Although growers are used to fight pests, molds, and fungi on their cannabis plants, there are some fungi that have beneficial effects on the growth of the plant and on the eventual yield. One of these is the Trichoderma Harzianum, that has the ability to colonize the rhizosphere of plants, causing an improvement in the development of the root system and the systemic defenses.
Another set of fungi that is beneficial to the growth of the plant are the arbuscular mycorrhizal fungi: soil microbiota that has been coexisting closely with plants over the last 455 million years. The arbuscular mycorrhizal fungi is also capable of developing symbiotic relationship with plants, including hemp. In a recent study, by Ioanna Kakabouki et al. from the University of Athens, have explored the interactions between these two fungi and their effect on the growth of the plant.
The authors carried out an experiment in a greenhouse using seedlings of ‘Uso’ cannabis variety, planted in pots. These were filled with soil and compost, and inoculated with Trichoderma Harzianum and arbuscular mycorrhizal. According to the authors, “the combined use of Trichoderma and Arbuscular provoked a synergistic effect, increasing root mass density, bud length and CBD yield per plant.” The scholars also noted that the root volume in the combined treatment of Trichoderma and Arbuscular was higher than the root volume registered in a Trichoderma only treatment.
Therefore, the author concludes that Arbuscular Mycorrhizal Fungi, if combined with Trichoderma Harzianum, cause a “significant increase in the root system, such resulted in improved plant yield and CBD yield as well as in the other agronomic characteristics such as the plant height and the dry matter.”
Source: researchgate.net