2019 ASHS Annual Conference

Effects of volumetric water content on growth and photosynthesis of Platycerium wandae

Chun-An Liu* and Der-Ming Yeh

Department of Horticulture and Landscape Architecture, National Taiwan University

Staghorn ferns are high valued and have been used extensively in many areas for landscaping, with great potential for markets’ demands. However, staghorn ferns grow slowly because they thrive as epiphytes in the forest canopy with fluctuations of water availability in distinct wet and dry seasons. A better understanding of their water requirement would facilitate faster production. In this research, plants of Platycerium wandae Racif. with two sterile fronds were grown with a potting medium of 2 peat moss: 2 vermiculite: 1 perlite (by volume). Growth and photosynthesis were measured in plants under 30% volumetric water content (VWC), 70% VWC (moisture), 20% VWC (drought), and 20/70% (drought/moisture) VWC treatments for three months. Results show that plants under 20% VWC had the lowest dry weight, frond area, net photosynthetic rate, and stomatal conductance, but highest internal CO₂ concentration. Therefore, long-term drought stress led to slow growth through both stomatal and non-stomatal limitation. Plants under 30% VWC and 70% VWC did not differ in growth and photosynthesis. Plants under 20/70% VWC had the highest dry weight and net photosynthetic rate, and the largest frond area due to the appearance of rapidly bending sterile fronds. Chlorophyll fluorescence measurements, such as Fv/Fm, did not differ among the four VWC treatments.