What’s new in greenhouse cannabis research?
Stressing overall plant health, integrating beneficial microbes and organic nutrients not only promotes robust growth but enhances cannabinoid production, according to some of the latest research on the topic. Additionally, using sensors to monitor environmental factors including humidity and temperature ensures an optimal growth environment, which is crucial for preventing mold and pest issues.
Other recent studies indicate the importance of light intensity and spectrum on plant health, and LEDs offer adjustable wavelengths to cater to different growth phases, from vegetative to flowering stages.
A 2024 study from researchers at the Chinese Academy of Agricultural Sciences identified a pivotal gene, CsMIKC1, that regulates the number of flowering sites in Cannabis sativa. This finding could significantly enhance both medicinal and grain yields in cannabis cultivation according to the study, which was published in Horticulture Research.
Cannabis sativa is highly valued for its cannabinoids, primarily produced in female flowers. However, the genetic mechanisms overseeing flower development have remained largely unexplored, hindering efforts to optimize yields.
As demand for cannabis-derived products continues to grow, understanding these regulatory mechanisms becomes crucial. Current cultivation practices often struggle due to this knowledge gap, making detailed genetic research essential for meeting increased global demand.
The study showed how CsMIKC1 drives inflorescence development, offering new strategies to boost productivity in the industry. Using CRISPR-Cas9 gene editing, the researchers explored how CsMIKC1 mutations and over-expression affect flower and grain production. The findings provide insights into the genetic basis of inflorescence growth, emphasizing the gene’s potential for enhancing crop yields and guiding future genetic improvements.
The discovery of CsMIKC1 as a target for genetic engineering could transform cannabis cultivation in greenhouses, enabling the development of novel cultivars with improved yields, according to the study’s authors. By leveraging this genetic insight, the industry may improve efficiency and scalability to meet the rising global demand for both medicinal and industrial products.
PEST MANAGEMENT
Root and soil treatments should be part of a broader IPM strategy that includes biological controls, environmental management and selection of cultivars more unfavorable to pest levels. The holistic approach can help manage pest populations more effectively and sustainably.
Recent research at Niagara College’s Horticultural & Environmental Sciences Innovation Centre (HESIC), led by Scott Golem and faculty research lead Sebastian Jacob, focuses on the challenges posed by cannabis aphids (Phorodon cannabis) and rice root aphids to cannabis crops. These pests significantly affect plant health and, consequently, the profitability of cannabis growers.
Cannabis aphids and rice root aphids compromise key growth parameters such as plant vigor, photosynthetic rates and overall height. Notably, winged aphids create quality concerns when they contaminate the final product. While one study indicated that cannabis aphids have minimal impact on THC concentration in certain cultivars, other research highlights their damaging effects on dry mass and cannabinoid profiles suggesting that the consequences of infestations can vary across cannabis strains and environments.
Since legalization, the industry has adopted advanced management strategies. These include starting with pest-free plants, quarantining new stock and using cultural practices such as heat treatment during sanitation. Additionally, biopesticides have emerged as vital tools, complemented by the introduction of Hop-Latent Viroid (HLVd) free tissue culture materials, significantly improving pest control.
Efforts to tackle rice root aphids have progressed through preventive measures and the use of biopesticide drenches. Beneficial fungi are becoming integral to managing these pests, as their presence in root zones helps reduce aphid populations. Despite these advances, challenges remain, particularly as infestations spread in both cannabis and hemp production across Canada and the U.S.
The research team is focusing on innovative pest management practices, especially given the limited options for controlling these pests. They emphasize evaluating the phytotoxicity of various management products while striving for high efficacy with fewer applications. Recent findings show some new biopesticides achieving over 90% efficacy against rice root aphids across different plant stages; however, some of these products present risks of phytotoxicity, underscoring the need for a delicate balance in pest management strategies.
Ongoing research at HESIC aims to develop effective solutions for managing cannabis aphids and rice root aphids, providing essential guidance to the industry.
POWER OF RETIPPING
A recent study from the University of Connecticut introduced a cannabis propagation method that could revolutionize cultivation practices. The method, called “retipping,” has shown to be as effective as traditional propagation techniques while significantly requiring less space. Originally published in HortScience in 2023, the research highlights the potential for enhanced productivity in cannabis cultivation.
Led by Jessica Lubell-Brand, a professor of horticulture at UConn’s College of Agriculture, Health and Natural Resources, the study involved taking cuttings from vigorous, disease-free “mother” plants that were micropropagated in controlled laboratory environments.
The study noted how retipping has the potential to produce nine times as many plants in a similar amount of floor space as stem cuttings from traditional stock mother plants, an approach that could enable growers to maximize output and quality in limited cultivation environments.
For the study, the research team compared three propagation methods: microcuttings, traditional stem cuttings and retip cuttings. All three methods resulted in plants of comparable size and chemical composition, producing cannabis flowers of equal quality. However, retipping stood out as the most space-efficient, allowing cultivators to produce a higher number of starter plants without expanding their greenhouse facilities.
Traditional cannabis cultivation relies heavily on large mother plants from which stem cuttings are harvested. These conventional plants take up substantial space, often accumulate diseases and can lose vigor over time. In contrast, the micropropagated stock plants used in this study are grown in sterile lab conditions, ensuring specimens are disease-free and vigorous, while occupying a fraction of the footprint of traditional mother plants.
By employing the retipping technique, cultivators can utilize these micropropagated plants effectively, making use of their acclimated cuttings to enhance overall output.
The research team emphasized that much remains to learn about effective cultivation practices.
