Effects of Sphagnum Moss Water Content, Fertilizer Concentration, Vernalization and Floral Bud Development Temperature on the Growth and Flowering in Nobile Dendrobium

• Main Authors: Yi-Ting Yeh, 葉依婷
• Other Authors: Rong-Show Shen
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/79751868154371441763

碩士 === 國立嘉義大學 === 園藝學系研究所 === 101 === This study aimed to explore effects of sphagnum moss water content (SMWC), fertilizer concentration, vernalization and floral bud development temperature on growth and flowering of nobile Dendrobium. In SMWC treatment, Den. Lan Tarn Beauty and Den. Tian Mu Diamond were fertigated when SMWC decreased to 13%-15%, 18%-20% or 23%-25%. The new shoot sprouting and terminal leaf formation of Den. Lan Tarn Beauty and Den. Tian Mu Diamond were promoted at 13%-15% or 18%-20% SWC. It showed that lower SMWC were the reasonable fertigation frequency on sprouting and pseudobulb development. In addition, Peters 15N-5P2O5-15K2O and Peters 20N-20P2O5-20K2O were tested at various concentrations, a total of seven treatment, on two cultivars (Den. Hototogisu ‘Ballerina’ and Den. Lan Tarn Beauty). The results showed that optimal vegetative growth on current pseudobulb were 100 mg•L-1 nitrogen, 29.4-43 mg•L-1 phosphorus, and 83-166 mg•L-1 potassium for Den. Hototogisu ‘Ballerina’, and were 100 mg•L-1 nitrogen, 14.7-43 mg•L-1 phosphorus, and 83 mg•L-1 potassium for Den. Lan Tarn Beauty. According to the aforementioned results, 0.5 g•L-1 Peters 20N-20P2O5-20K2O was a recommended fertilizer source and concentration during pseudobulb growth stage. In water content of sphagnum moss combined fertilizer source with concentration experiment, using 13%-15% of SMWC with 0.67 g•L-1 Peters 15N-5P2O5-15K2O could enhance flower qualities of Den. Lucky Girl. Plants used 1.0 g•L-1 Peters 20N-20P2O5-20K2O as fertilizer could produced more flowers, but had smaller flower diameter and shorter flower longevity. Lower nutrient applied, Control and 0.33 g•L-1 Peters 15N-5P2O5-15K2O treatment, caused leaf yellowing of Den. Lucky Girl on flowering stage. Mature Den. Hototogisu ‘Ballerina’ and Den. Lan Tarn Beauty were cooled at 13 or 15℃with three vernalization durations (15, 30, or 45 days). After vernalization, plants had 66%-83% remaining leaf percentage. Remaining leaf decreased under longer vernalization duration. A cooling period of 45 days at 15℃ resulted in higher flowering plants percentage and flowering node percentage in Den. Hototogisu ‘Ballerina’ and Den. Lan Tarn Beauty. However, A 15-day vernalization was unfavorable for flower induction. Den. Hototogisu ‘Ballerina’ and Den. Lan Tarn Beauty had great flowering plants percentage after two-stage vernalization. The results showed that optimal two-stage vernalization for two Dendrobium cultivars were cooled at 13℃ for 30 days and then at 15℃ for 15 days subsequently, then the plants would take 83 days to flowering from the beginning of two-stage vernalization. Furthermore, temperature affected floral bud development after two-stage vernalization. Den. Lan Tarn Beauty had higher flowering node percentage and total flower number at 25/20℃. Although mature plants placed at 20/15℃ had lower flower number and smaller flower diameter than those in 25/20℃, it could prolong the time to flowering and flower longevity. Therefore, a lower temperature of 20/15℃ could be used in flowering regulation. Higher temperature of 30/25℃ or raised temperature gradationally could advance time to flowering, but flowering node percentage, total flower number and flower longevity decreased, reducing flower qualities of Den. Lan Tarn Beauty.