What are plant biostimulants?
Introduction
Recent years have shown a clear increase in demand for plant biostimulants across the board as an alternative to chemicals. They are considered more environmentally friendly and, as the results show, have high efficiency. This makes farms want to buy and create such a high demand. The global plant biostimulant market is estimated at approximately $2.19 billion, and its annual growth is about 12.5%. Although Europe and North America are considered the largest market, trends show that interest in plant biostimulants is growing in other parts of the world.
What are plant biostimulants?
The term “biostimulant” can be confusing because there are legal or regulatory definition. Many experts have tried to define it in a way that separates biostimulants from fertilizers, pesticides, and biocontrol agents. This was done to help governments create clear regulations for biostimulants.
– The confusion increases because some biostimulants perform multiple functions.
For example:
Some act as biostimulants and also help control plant diseases (biocontrol agents).
Others are mixed with fertilizers, making them difficult to classify.
This overlap makes it difficult to create a single definition that applies to all biostimulants.
In December 2018, the first statutory language regarding plant biostimulants was provided in the Farm Bill.
A plant biostimulant is any substance or microorganism that, when applied to seeds, plants or soil (rhizosphere), stimulates natural processes to improve nutrient uptake, nutrient efficiency, stress resistance or overall crop quality and yield.This legal definition of plant biostimulants is an important step towards creating a regulatory framework for their review, approval and standardised national labelling. Currently, these materials are classified as fertilisers, soil inoculants or soil additives at the national level. The definition introduced in the 2018 Agricultural Act is in line with the definition proposed by the European Union.
Biostimulants come in a variety of formulas with a variety of ingredients. Some of the most commonly used ingredients include humic and fulvic acids, seaweed extracts, beneficial bacteria and fungi. Other formulas may include chitosans (a water-soluble form of chitin), protein hydrolysates and inorganic compounds such as silicon. Of these, the most widely used are acid-based biostimulants.
For a long time, plant biostimulants were thought to have no effect and were called “snail oil”, but many studies now show that there are more effects and see real results of using biostimulants.
Essentially, any biostimulant will consist of one of humic substance or seaweed extracts, or both in one product.
Decomposed organic matter provides humic substances, which are typical components of soil that enhance root development, nutrient uptake, and soil structure. They come from renewable resources like compost and vermicompost, which tend to be more efficient than nonrenewable ones like peat and coal.
Beneficial polysaccharides, phenolics, and phytohormones can be found in seaweed extracts, which mainly come from brown seaweeds such Ascophyllum and Laminaria. They improve soil water retention while boosting plant growth, nutritional uptake, and disease resistance.
Essentially, any biostimulant will consist of one of humic substance or seaweed extracts, or both in one product.
Decomposed organic matter provides humic substances, which are typical components of soil that enhance root development, nutrient uptake, and soil structure. They come from renewable resources like compost and vermicompost, which tend to be more efficient than nonrenewable ones like peat and coal.
Beneficial polysaccharides, phenolics, and phytohormones can be found in seaweed extracts, which mainly come from brown seaweeds such Ascophyllum and Laminaria. They improve soil water retention while boosting plant growth, nutritional uptake, and disease resistance.
What does the research say?
Most data on these products is for high value of biostimulate for plants. dies. The application of biostimulant not only enhanced the growth of corn seedlings and stem cuttings of tomato , but also improved nutrient status, yield, and quality of herbaceous and woody plants, including corn, bean, tomato, sweet yellow pepper, strawberry, banana, papaya, and red grape . It also enhanced tolerance to a wide range of abiotic stresses, such as drought , salinity extreme temperatures, nutrient deficiency, and adverse soil pH . The application of biostimulant increased root morphology, such as root dry mass, total root length, and root surface area, which was associated with improved nitrogen status.
The study at Purdue University (2017–2018) studied how auxin and biostimulants produced by plants affected the growth of roots in cuttings of tomatoes, chrysanthemums, and basil.The results showed, in contrast to auxin, which created thicker roots, biostimulants promoted the development of finer roots by increasing root growth, particularly at 5,000 mg/L. Unlike high concentrations of auxin, biostimulants did not harm even at 10,000 mg/L. Additionally, by boosting antioxidant activity, biostimulants improved stress tolerance, particularly in chrysanthemum. Their effects were linked to auxin-interacting pathways mediated by brassinosteroids (BR). All things considered, biostimulants were useful for commercial plant multiplication since they promoted root growth and plant resistance.
In addition to disease tolerant biostimulants, an incredibly compelling reason for improving temperatures, improving rot rates, and improving the overall weather conditions that plants can tolerate has been shown.
