溫度與無機養分對波斯頓腎蕨生長之影響

Effect of Temperature and Mineral Nutrition on Growth of Nephrolepis exaltata 'Rooseveltii'

波斯頓腎蕨幼苗於溫室及人工氣候室日／夜溫30/25°C、25/20°C、20/15°C栽植，研究不同溫度及無機養分對其生長及礦物成分之影響。植株於30/25°C生長快速，葉數增生最多但葉片不長；25/20°C下植株葉片最長最具欣賞價值。20/15°C下生長緩慢，且有葉片黃化及壞疽之寒害現象。鮮重、乾重和葉面積以每週施2次1/2 Johnson氏完全營養液最高。生長良好葉片組織含氮量應在1.7～2.5%間，含量再增加使葉色更濃綠但對產量並無助益；含磷量甚高，在0.5～0.7%，而含鉀量應在2.8～3.8%。不施肥或少施肥處理者含鎂量偏高，鎂與鉀在葉片組織具拮抗關係。

Effects of temperature and mineral nutrition on growth and mineral composition of Nephrolepis exaltata 'Rooseveltii' (Boston fern) in greenhouse and phytotron at different day / night temperature of 30/25°C, 25/20°C and 20/15°C were studied. Boston fern produced more frond numbers at 30/25°C but fronds grew longer at 25/20°C which had the best quality. Growth was considerably low and chilling injury was found in fronds which showed the chlorotic and necrotic tissues at 20/15°C. The greatest amount of growth in the ferns was produced by applicating a half-strength of Johnson's nutrient twice per week. Frond numbers increased as fertilization concentration and application times increased up to a full-strength dosage twice per week. Luxury fertilizer application made fronds darker green but produced compact ferns which had more frond numbers and shorter fronds. Tissue analysis indicated that nitrogen content in fronds of good quality plants was found at range of 1.7~2.5%; phosphorus content, 0.5~0.7%; potassium content, 2.8~3.8%; Antagonisms between potassium and magnesium were found in frond tissues composition.