Physiological Response of Dendrobium cv. Earsakul to Plant Growth Promoters and Growing Systems

Abstract

This chapter discusses the investigation on ‘Physiological Response of Dendrobium cv. Earsakul to Plant Growth Promoters and Growing Systems’ that was conducted at the College of Horticulture, Vellanikkara, Thrissur, Kerala, from April 2011 to March 2013. This experiment was carried out with an objective to study the response of Dendrobium cv. Earsakul to nutrients, plant-growth-promoting root endophyte, Piriformospora indica (PGPRE) and plant growth regulators under three microclimatic conditions. The experiment was laid in CRD with six treatments and four replications. The results revealed that maximum leaf area (29.99 cm2), relative growth rate (0.013 g g−1 day−1) and number of stomata (41.14) were observed in 6-month-old plants, whereas maximum dry matter production (20.92 g plant−1) and crop growth rate (0.148 g m−2 day−1) were observed in 3-year-old plants treated with T4. Higher levels of dry matter production (14.27 g plant−1), crop growth rate (0.131 g m−2 day−1), rate of photosynthesis (6.36 μmol CO2 m−2 s−1) and transpiration rate during day time (6.56 μmol m−2 s−1) were observed in 6-month-old plants treated with T3. Maximum rate of transpiration during nighttime was recorded in plants treated with T2 (0.26 μmol m−2 s−1). Among the systems of growing, rate of photosynthesis (6.86 μmol CO2 m−2 s−1), transpiration rate during night (0.32 μmol m−2 s−1) and transpiration rate during day (6.00 μmol m−2 s−1) were observed to be higher in 6-month-old plants grown under top-ventilated polyhouse system (S2). Maximum values were also observed for the remaining physiological parameters of plants grown in top-ventilated polyhouse. The association between plant growth promoters and systems of growing significantly influenced the physiological attributes of plants.