The day began with a presentation by Doctor Patrick Du Jardin, a major, world renowned scientist in the field of bio-stimulation
The Bioinsecticides – Idai Nature Chair of the UPV has organized a seminar with top notch speakers with the aim of delving deeper into the physiological mechanisms and underlying metabolism by which biostimulants enable increased tolerance to situations of abiotic stress, thus promoting their development.
These are the 10 main conclusions:
1. Initially, biostimulants were defined as: products applied to plants to increase crop yields and quality. Their main function was not to supply nutrients (like fertilizers do) or to protect plants from pathogens and pests (like protection products do).
2. Biostimulants have several natures:
a. Substances (humic substances, plant extracts, hydrolyzed proteins and amino acids, chitosan and other polysaccharides and inorganic compounds)
b. Microorganisms (Bacteria and fungi)
3. The EU draft on fertilizers regulated by the EU, defines the concept of ‘Biostimulant’ as:
“A biostimulant is a product that stimulates plant nutrition processes regardless of the product’s nutrient content and the sole objective of which is to improve one or more of the following plant characteristics or the plant’s rhizosphere”:
a. Efficiency in use of nutrients (NUE).
b. Tolerance to abiotic stress.
c. Quality characteristics.
4. Nutrient use efficiency. Biostimulants can increase it via root growth, nutrient solubilization, nutrient input, translocation and nutrient distribution, modifying photosynthetic capacity, stress tolerance, etc.
5. Tolerance to abiotic stress; it can have three different mechanisms of action:
a. Occurs when faced with stress (activation of the ‘priming’ system)
b. During stress
c. After stress (recovery).
An increase in yield is expected when plants experience stress and no decrease in yields is expected in the absence of such stress.
6. Quality characteristics, which will be manifested in pre- and post-harvest or via regulation of primary and secondary metabolism.
7. The main challenges faced by biostimulants are:
a. Scientific: understanding the mechanisms of action of biostimulants, their interaction with plants and other environmental factors. In addition, it is necessary to close the gap between laboratory data and field data.
b. Technical: guarantee the effectiveness in the field and develop an adequate management together with the farmers, inserting the biostimulants in a framework of “precision agriculture”.
c. Regulatory: create comprehensive, scientifically-based regulations that facilitate access to the market and guarantee products’ safety and efficacy.
8. Biostimulants are activators of plants’ physiological processes, but greater knowledge of them is still required to attribute the importance they deserve within the market.
9. Mycorrhizae present the following benefits:
a. Enhance uptake of mineral nutrients from soil (P).
b. Provide greater tolerance to biotic and abiotic stresses
c. Facilitate the movement of nutrients
d. Improve soil physical-chemical properties of the soil.
e. Improve rooting and establishment of plants
f. Promote the diversity of plant communities.
10. Mycorrhizae are essential components for enhancing the resilience of plants against forms of stress induced by climate change: drought, temperature, salinity, pollution, deficit of nutrients and diseases and pests
