There are several known growth regulators. Some of them like auxins, cytokinins are growth promoting while others like abscissic acid, ethylene are growth inhibitors. Most of the growth regulators are synthesized by plants while a few are synthetic in nature.
The ratio of carbohydrates and nitrogenous compounds governs the pattern of growth. Presence of more carbohydrates favours good vegetative growth, flowering and fruiting. Presence of more nitrogenous compounds results in poor vegetative growth, flowering and fruiting.
All metabolic activities and growth are under genetic control.