Paraglomeralean fungi

Paraglomeralean fungi (order Paraglomerales) belong to the phylum Glomeromycota. It is crucial to clarify that these organisms are not plant pathogens or disease agents, but rather beneficial symbionts.

These fungi form arbuscular mycorrhiza (AM) with the roots of a wide range of terrestrial plants. This symbiotic relationship is essential for the natural development and nutrition of crops.

The fungi live within the root cortex, where they exchange sugars derived from the host plant for mineral nutrients, primarily phosphorus, which the fungus gathers from the soil.

There are no known symptoms of disease caused by Paraglomerales. They do not cause tissue damage, chlorosis, or any physiological decline in plants.

Mistaking these fungi for pathogens is a common misconception in field diagnostics, as their presence within the root structure is a positive biological indicator of soil fertility.

The development of Paraglomerales is strictly dependent on the presence of living plant roots, as these organisms are obligate symbionts and cannot complete their life cycle as saprotrophs.

Optimal conditions for fungal colonisation include well-aerated soils with moderate moisture levels, allowing the extensive network of hyphae to explore the soil matrix effectively.

High levels of readily available phosphate fertilizers can inhibit the formation of mycorrhizal associations, as the plant reduces its dependency on the fungal symbiont under high-nutrient conditions.

Soil temperature is a key factor, with peak fungal activity typically observed during the active growing season, when root metabolism is highest.

Low-disturbance soil environments, such as those maintained under no-till practices, provide the best conditions for the preservation and expansion of the fungal network.

There is no harm associated with Paraglomeralean fungi; they are considered beneficial soil organisms rather than pests or pathogens.

These fungi do not reduce crop yields; instead, they act as a biological boost, enhancing the plant's ability to tolerate drought, salinity, and soil-borne diseases.

Because they are not pathogenic, there is no economic threshold for damage, and their presence is welcomed as a component of healthy and sustainable agricultural systems.

Reports of negative impact are non-existent in agronomic literature. Their influence on agricultural production is overwhelmingly positive due to the increase in nutrient uptake efficiency.

In modern agronomy, the loss of these fungi due to intensive tillage or soil sterilization is considered detrimental to long-term crop health and soil quality.

As Paraglomerales are beneficial components of the soil microbiome, there is no control program required. Management strategies focus on supporting rather than eliminating these fungi.

Good agricultural practices that promote soil microbial life will naturally favor the development of these mycorrhizal networks.

Reducing the frequency and intensity of chemical treatments, especially fungicides that might have off-target effects on non-pathogenic fungi, helps maintain mycorrhizal integrity.

Effective management includes crop rotation and the use of cover crops, which ensure a continuous presence of living roots to sustain the fungal population.

• Adopting no-till or reduced tillage farming.
• Optimizing fertilizer use to encourage natural symbiosis.
• Prioritizing biological inputs over harsh chemical treatments.
• Using cover crops to maintain soil microbial activity.