S-abscisic acid has physiological effects such as causing bud dormancy, leaf shedding and inhibiting cell growth, and is also known as "dormant hormone".
It was discovered around 1960 and was mistakenly named because it was related to the falling of plant leaves. However, it is now known that the falling of plant leaves and fruits is caused by ethylene.

Trinexapac-ethyl belongs to the cyclohexanedione plant growth regulator, a gibberellins biosynthesis inhibitor, which controls the vigorous growth of plants by reducing the content of gibberellins. Trinexapac-ethyl can be quickly absorbed and conducted by plant stems and leaves, and plays an anti-lodging role by reducing plant height, increasing stem strength, promoting the increase of secondary roots, and developing a well-developed root system.

Paclobutrazol is an agricultural agent that can weaken the top growth advantage of plants. It can be absorbed by crop roots and leaves, regulate plant nutrient distribution, slow down growth rate, inhibit top growth and stem elongation, and shorten internode distance. At the same time, it promotes flower bud differentiation, increases the number of flower buds, increases the fruit setting rate, accelerates cell division

The mixing of plant growth regulators and fungicides depends on the mechanism of action of the agents, systemic conductivity, complementarity of the objects of control, and whether antagonism will occur after mixing. In some cases, such as to achieve the purpose of disease prevention or enhance plant disease resistance, promote plant growth or cultivate strong seedlings