As a grass plant grows and evolves, it is met with many obstacles that could interfere with a healthy growth cycle. Abiotic stress is a non-living environmental factor that interferes with the growth cycle of plants and their maturation. Some relevant examples of abiotic stress are drought, salinity, temperature fluctuation, nutrient deficiencies, and high winds, but there are many more. Whereas, living disturbances known as biotic stress factors are seen as insects and diseases. The significant impact of these abiotic stress factors ultimately hinders the performance and physiology of a plant. An effective way to counteract these interferences is the use of biostimulants.
Biostimulants are substances or microorganisms that enhance the plant growth process and increase stress resistance. This can come in the form of directly affecting the plant or improving the soil conditions in which the plant lives. In fighting the various abiotic stress factors that a plant will endure, the biostimulants will alter the plant’s metabolism in response to the abiotic stress factors while helping to speed up this process and make it more efficient. Typically, biostimulants will not have much effect on biotic stress factors like pathogens or pests, but they are extremely helpful for abiotic stress factors.
Types of Biostimulants- Humic and fulvic acids
- Seaweed extracts
- Protein hydrolysates
- Beneficial bacteria and fungi
Humic and fulvic acids are groups of molecules that help the root systems by binding to them and increasing nutrient uptake while reducing leaching. Humic acids pick up positive cation charges and are attracted to the negative charges that the plant’s root zone gives off. By doing this, they are increasing the availability of nutrients by chelating magnesium, calcium, and iron. Applications can be made with liquids or granular products. Liquid products tend to yield the best results, but concentrated granular lime products can have increased humic acids added to them. The best time to make these applications is the spring and fall seasons when the root systems are most active.
Seaweed extract applications are usually done as a preventative measure and as a first line of defense against stress. They deal more with hormone imbalances by acting as signal molecules that trigger the protective mechanisms in plants. Auxin and cytokinins are phytohormones in the plant that affect the regulation of plant growth. Seaweed has auxin and cytokinin activity, so when stress levels lower these hormones, the seaweed is there to help boost them back up and get the plant back on track.
Protein hydrolysates are amino acids and peptides that have been broken down from their original protein. Protein hydrolysates focus more on the recovery aspect by building the plant’s natural health back. Amino acids are important for the growth and maturation of a plant and are used in many various production points, such as the cytoplasm, the mitochondria, and the chloroplasts. Studies show that they increase carbon and nitrogen assimilation, chlorophyll production, and increase the production of other essential amino acids. In the past, typical applications included low doses of multiple amino acids. A great deal of research has been done recently about which amino acids work best with plants, and we have been able to narrow that down and focus on getting the plants the proper acids in higher doses to help them flourish.
Beneficial bacteria added to the soil can help abiotic stress factors by increasing nutrient uptake by solubilizing mineral phosphates and other nutrients. They can help produce natural antibiotics and compete with other pathogens for resources, which in turn will reduce biotic stress levels. Beneficial bacteria can also produce hormones like auxins and cytokinins that help in the plant’s growth. Beneficial fungi have many supporting factors, which include nutrient uptake, soil structure improvement, increased water uptake, and disease protection. One example of this is mycorrhizal fungi. Mycorrhizal fungi bind to the root systems of a plant and seek out phosphates (and other nutrients) to help deliver them to the plant more efficiently. The increase in phosphorus will also help to boost the growth of the root system. This creates a symbiotic relationship between the plant and the fungi. By attaching to the roots, it helps protect against other fungal diseases and creates a natural defense system. The fungi can also create space for more water and air to reach the root systems and help with soil compaction.
The use of biostimulants and their research has come a long way over the past decade and will continue to grow as stress levels continue to affect our industry. We can’t control Mother Nature, but we can be ready to mitigate the damage and stress that comes along with it. Biostimulants are a great way to reduce the overuse of chemicals and reduce harmful environmental impacts associated with them. They are best applied in the spring as a preventative measure to increase defense so that the plant is prepared when a stressful event occurs.