Page 19 - Griffin Gazette Issue 2 - 2019

MYCORRHIZAE IMPROVES PLANT
SURVIVABILITY AND VIGOR
Mycorrhizal fungi inoculants have been available from Premier
Tech for various uses for over twenty years, either in growing
media (PRO-MIX MYCORRHIZAE products) for the production
of horticultural crops or in more concentrated formulations
that can be applied directly in fields at planting or mixed into
growing media used and in nurseries or incorporated into the
soil when installing landscapes (MYKE products).
Although the importance of mycorrhizae has been amply
demonstrated for decades, most plants sold by greenhouse
and nurseries are not pre-inoculated with mycorrhizae, unless
the growing medium contains mycorrhizae. In disturbed
soils, mycorrhizae do not develop naturally or re-establish
themselves in soil. Adding such microorganisms has a
positive impact on plant production, reduction of transplant
shock and recovery of plants after transplanting. Interestingly,
once plants are inoculated with mycorrhizae, these beneficial
fungi stay with and benefit the plant for life.
While the impact of a fertilizer on plant growth is immediate,
Figure 1. Picture of roots (larger structures) with the effect of a mycorrhizal inoculant will often be evident later
mycorrhizal network (smaller threads). Mycorrhizal fungi in the crop cycle, when the plant experiences stress from
are microscopic so this picture is enlarged 40 times with a excessive or lack of fertility, heat, lack of water, environmental
microscope. Source: Premier Tech Horticulture conditions, etc. Plants grown in a greenhouse or nursery
are generally watered and fertilized in accordance to their
needs. Often, they do not experience high stress, in which
mycorrhizae can benefit them. It is only when these plants leave
SOILS DISTURBED BY URBANIZATION the greenhouse or nursery that they are likely to experience
Urban landscaping in recent years, is challenged by urban stresses that can be detrimental to their development.
heat islands that are generated with the use of concrete Adding mycorrhizae minimizes these environmental impacts
and asphalt surfaces in city environments. This means that to improve the establishment of plants, the overall growth
the plants selected for these locations must be reviewed performance and plant survivability.
periodically to ensure they can survive in these landscaped
areas with extreme temperatures, drought, human activity,
etc. The soil must also be considered when it comes to
plant survival, as it plays a crucial part in the retention of
water and health of plants, especially for trees and shrubs,
whose life cycle is longer than annuals. The organic matter,
microflora and other organisms, such as earthworms, are
essential factors in soil fertility and play a major role in the
plant establishment success.
Adequate microbiological diversity in the soil helps maintain
the soil's structure, which aids in the retention of water and
nutrients. For example, it has been recently shown that
phosphorus can be made available for plants from apatite (a
group of phosphate minerals) through the interaction between
mycorrhizal fungi and specific bacteria (Québec Science,
January-February 2016).
Unfortunately, urbanization and human activity disturb the soil
and greatly reduce the quantity of mycorrhizal propagules it
contains naturally. Soil amendments such as peat moss, bark,
compost and humus do not contain the types or sufficient
quantities of mycorrhizae required by most ornamental and
vegetable plant species. By adding them to the soil, plants Figure 2. Calibrachoa cuttings were rooted in the same
adjust to harsh climate and soil environment for better growing media, except the tray on the right had mycorrhizal
survivability and plant growth. fungi incorporated. Notice the difference in growth. Those
with mycorrhizal fungi are ready to transplant faster than
those without. Source: Premier Tech Horticulture.

GRIFFIN GAZETTE 2019 | 19