Biostimulants are natural or synthetic substances that can be applied to seeds, plants, and soil. These substances cause changes in vital and structural processes in order to influence plant growth through improved tolerance to abiotic stresses and increase seed and/or grain yield and quality.
In the journey toward sustainable and robust agriculture, plant biostimulants emerge as silent yet potent allies. These natural compounds, each with its unique prowess, play a pivotal role in enhancing the vitality of plants, especially in the realm of apple orchards.
What Are Biostimulants?
Imagine Biostimulants as the wellness boosters for plants. Unlike fertilizers that directly provide essential nutrients, biostimulants work as growth promoters, improving nutrient absorption, stress tolerance, and overall plant health. They are derived from various natural sources and come in different forms, each tailored to address specific aspects of plant development.
Biostimulants can influence a plant’s vigor and yield but do not manage or protect against pests and other detrimental factors to plant quality like weeds, disease, or insects. They are also in a separate category from Plant Growth Regulators, which are chemicals that alter plant growth.
Types of Biostimulants
- Protein Hydrolysates : These compounds, extracted through chemical and enzymatic methods, harness the power of amino acids and peptides. Think of them as the building blocks of protein, essential for robust plant growth.
- Humic and Fulvic Acids: As organic matter breaks down in the soil, it gives rise to humic and fulvic acids. Derived from plant, animal, and microbial residues, these acids contribute to soil health and nutrient availability.
- Seaweed Extracts & Botanicals: Seaweed extracts, a time-tested remedy, enhance water retention in soils. These botanical wonders, when employed in agriculture, bring a wealth of benefits to plant growth and resilience. When used in soils, seaweed can increase water retention.
- Chitosan & Other Biopolymers: Armor Against Stress. Chitosan, derived from chitin, fortifies plants against environmental stressors. Its application boosts a plant’s ability to withstand varying weather conditions, ensuring a stalwart defense.
- Inorganic Compounds: Minerals for Might. Elements like silica, selenium, cobalt, sodium, and aluminum act as fortifying agents. They strengthen cell walls and stimulate growth, contributing to the overall vigor of the plant.
Benefits of Biostimulants
- Enhancing Nutrient Uptake: Biostimulants act as efficient carriers, aiding in the absorption of essential nutrients by plant roots. This results in a well-nourished and flourishing plant.
- Boosting Stress Tolerance: Apple orchards face various stresses – weather fluctuations, diseases, and nutrient imbalances. Biostimulants equip trees to handle these challenges, ensuring a more resilient and productive orchard.
- Improving Soil Structure: Humic and fulvic acids contribute to soil health by enhancing its structure. This, in turn, facilitates better water retention and nutrient availability for plant roots.
- Enhanced Root Growth: Seaweed extracts, rich in growth-promoting hormones, stimulate plant growth and development. This contributes to robust root systems and overall plant vigor.
- Increased Fruit Set & Quality: Inorganic compounds play a role in fortifying cell walls, providing structural integrity to plant cells. This fortification is vital for withstanding external pressures.
- Sustainable Farming: Biostimulants are nature’s way of promoting sustainable agriculture. By harnessing the power of organic compounds, growers can enhance productivity without relying heavily on synthetic chemicals.
Effect of biostimulants on apple & cherry trees
Research studies have shown that the pre-harvest applications of biostimulants (based on seaweed extracts and inorganic compounds Zn and Si) in combination with Ca can enhance the esthetical quality of apple fruits at harvest by increasing the intensity of skin color and can also reduce the incidence of storage disorder. Seaweed and protein hydrolysates enhance the red color of apples cultivated in open field conditions, independently from the seasonal weather conditions and the cultivation area. Humic acids & fulvic acids applications increase fruit quality (sugar content, anthocyanin concentration and fruit size), whereas seaweed application reduces the incidence of cherry cracking due to rainfalls before harvest.
Finally, selected biostimulants have shown some potentially interesting properties to be exploited for the management of the fruit storage period. As an example, the increased concentration of phenolics and other antioxidant compounds, found in apples treated with silicon and zinc-based biostimulants, is responsible for the lower incidence of post-harvest disorders in apple fruit at the end of the storage period.
As apple growers, our aim is to cultivate excellence – from the roots to the fruit. Plant biostimulants are the natural partners that empower us to achieve this goal. By integrating these wonders into our orchard care routine, we not only enhance the health of our trees but also contribute to sustainable and bountiful apple harvests.
Understanding the specific needs of your orchard and consulting with agricultural experts can guide you in choosing the right biostimulant for optimal results.