The importance of corroborants in the vegetative recovery of the olive tree

With the vegetative recovery it is essential to use corroborants to support the growth of olive trees and optimize the 2025 production campaign. Tonics are not fertilizers, but they strengthen the natural defenses of plants., making them more resistant to pests, diseases and harsh climate conditions.

What does 'strengthening natural defenses' mean?

Plants have a defense system that protects them from threats such as fungi, bacteria or environmental stress, such as drought or extreme temperatures. Tonics stimulate this system, promoting healthier and more stable development through mechanisms such as:
1. activation of plant immune responses
Plants have a defense system called “innate immunity”, which is activated by signal molecules such as salicylic acid, jasmonic acid or abscisic acid. Tonics stimulate the production of these molecules, amplifying the plant's ability to activate defensive reactions such as: synthesis of antimicrobial compounds such as phytoalexins, polyphenols, terpenoids, which inhibit the growth of pathogens, deposit of lignin or cellulose in cell walls to make it more difficult for pathogens to penetrate.

2. Physical and chemical barriers
Some corroborants, such as silica gel, zeolite, talc, form a protective barrier on the plant surface. These barriers can prevent the establishment of fungal spores or the deposition of eggs by insects. They are also able to modify the microenvironment of the plant surface, making it less favorable to the growth of pathogens, such as sodium bicarbonate which varies the pH of leaf surfaces.

3. Support secondary metabolism
Many tonics, such as flavonoids or algae extracts, stimulate the secondary metabolism of plants, which is responsible for the production of molecules useful for defending them from parasitic attacks and fatigue from drought, high temperatures, supporting the general well-being of the olive tree.

In all these cases, tonics help plants with:

• Resistance to fungi and insect parasites
  Some tonics have a preventive action, improving the resistance of plants, for example, the use of propolis or wood distillate helps to inhibit microbial growth thanks to their bacteriostatic and fungicidal properties. Kaolin or zeolite, which are rock powders, form layers on the vegetation that disturb the behavior of insects, for example by hindering the oviposition of the olive fly.
•  Difficult environmental conditions
  In these cases, some tonics, such as glycine betaine, can act as water regulators within the plant, helping to avoid dehydration in drought or salinity conditions.
  Another example is that algae extracts also promote better water retention in plant tissues.
  Again, rock powders such as kaolin, which reflect sunlight, reducing leaf temperature and minimizing heat damage on particularly hot days.
• Recovery of vegetative vigor
  Other tonics, such as ozonated oils, are vegetable oils treated with ozone that develop antimicrobial actions, help tissue regeneration and stimulate the natural defense processes of plants. Thanks to their ability to improve the general health of plants, they can be useful in situations of environmental stress or after physical damage.

SUMMARY TABLE

AIPO Director
Interregional Association
Olive producers