Effects of plant ages and fertilizer applications on growth and plant nutrition in Vanda ‘Wirat x Gordon’

Abstract

Thailand is the world's top exporter of orchids. According to good quality production, fertilization is one of the most important factors affecting plant growth and flower quality. Plant age related to fertilizer application for promote growth and development of orchid, however the research in this topic is rarely reported. Therefore, this experiment was aimed to study the effects of plant ages and fertilizer applications on growth and plant nutrition of Vanda ‘Wirat x Gordon’. The experimental design was factorial in a completely randomized design with 3x4 treatments. Plants were supplied with 2 factors: 1) plant age: 1, 2, and 3 years old plants and 2) fertilizer applications: 1) not receiving fertilizer (control), 2) 21-21-21 formula, 3) 13-27-27-27 formula and 4) 21-21-21 formula for 3 times, then 13-27-27 formula for 2 times. The fertilization method will provide fertilizer once a week at its concentration rate of 60 g/20 L. The plants will be grown in a greenhouse with 50 % shade, an average temperature of 27°C, an average relative humidity of 80%, and a light intensity of 350 µmol /m²/s. The results found that 3 years old Vanda had a higher growth and nutrient concentration than 1 and 2 years old Vanda. Plants received 21-21-21 fertilizer alternating with 13-27-27 resulted in better growth increment than other methods. The interaction between plant age and fertilizer rates showed that 3 years old Vanda supplied with fertilizer had the highest growth increment in plant height, leaf greenness, and concentration of phosphorus and potassium compared to the other methods.