Salicylic acid plays multiple roles in agriculture, including being a plant growth regulator, an insecticide, and an antibiotic.
Salicylic acid, as a plant growth regulator, plays a significant role in promoting plant growth and increasing crop yields. It can enhance the synthesis of hormones within plants, accelerate their growth and differentiation, and also help plants adapt to environmental changes. Salicylic acid can also effectively inhibit the elongation of plant tips, making plants sturdier and reducing the occurrence of diseases and pests. Besides being a plant growth regulator, salicylic acid can also be used as an insecticide. In the agricultural field, common examples include acetylsalicylic acid and sodium salicylate. These chemicals can effectively kill pests and diseases that parasitize on plants, protecting the growth of crops. In the medical field, salicylic acid is also a common anti-infective drug. In the agricultural field, salicylic acid is used to prevent infectious diseases in animals. At the same time, salicylic acid can enhance the disease resistance and storage time of agricultural products.
Salicylic Acid (abbreviated as SA) is not a traditional pesticide (such as insecticide, fungicide, or herbicide) in agriculture. However, it plays an extremely important role in the plant defense mechanism and the regulation of stress resistance. In recent years, salicylic acid has been widely studied and applied in agriculture as a plant immune inducer or biological stimulant, and it has the following main functions:
1. Activation of plant systemic acquired resistance (SAR)
Salicylic acid is a naturally occurring signaling molecule in plants, which accumulates rapidly after pathogen infection.
It can activate systemic acquired resistance (SAR), causing the entire plant to develop broad-spectrum resistance against various pathogens (especially fungi, bacteria, and viruses).
2. Enhance the tolerance of plants to non-biological stress
Salicylic acid can enhance the tolerance of plants to non-biological stresses such as drought, salinity, low temperature, high temperature, and heavy metal pollution.
The mechanisms include: regulating the activity of antioxidant enzymes (such as SOD, POD, CAT), maintaining the stability of cell membranes, and promoting the accumulation of osmotic regulatory substances (such as proline, soluble sugars), etc.
3. Regulating plant growth and development
Low concentrations of salicylic acid can promote seed germination, root development and photosynthesis.
High concentrations, however, may inhibit growth, demonstrating the “hormone biphasic effect” (hormesis effect).
4. As part of the green control strategy
Although salicylic acid itself does not have the ability to directly kill pathogenic bacteria, it can reduce the use of chemical pesticides by inducing the plant’s own defense system.
It is often used in combination with other biological agents (such as chitosan, jasmonic acid) to enhance the efficacy.
Actual application forms
Leaf spraying: The common concentration is 0.1–1.0 mM (approximately 14–140 mg/L), which can be adjusted according to the type of crop and the purpose.
Seed treatment: Soaking seeds to enhance disease resistance and germination rate.
Mixing with pesticides: Enhancing the overall resistance of crops to diseases and prolonging the efficacy of the pesticide.
Notes for Attention
Excessive concentration may cause phytotoxicity (such as leaf burn and growth inhibition).
The effect is greatly influenced by environmental conditions (temperature, humidity), crop varieties and application timing.
Currently, salicylic acid has not been officially registered as a pesticide in China and most other countries. It is more commonly used as a plant growth regulator or a biological stimulant.
Summary
The core value of salicylic acid in agriculture lies in “protecting plants through plants” – by activating the plants’ own immune systems to resist diseases and adverse conditions. It is a functional substance that conforms to the concepts of green agriculture and sustainable development. Although it is not a traditional pesticide, it has significant potential in integrated pest management (IPM).
Post time: Nov-13-2025