Researchers from the University of Ljubljana have tested a novel method to increase cannabis yield and cannabinoid production: plant stem infusion of sucrose (PSIS). The pilot study is the first of its kind in cannabis and shows that carefully controlled infusion at low pressure can improve flower mass and cannabinoid yield.
Plant stem infusion is certainly not new in the world of growing crops. But researchers wanted to see what the effect of that would be for cannabis.
Seventy-two plants of Charlotte's Angel® (a high-CBD, low-THC chemotype III variety) were divided into groups receiving different sucrose concentrations: 0%, 7.5%, 15%, and 30%. Plants were subjected to infusion pressures of 0.5, 1, and 2 bar. Controls included plants with no infusion and plants infused with water only.
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The results showed that infusion at low pressure, particularly 0.5 bar, significantly improved plant height, flower dry mass, and stem mass compared with controls. At this pressure and at the higher sucrose concentrations of 15 to 30 percent, flower dry mass rose by up to 31 percent, while cannabinoid yield increased by as much as 34 percent. At the same time, leaf biomass consistently decreased in all infused plants compared with controls, suggesting that resources were redirected from leaf growth toward flowers. However, they found that infusion pressure of 2 bar would be detrimental to the plant, to the point of even negatively affecting its morphology.
On the other hand, parameters such as photosynthesis, chlorophyll content, and stomatal conductance did not show significant differences between treated and control plants. The only notable change was an increase in respiration at 1 bar, which the authors suggest may reflect a metabolic response to excess sucrose. While CBDA remained the most abundant cannabinoid, between 10.7 and 12.4 percent, THC levels stayed below 1 percent across all groups, which is consistent with the cultivar's profile.
According to the researchers, PSIS at low pressure and with higher sucrose concentrations "represents a promising innovation in cannabis cultivation." It's anyway necessary to do more research, as researchers themselves stress.
Source: Science Direct
