Correlation studies on nutrient content of epiphytic orchids and associated substratum

The study was conducted to find out the chemical composition and correlation between nutrient content of epiphytic orchids and associated substratum in the subtropical belt of Sikkim. Seven species of epiphytic orchids viz., Dendrobium densiflorum, Dendrobium moschatutn, Dendrobium aphyllum, Dendrobium chrysotoxum Densiflorum, fimbriatum, Luisia filiformis, Vanda cristata and associated substratum were collected and analyzed for nutrient composition. The total nitrogen content of orchid species varied from 1.1 (Vanda cristata) to 2.8 gflcg dry weight (Dendrobium fimbriatum), the total potassium content varied from 5.7 (Vanda cristata) to 14.2 g/kg dry weight (Dendrobium aphyllum), the total calcium content varied from 21.0 (dendrobium chrysotoxum) to 36.6 g/kg dry weight (Luisia filiformis), the total magnesium content varied from 11.0 (Dendrobium chrysotoxum) to 30.0 g/kg dry weight (Vanda cristata) and the total sulphur content varied from 10.0 (Vanda cristata) to 23.0 g/kg dry weight (Dendrobium densiflorum). Linear regres-sion analysis indicated that the variation in N, P, K, Ca, Mg and S content of orchid species were significantly influenced by those of the associated substrata to the extetent of 83.74,75.01,96.58,86.39,81.06 and 63.39%, respectively.