PSIS in cannabis cultivation: how plant stem infusion of sucrose boosts flower yield and cannabinoid production

Published on: 26/01/2026

Why researchers are looking for “non-standard” yield levers

Cannabis sativa L. has gained economic and medical relevance, and the demand for consistent, high-quality plant material has increased in both medicinal and recreational markets (such as, for example, CBD oil Sativa). In this context, cultivation research often targets two outcomes that are conceptually related yet technically distinct: yield of inflorescences (the harvested CBD flower biomass) and yield of secondary metabolites, particularly cannabinoids.

The study presented here starts from a pragmatic problem. Traditional nutrient delivery methods—drenching, fertigation, foliar feeding, even when paired with plant-growth-promoting rhizobacteria—may face limitations related to absorption and distribution within the plant. That limitation has encouraged experimentation with alternative delivery routes that bypass some of the constraints of roots and leaves.

One such route is plant stem infusion (PSI), a technique explored in other plant species to deliver nutrients and various compounds directly into the stem. The study at the center of this article extends that concept to cannabis and tests a specific variant: plant stem infusion of sucrose (PSIS).

Before we begin, it is worth remembering that this article by Justbob is written for informational and educational purposes only. It discusses a scientific study conducted in a controlled research setting and does not constitute advice, instructions, or encouragement to cultivate cannabis. Laws and regulations on cannabis cultivation, possession, processing, and research vary widely across countries and, in some jurisdictions, across regions within the same country.

Any real-world decision involving cannabis must be assessed case by case and in full compliance with the laws in force where the reader lives, and any health-related decision must be taken exclusively with qualified healthcare professionals.

With that caution clearly stated at the outset, the focus can remain where it belongs: on what the research actually tested, what it found, what it did not prove, and why the findings matter from a scientific and agronomic perspective.

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The research in question, in one sentence

The study titled “Enhancing yield of cannabis inflorescences and cannabinoids through plant stem infusion of sucrose: A novel cannabis cultivation approach” reports that, in a pilot experiment, low-pressure infusion of sucrose into cannabis stems was associated with increases in flower dry mass (up to 31%) and cannabinoid yield (up to 34%) compared to non-infused control plants, while higher infusion pressures had negative effects on morphology and cannabinoid outcomes.

That sentence captures the headline, but it does not explain the mechanism, the design choices, the limits, or the reasons for caution. Those details matter.

What PSIS means, explained without assuming expertise

Plant stem infusion refers to introducing a solution into a plant’s stem using a needle and a controlled system. The goal is to move substances into the plant’s internal transport pathways rather than relying on uptake from soil or leaf surfaces. In other contexts, similar approaches have been used as “tree injections” for disease management and pest control, and as experimental delivery routes for nutrients.

Sucrose is a central carbohydrate in plant biology. In plants, it functions as a source of carbon and energy and, crucially, as a signaling molecule that can influence physiological pathways and gene activity. Prior studies in other crops have explored sucrose infusion to enhance growth and yield. The rationale is not that sucrose is “magic,” but that changing the plant’s carbohydrate environment can alter metabolism, growth allocation, and the production of specialized metabolites.

In the cannabis study, sucrose is introduced exogenously—meaning from outside the plant—through the stem, with the hypothesis that an additional carbon source, delivered directly to transport tissues, could influence biomass partitioning and cannabinoid yield.

A key detail that must not be misunderstood: this is not about “sugar feeding” as a consumer practice

The technique described is not equivalent to consumer practices, home remedies, or ad hoc “feeding” methods. The study involved a defined experimental setup, controlled pressures, measured flow rates, and subsequent lab analyses. Translating a controlled infusion protocol into informal, uncontrolled practices would be scientifically unfounded and, depending on local law, legally problematic.

The research is best understood as a controlled investigation into plant physiology and agronomic optimization within a research context—not as a template for unsupervised replication.

Study design at a glance: what was varied, what was held constant

The experiment tested two primary variables:

1. Sucrose concentration in the infusion solution: 0%, 7.5%, 15%, 30% (w/v)
2. Applied pressure on the liquid surface: 0.5 bar, 1 bar, 2 bar

Plants were grown in a single 12 m² growth chamber at a density of six plants per m², for a total of 72 plants. There were:

• a negative control group (no infusion),
• a positive control group infused with 0% sucrose (distilled water),
• and treatment groups combining the different sucrose concentrations with the different pressures.

The plant material was one genotype of the variety Charlotte’s Angel®, described as chemotype III (high CBD cannabis, low THC, always below 1% in this study).

This last point matters for interpretation. The results concern this genotype and chemotype under the study’s chamber conditions; they should not be generalized automatically to other genotypes, other chemotypes, or field environments.

How infusion was performed, described as methodology, not a “how-to”

The infusion solution consisted of distilled water plus sucrose at the assigned concentration. The delivery system used vertical PVC tubes connected to standard tubing for IV infusion and a needle inserted into the stem at a lower node. Pressure was applied via a compressor connected to the tubes, and the system remained pressurized for the duration of the experiment.

