Frequently Asked Questions about Biostimulants in Grapevines

Introduction

Grapevine production faces numerous challenges, from adverse weather conditions to diseases and pests. To help growers tackle these challenges, biostimulants have emerged as an effective solution. In this article, we will answer the most frequently asked questions about the use of biostimulants in grapevine production, providing valuable information to help you improve your crops.

What are biostimulants?

Biostimulants are substances or microorganisms that, when applied to plants, enhance their growth and development by boosting physiological processes. These products can be of natural origin, such as plant extracts and beneficial microorganisms, and are designed to optimize plant health and agricultural productivity.

Types of biostimulants

• Plant extracts: derived from plants that stimulate crop growth and health.
• Beneficial microorganisms: bacteria and fungi that improve nutrient uptake and disease resistance.
• Bioactive compounds: substances that promote metabolic activity in plants.

Microorganisms as biostimulants

Beneficial microorganisms, such as bacteria and fungi, are fundamental in sustainable agriculture. These organisms can colonize plant roots and form symbiotic associations that improve nutrient uptake. For example, bacteria of the genus Rhizobium can fix nitrogen from the air, converting it into a form usable by plants, which is especially useful in nutrient-poor soils. Additionally, other microorganisms like Mycorrhizae help increase the root absorption surface area, facilitating the uptake of phosphorus and other essential micronutrients.

Bioactive compounds

Bioactive compounds, such as humic and fulvic acids, are essential for improving soil structure and nutrient availability. These compounds not only promote plant growth but also help retain soil moisture, which is critical in regions with water scarcity. Research has shown that the application of humic acids can increase the soil's water retention capacity by up to 30%. Furthermore, fulvic acids help chelate nutrients, making them more accessible to plants, which can improve fertilizer use efficiency.

Mechanisms of action of biostimulants

Biostimulants act through various biochemical and physiological mechanisms. For example, some plant extracts can increase the production of phytohormones, such as auxins and cytokinins, which are essential for plant growth and development. Other biostimulants can enhance the activity of enzymes involved in plant metabolism, facilitating nutrient assimilation. A study conducted by the University of Córdoba showed that the application of a seaweed-based biostimulant increased the activity of the nitrate reductase enzyme in grapevine leaves, resulting in a 20% increase in nitrogen uptake. Additionally, some biostimulants have been observed to induce systemic acquired resistance, a mechanism that allows plants to respond more effectively to pathogens and environmental stress.

Relevant studies on biostimulants in viticulture

Several studies have documented the positive impact of biostimulants in viticulture. A trial conducted in the Bordeaux region of France revealed that the application of a biostimulant based on seaweed extracts increased grape production by 25%, in addition to improving the quality of the resulting wine, with an increase in anthocyanin levels, responsible for the wine's color and aroma. Another study in Chilean vineyards demonstrated that the use of amino acid-based biostimulants increased sugar accumulation in grapes, resulting in a wine with higher alcohol content and a more complex organoleptic profile.

Benefits of biostimulants in grapevines

Biostimulants offer multiple benefits in grapevine cultivation, including:

• Improved grape quality: by optimizing nutrition and metabolism, biostimulants can increase the content of sugars and aromatic compounds in grapes, resulting in higher quality wines. Research has shown that the use of biostimulants can increase polyphenol content by 15-30%, improving the organoleptic properties of the wine.
• Increased stress resistance: biostimulants help plants tolerate adverse conditions, such as drought or extreme temperatures. A study conducted in vineyards exposed to drought conditions found that biostimulant treatments increased plant survival rates by 40% compared to controls. Additionally, some biostimulants have been shown to induce the production of secondary metabolites that protect plants from dehydration.
• Stimulation of root growth: a more developed root system improves water and nutrient absorption, leading to better performance. The application of biostimulants can increase root length by 25%, allowing plants to access a greater amount of soil resources. A study conducted in vineyards in Mendoza, Argentina, showed that the use of a microorganism-based biostimulant increased root biomass by 35% compared to the control.

Impact on soil health

The use of biostimulants not only benefits plants but also improves soil health. By promoting microbial activity and improving soil structure, biostimulants contribute to a more balanced agricultural ecosystem. A study in Tuscan vineyards showed that the application of microorganism-based biostimulants increased soil microbial diversity by 50%, highlighting the importance of soil management for optimal berry production.