Grapevines in partnership with fungi

I've been reading a fascinating book called Mycophilia by food writer and cookbook author Eugenia Bone. She stoked my interest in everything mushroom. I have been most interested in the symbiotic relationship between underground mycorrhizal fungi and photosynthetic plants above ground. Some fungi serve to remove and clean-up diseased and dying plants. Others have symbiotic relationships with specific plants they tend to. Their root systems get intertwined, the plants delivering sugars to the fungi, the fungi extracting minerals from the soil and delivering them to the roots of plants.



When soil is disturbed, the fungi can die and so does the vegetation associated with them. It stands to reason then, that when you plant something new from seed or sterilized root stock in a prepared garden, you are planting only half the partnership. The new planting could be slow to take, and some never do.

We stopped buying bare root trees from nurseries after the first year. Many of the trees we planted died and others are just beginning to grow a decade later. On the other hand, trees we harvested from our own land that had self-seeded in gravel or grass did exceedingly well when transplanted. That could be because their roots were colonized with the kinds of organisms they liked to associate with.

The relationship between fungi and plants can go the other way, too. A couple of years ago, we learned that a specific wild orchid can contain and control honey fungus, a parasitic and highly destructive Armillaria spp. Since we received some fuscia bushes from a farm later found to be contaminated with honey fungus, we planted these orchids all around our gardens, and so far so good. As it turns out, honey fungus is fascinating. They found one they think is the largest and oldest living organism on earth. Some scientists think it kills trees it associates with, others think its job is to 'disassemble' already diseased or decaying plant matter.

Naturally I started to investigate if grapevines are associated with specific mycorrhizal partners. Lo and behold, I came upon an article by Andre Meyer in WineLand from 2007. He concluded that "Arbuscular mycorrhizal fungi are wholly natural components of the micro ecology of vineyard soils. They have the ability to improve nutrition and root resistance to attack by pathogens, and also contribute positively to soil structure and stability. The beneficial effects of AM fungi in vineyards are nevertheless largely unappreciated at present. Recognition of their importance as components of healthy soils, and the implementation of practices that favour their propagation, are important aspects of vineyard management."

Given that we planted our vines in a green field that had been used for grazing sheep, cattle, horses, and donkeys for many years, it stands to reason that the soil structure has been disturbed and needs to recover. Perhaps we can find a way to assist. I found a company called Empathy that specializes in biological products for gardens, one called RootGrow, available (of course) on Amazon.com.  I found a review article from 2015 about the subject and will now have to learn more.

According to Meyer, cover crops can also assist. Cover crops play host to a wide range of AM fungi. They set in motion an underground process of hyphal growth and spore production. Pieces of colonized root, spores and hyphae that have survived in the soil from the preceding season all act as sources of inoculum for the cover crop. As the root systems of the cover crop and grapevine become intertwined, fresh supplies of inoculum are passed on to the grapevine.

Now to learn about which cover crops to sow. I feel another post coming on.