EFFECTS OF NPK RATES ON GROWTH AND SOME PHYSIOLOGICAL INDICES OF MINIATURE DENDROBIUM ORCHID (Dendrobium sp.)

Abstract

Nutrient has an important influence on physiology and biochemistry of plants. This work aims to study on influences of NPK rates on some biochemical and flowering indices of miniature Dendrobium (Dendrobium sp.) In this study, four NPK rates were applied by foliar spraying on Dendrobium plants, including CT1 (10:30:10), CT2 (10:10:30), CT3 (6:30:30), CT4 (10:30:30). The results showed that all four NPK rates increased significantly both catalase and peroxidase, two of enzymes breaking down hydrogen peroxide in plants. Flowering rate was enhanced and flower bud initiation was earlier in plants treated with NPK. The results revealed that application of NPK increased the spike length, number of florets per spike, floret width of  miniature Dendrobium. In particular, 100% miniature Dendrobium were flowering when treated with NPK=6:30:30. The spike length, number of florets per spike, floret width were strongest enhanced when plants treated with both NPK rates (6:30:30 and 10:30:30). These study results suggested that both NPK=6:30:30 and 10:30:30 could be used in producing miniature Dendrobium orchids.