophyll meter reading, and chlorophyll contents of shading plants were higher than control. The results indicated that jaboticaba had acclimated to the short duration of shading. The biomass of jaboticaba with 30% WN shading was highest of all treatments, and that of 70%BN shading was lowest. Because the lower light intensity, photosynthesis of jaboticaba with 70%BN shading was lower, and plants growed more slowly. A cultural practice using 30~50% shading in summer to improve the vegetative growth and ornamental quality of jaboticaba was suggested in this research.