Using mushroom to protect the vines from other mushroom?

The 2023 vintage was terrible in terms of the proliferation of fungal diseases in our vineyards. In addition to downy mildew, which halved grape yields, we experienced several attacks of esca disease. But what is it specifically?

Grapevine esca disease is primarily contracted through wounds caused by agronomic operations, such as pruning, wounds caused by dry wood, or simply conditions that are particularly favorable for the disease to proliferate. The fungus responsible include species in the genera Phaeomoniella, Phaeoacremonium and others, which penetrate the exposed wood, compromising the vascular system of the plant causing leaf wilt, shoot death and plant death.

Unfortunately, fighting it is extremely difficult, if not impossible. The only successful cure would seem to be to explant the vine and plant a new one.

We, as winegrowers, can only prevent it, but how exactly?

We recently carried out the first phytosanitary treatments in our vineyards, using a product that will surprise many: fungi, specifically Trichoderma. Exactly, we used fungi to prevent the infection of other fungi, doesn't that sound absurd?

Trichoderma is a kind of fungi used as a biocontrol agent to fight grapevine esca disease, but how exactly does it work?

• Trichoderma acts primarily through competition and antagonism against pathogenic fungi. It produces antimicrobial and antifungal enzymes that damage the cell walls of pathogens, preventing them from growing and spreading

• Trichoderma can colonize the same sites as pathogenic infections, competing with them for resources and reducing their ability to damage plants.

• Trichoderma in addition shows a capacity for chemotropism, which is the ability to move toward specific chemicals released by plants or pathogens. This allows it to more effectively localize infected areas and focus its antifungal action where it is most needed. Because of this trait, Trichoderma can respond in a targeted manner to plant stress situations and fungal infections, enhancing its protective effect against esca disease.

• Trichoderma stimulates the plant's defense responses, causing it to produce chemicals that can protect it from fungal infections.

In other words, Trichoderma is a true ally toward what our concept of viticulture is: promoting a symbiotic and natural balance to produce great wines.

The leaf affected by bait disease shows the first symptoms around June; by late August it will be completely desiccated. From that time all that can be done is to explant the plant and burn the infected vine stock.