Page 15 - CSHS 2022 Book of Abstracts - 2022-08-22 web version

CSHS 2022 Conference

(CO.5) How to Diagnose Nutrient Deficiencies and Use the Right Nutrient Recipes for Cannabis
Cultivation
Youbin Zheng , David Llewellyn , Scott Golem , Max Jones
3
1*
2
1
1. Department of Environmental Sciences, University of Guelph, Guelph, ON; 2. HEXO Corp., Gatineau, QC; 3. Department
of Plant Agriculture, University of Guelph, Guelph, ON
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Two cannabis nutrition experiments were conducted in a commercial cannabis cultivation facility. In the first trial,
cannabis plants were grown in solution culture under short photoperiod conditions (i.e., flowering stage) with
either a complete nutrient solution or nutrient solution treatments missing one each of the following elements:
nitrogen, phosphorus, potassium, sulphur, calcium, magnesium, iron, and manganese. Plant performance, especially
the development of nutrient deficiency symptoms, were observed and photographed from the start of the flowering
phase to inflorescence maturity. In the second trial, cannabis plants were grown in nutrient solutions with different
ratios of nitrogen, phosphorous and potassium (i.e., NPK) and plant performance, especially inflorescence yield and
potency were measured. Based on the collected results, this presentation will discuss how to diagnose nutrient
deficiencies and what nutrient recipes to use in cannabis cultivation.

(CO.6) Improving biological control strategies for the management of cannabis aphid
Jason Lemay*, Cynthia Scott-Dupree
School of Environmental Science, University of Guelph, Guelph, ON
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Like most other crops, cannabis cultivation is challenged by a variety of insect and mite pests. In fact, two pests,
cannabis aphid (Phorodon cannabis) and hemp russet mite (Aculops cannabicola) are cannabis specialists, not
known to feed or reproduce on any other plant. Very little is known of their biology, and cannabis aphid has been a
challenge for cannabis growers to manage. While biological control has been widely adopted by the cannabis
industry, it has failed to provide the benefits often found in other crops. I will present the results of ongoing research
into identifying parasitoids that can effectively manage cannabis aphid in controlled environment settings.
Additionally, I will discuss some of the factors that make cannabis a particularly difficult crop for biological control,
including plant characteristics, production methods, and important knowledge gaps that must be filled to develop
effective biological control solutions for this crop. Due to the novelty of this crop, there are significant opportunities
for interdisciplinary research focused on optimizing both crop production and crop protection.

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