There are many types of foliar fertilizers. According to their effects and functions, foliar fertilizers can be summarized into four categories: nutritional, regulatory, biological and compound.

Under normal circumstances, after applying nitrogen, phosphorus and potassium fertilizers, they are often affected by factors such as soil acidity, soil moisture content and soil microorganisms, and are fixed and leached, which reduces the fertilizer efficiency. Foliar fertilizer can avoid this phenomenon and improve fertilizer efficiency. Foliar fertilizer is sprayed directly on the leaves without contacting the soil, avoiding adverse factors such as soil adsorption and leaching, so the utilization rate is high and the total amount of fertilizer can be reduced.

Nutritional status of the plant itself
Nutrient-deficient plants have a strong ability to absorb nutrients. If the plant grows normally and the nutrient supply is sufficient, it will absorb less after spraying foliar fertilizer; otherwise, it will absorb more.

The usage and dosage of Indole-3-butyric acid mainly depends on its purpose and the type of target plant. The following are several specific usage and dosage of Indole-3-butyric acid in promoting plant rooting: