Flowering depends on the amount of carbohydrate and hormone in plants. The flowering of tropical orchids can be controlled by following methods.
Fertilizer, this is the most famous method in Thailand, we use 13-27-27 fertilizer grade for hybrids dendrobium and 10-15-17 fertilizer grade for Vanda. We use 1.5-2.0 times higher ratio than usual, 2-4 weeks. And reduce water 1 day before fertilizing. But do not continuously fertilizing more than 4 weeks.
Cutting the young inflorescence, this method is suitable for the rapid flowering orchid due to high nutrient storage at the pseudobulb. You have to check how many days that they will bloom again.
Slow cutting inflorescence, this method will slow a creating of new inflorescence due to the orchids still loss an energy to maintain the old one. When you want a new one, you just cut it.
Controlling the environment (light and temperature), when CAM orchids such as Vanda and Aranda receive light to the saturated point, they will bloom more than usual due to more photosynthesis reaction. And for Cattleya, when they receive too much humid, they will stop bloom. And For phalaenopsis, when the temperature is higher than 27 degree Celsius, they will stop bloom.
Cutting the root, this method must apply with the using of NAA hormone. It will induce a new root and create Cytokinin hormone which affects Vanda to have a new bud.
Dividing the front pseudobulb, when you separate the front pseudobulb from the main orchids, plant will have adequate food for a new inflorescence.
Decapitation/incision, this method wastes a labor work. There is a report that said when you cut the tip of front pseudobulb of dendrobium, it will form more than 1 inflorescence per pseudobulb.
REF: ว่าด้วย กล้วยไม้: ศาสตร์และศิลป์ เพื่อการพัฒนา