The researchers monitored flow as a practical indicator of successful placement within a functional transport route. Injection volumes were estimated by measuring changes in the height of the solution column over time.

These details are mentioned to explain what “infusion under pressure” practically meant in the study. They are not presented as instructions and should not be treated as such.

What the researchers measured, and why each metric matters

The study assessed three broad categories:

1) Morphology and biomass allocation

Measurements included plant height, dry mass of different organs (flowers, stems, leaves, roots), and other structural traits. After harvest, plant organs were dried and weighed separately. This allowed the researchers to examine not just total mass but how biomass was distributed across plant parts.

2) Physiological parameters

Photosynthesis-related measures included net carbon assimilation, stomatal conductance, and chlorophyll content. Respiration was also measured. These metrics help interpret whether the plant’s core carbon economy and stress response are being altered by sucrose infusion and pressure.

3) Cannabinoid yield and composition

Cannabinoids were quantified using HPLC, with peaks identified through standards and final concentrations calculated using standard curves for 16 cannabinoids. Importantly, the study reports cannabinoid yield per plant, not merely concentration, which ties chemistry to biomass outcomes.

The most important results, stated precisely

Low pressure (0.5 bar) was the “beneficial” pressure regime

Across morphological analyses, the 0.5 bar group stood out. Plants treated at this pressure showed:

• a significant increase in flower and stem dry mass compared to the negative control,
• and a significant increase in height compared to control.

In contrast, higher pressures were associated with less favorable outcomes.

Flower dry mass increased by up to 31% under optimal conditions

The study’s highlights report that sucrose stem infusion at 0.5 bar increased cannabis flower dry mass by up to 31%. The emphasis on “up to” is essential: it signals variability across treatment combinations and plants, not a universal guarantee.

Cannabinoid yield increased by up to 34%, but only under specific combinations

The study reports that cannabinoid yield rose by up to 34% when using 15–30% sucrose at 0.5 bar.

More specifically, cannabinoid yield per plant was significantly higher at:

• 0.5 bar with 15% sucrose (reported as 6.00 g/plant),
• 0.5 bar with 30% sucrose (reported as 5.99 g/plant),

compared with the negative control (reported as 4.48 g/plant).

A meaningful nuance appears here: at 0.5 bar, cannabinoid yield per plant increased with higher sucrose concentration, while this pattern did not hold at higher pressures.

Higher pressures (1–2 bar) were associated with negative effects

The highlights state that higher pressures (1–2 bar) negatively affected morphology and cannabinoid content. The results section adds that some treatments at 2 bar showed decreased cannabinoid yield compared with control, illustrating that pressure is not a neutral technical parameter; it is biologically consequential.

Interpreting the physiology: why respiration changed while photosynthesis did not

One of the more intriguing outcomes is that many photosynthetic parameters did not show significant differences compared to control, while respiration increased significantly under 1 bar pressure on the first measurement day (reported fold change 1.33, p < 0.01).

This pattern is consistent with a plausible metabolic story that the authors themselves suggest: under higher pressure, the plant may receive more exogenous sucrose, which can stimulate respiration as the plant processes that additional carbon input. At the same time, net carbon assimilation and stomatal conductance may remain within similar ranges—at least under the specific measurement windows and chamber conditions used.

This does not mean photosynthesis “does not matter,” and it does not prove a stable long-term physiological state. It indicates that, in this pilot study, the measured photosynthetic variables did not shift significantly in ways that would explain yield changes on their own, whereas respiration showed a pressure-linked change that may reflect metabolic adjustment or stress response.

Biomass trade-offs: flowers and stems up, leaves down

A notable morphological pattern was that leaf biomass was reduced across all treated groups, even though the differences were not statistically significant. At the same time, flowers and stems tended to show higher dry mass, especially at 0.5 bar.

This suggests the possibility of a reallocation of biomass—an altered “investment strategy” by the plant—where carbon and resources are distributed differently among organs. In agronomic terms, the most consequential part of that reallocation, from a harvest perspective, is the increase in flower dry mass under the optimal regime.

Yet this should be read as an observed pattern under experimental conditions, not as a universal rule. The study itself is careful to frame its findings as promising and in need of further optimization.

Cannabinoid profile: what changed, what stayed stable

The study reports that CBDA was the cannabinoid with the highest concentration (10.72% to 12.42%) and that there was no statistical difference between treatments for CBDA concentration. It also notes that total THC concentration ranged narrowly in this low-THC chemotype, with the lowest reported in control plants (0.36%) and the highest reported at 0.5 bar and 7.5% sucrose (0.43%).

Two points deserve careful handling:

1. These values relate to this specific genotype and chemotype grown under the described chamber conditions.
2. The study’s headline outcomes emphasize cannabinoid yield per plant, which depends on both biomass and concentration. Increases in yield can occur even if concentrations remain broadly similar, provided flower mass increases.

Why pressure appears to be the critical “control knob”

The study reports that system pressure had the most significant impact on the total injected volume, with higher pressures resulting in greater injected volumes. Distilled water infused more readily than sucrose solutions due to lower viscosity.

