From toxicity mitigation to drought tolerance, mycorrhizal relationships between plants and fungi stand to benefit growers as an easy production choice for their nursery crops. We caught up with Scott Inman, Director of R&D, Regulatory, and Facilities at Mycorrhizal Applications, to learn some of the benefits of using mycorrhizal fungi.

How can mycorrhizal fungi help growers maximize nutrient uptake and overall plant nutrition?

The symbiotic relationship between the plant and the mycorrhizal fungi maximizes nutrient uptake because the mycorrhizae create a hyphal network (a.k.a. mycelium) within the root zone that has the ability to capture nutrients in the growing media or soil that are otherwise unavailable to the plant. The mycorrhizal hyphae effectively increase the absorptive surface area of the roots (50x) by acting as a living extension and capturing more of the nutrients applied by the grower, so less fertilizer gets flushed through the pots. Mycorrhizae also have the ability to capture both the bioavailable and tightly bound forms of the nutrients by solubilizing unavailable forms of key nutrients and delivering them directly to the plant. The mycorrhizae provide nutrients to the plant in exchange for carbon, and growers benefit from this fundamental symbiosis in the form of nutrient efficiency.

How can mycorrhizae help plants become more drought-tolerant?

The mycorrhizal mycelial network actively sources and delivers water directly to the plant and has different mechanisms to support a plant’s drought tolerance. The mycelium’s hyphal strands have the ability to absorb water along the entire length of their hyphae and deliver it directly to the plant’s vascular system, increasing absorptive surface area. The hyphae are a lot smaller than roots and can penetrate pore spaces that the root cannot. And most importantly for drought tolerance, the mycorrhizae can store water for times of drought, both within the mycelium itself, which stores water like a sponge, but also in structures called vesicles that endomycorrhizae form within the root cells which store liquid in the form of lipids that the plant can access in times of need.

During times of extended drought stress, the plant is able to be much more efficient overall because it doesn’t need to invest as much in root growth to try to locate additional water in the rhizosphere. The mycorrhizae is investing in doing the growing, using the carbon that the plant provides in exchange for water and nutrients. Therefore, the plant doesn’t have to expend the same amount of energy when resources are scarce, once that mycorrhizae association has already been developed, and it has access to the assistance provided by the symbiotic fungal partner.

How can mycorrhizae mitigate toxic soils? What are some other soil health benefits?

In this drought trial, on average the MycoApply treated plants were able to withstand wilt for 24-36 hours longer between watering intervals. The coreopsis on the right was treated with MycoApply and the plant on the left was untreated.
Photo courtesy of Mycorrhizal Applications

Mycorrhizae can grow, penetrate, and colonize plants in different soils and filter out toxic elements to protect their plant partners. The mycorrhizae absorb the toxic elements such as heavy metals or sodium, which may have been present in the water or in the soil/media, and the fungi will hold the toxic elements, and then transport the beneficial nutrients and water to the plant. You end up with a plant that actually can function and be productive in conditions that otherwise would be toxic, due to this buffering effect of the mycorrhizae.

What should growers know about application for the best outcome?

The key to the best outcome is simple: just make sure that the mycorrhizal inoculant gets applied in a way that puts the active ingredients directly into the root zone, because that is where the symbiotic relationship is formed. Once growers get it into their root zone, the plant will drive the relationship based on its needs.

With our MycoApply line of professional inoculants, growers have a diverse array of efficient application options, including soil/media incorporation, soil drench, plug/propagation tray drench, drip irrigation, boom spray, bare root treatment, and many more.

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