Bacillus subtilis grows fast. It can produce heat-resistant and stress-resistant spores. It can be made into various dosage forms. It can mix with chemical pesticides without inactivation, and the mass production process is simple, the cost is low, and the application is convenient and storage.
The effects of Bacillus subtilis on plants are mainly reflected in the following aspects:
1.Nutrition and space competition
The competitive effects of Bacillus subtilis mainly include nutritional competition and spatial locus competition. It can rapidly and massively multiply and colonize in the rhizosphere, body surface, or the soil and in the soil, forcefully reject, prevent and interfere with the colonization and infection of plant pathogenic microorganisms on plants, thereby achieving antibacterial and disease-preventing effects.
2.Produce antibacterial substances
Bacillus subtilis can produce a variety of materials with antibacterial and bacteriostatic activities during the growth process, such as subtilin, organic acids, antibacterial proteins, etc. These substances can inhibit the growth and reproduction of pathogenic bacteria and even destroy the bacterial structure and kill Pathogens. Therefore, Bacillus subtilis has a good effect on the prevention and treatment of diseases such as double rot, root rot, and gray mold.
3.Increase crop’s immune system and growth
Bacillus subtilis can secrete active substances, activate plant defense systems, enhance crop immunity and disease resistance, and reduce or eliminate the harm of pathogenic bacteria to plants.
It can also promote the growth and development of a variety of plant seeds, seedlings, and roots, and enhance the disease resistance of plants, thereby indirectly reducing the occurrence of diseases. Such as the increase in the formation of auxin such as indoleacetic acid, stimulate crop root development, and enhance photosynthesis. At the same time, the materials that are difficult to absorb in the soil are converted into substances that are easy to be absorbed by the crops, and the absorption and utilization of nutrients by the crops are promoted. The utilization rate of the fertilizers is improved.
4.Induce plant resistances to diseases
Bacillus subtilis not only directly inhibits plant pathogenic bacteria but also enhances plant disease resistance by inducing the plant’s disease resistance potential. For example, B. subtilis, a biocontrol agent against rice sheath blight, can produce the activity of enzymes (POD, PPO, and SOD) related to disease resistance of rice leaf sheath cells, and achieve disease resistance.