Plant Growth Regulators (PGRs) are organic substance that can modify the growth of orchids. It can be synthesized by the orchids themselves or by human.
Auxins such as NAA (alpha napthaleneacetic acid) and IBA (indole-3-butyric acid). They are produced by the tip of orchids. They improve cell growth and elongation. Root formations are also guided by them.
Cytokinins such as BA (6-benzyl adenine or 6 benzyl aminopurine) and CPPU. When you apply this plant hormones with auxins, the new offshoots will appear. It plays a crucial role in many aspects of plant growth and improvement, including embryogenesis, maintenance of root and shoot meristems, and vascular development. The ratio between Auxin and Cytokinin is important.
Gibberellins (GA) such as GA3. The elongation of stem segment is increased by using this hormone. When you apply this chemical in high temperature environment, the orchid sugar (Sucrose, Glucose and Fructose) level will increase due to the increasing of the sucrose synthase.
Brassinosteroids. They are the only steroid plant hormones. They stop a falling of leaves and root growth. They play important roles in plant growth and development, regulating diverse processes such as cell elongation, cell division, photomorphogenesis, xylem differentiation, and reproduction as well as both abiotic and biotic stress responses.
Thiourea or Thiocarbamide is a chemical that can modify orchid growth and flowering. It develops an efficient sugar using process, respiratory system, and absorption in roots. It also plays a significantly increasing the net photosynthetic rates and the concentrations of total chlorophyll and starch in the leaves.
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