This offers a mechanistic bridge between engineering and biology. Pressure affects how much solution enters the plant, and solution properties (viscosity, osmotic pressure) affect resistance to flow. Too little delivery might yield no effect; too much, delivered too aggressively, might induce stress, alter morphology in undesirable ways, or disrupt the metabolic balance that supports cannabinoid production.

The study’s central empirical claim can be expressed in a disciplined way: there appears to be an “optimal zone” where delivery is sufficient to influence yield positively without triggering the negative consequences associated with higher pressures.

What makes this study “novel,” and why novelty is not the same as validation

The authors present this as the first study, to their knowledge, applying sucrose stem infusion in cannabis. That novelty is scientifically meaningful because it introduces a new experimental angle and a new set of questions.

At the same time, novelty should not be mistaken for readiness, scalability, or general applicability. The study is explicitly described as a pilot. Pilot studies are valuable because they map possibilities and help decide what deserves larger, more expensive investigations. They are not definitive endpoints.

Practical and ethical boundaries: why translation to real-world contexts is non-trivial

The discussion section notes that stem infusion has not achieved broad commercial adoption in other crops, likely due to cost and scalability constraints. The authors suggest that cannabis could be a special case because it is a high-value crop per gram of inflorescence biomass, making yield gains potentially more economically relevant.

Even if the economics were favorable, real-world translation would still face hurdles that the study itself highlights:

• a need for standardized and efficient injection systems,
• labor and scalability constraints,
• contamination risks and the need for sterile procedures to prevent infections,
• and the need for broader testing across varieties, genotypes, and chemotypes.

Those hurdles are technical and biological. They are also legal and ethical, because cannabis cultivation is heavily regulated in many jurisdictions. Any discussion of “commercial viability” must be interpreted as a research and industry question within compliant frameworks, not as an invitation to attempt cultivation.

What this study does not establish, even if the results look strong

A prudent reading must state clearly what is not proven:

• It does not prove that PSIS will increase yield in all cannabis varieties.
• It does not prove that PSIS will behave similarly in different environments (greenhouse vs chamber vs outdoor).
• It does not prove long-term sustainability, plant health outcomes over repeated cycles, or downstream quality aspects beyond cannabinoid yield as measured here.
• It does not provide a consumer-safe or legally universal pathway for any action; legality and compliance remain jurisdiction-specific and non-negotiable.
• It does not justify informal replication, especially in contexts where cultivation is restricted or prohibited.

The correct scientific posture is to treat the results as a well-defined signal—strong enough to justify follow-up—while preserving the boundaries between experimental evidence and broader claims.

Why the findings matter, even for readers who will never cultivate anything

For a general audience, the value of this research is not in the operational details of cultivation. It is in what it reveals about plant biology and controlled agronomic innovation.

PSIS, as tested here, is an example of how plant metabolism can be influenced through targeted delivery of a common molecule—sucrose—combined with engineering control—pressure regulation. The results suggest that changing the plant’s carbon availability and signaling environment through stem infusion can alter biomass distribution and increase measured cannabinoid yield per plant under specific conditions.

That idea—precise control of delivery parameters to modulate yield-related outcomes—extends beyond cannabis. It reflects a broader trend in crop science: the search for interventions that can be measured, optimized, and replicated under controlled conditions, then evaluated for scalability and safety.

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Conclusion: a promising pilot result, bounded by strict interpretive discipline

The study by Zupančič and colleagues presents PSIS as a novel experimental approach in cannabis cultivation research, showing that low-pressure sucrose infusion (0.5 bar) combined with higher sucrose concentrations (15–30%) was associated with increases in flower dry mass (up to 31%) and cannabinoid yield (up to 34%) in a controlled growth-chamber pilot study using a low-THC, CBD-dominant chemotype III genotype.

Equally important, the same study reports that higher pressures (1–2 bar) had negative impacts on morphology and cannabinoid outcomes, reinforcing the idea that the technique is not a simple “more is better” intervention, but one that appears to require a narrow and carefully controlled operating window.

From a scientific standpoint, the work establishes a credible starting point for further research: larger populations, different genotypes and chemotypes, deeper investigation of mechanisms, and robust evaluation of practical constraints and safety risks. From a communication standpoint, it demands restraint: the findings are promising, but they remain bounded by experimental conditions, and they do not warrant extrapolation into unsupervised practices.

This Justbob article is provided strictly for informational and educational purposes. It does not encourage cannabis cultivation, does not provide actionable cultivation instructions, and does not promote any activity that may be illegal. Readers must always comply scrupulously with the laws and regulations in their country and consult qualified professionals for any health-related matter.

PSIS in cannabis cultivation: Takeaways

• The study clearly shows that plant stem infusion of sucrose (PSIS) is beneficial only within a narrow operational window. At 0.5 bar, plants displayed significant increases in flower dry mass and cannabinoid yield, while higher pressures (1–2 bar) produced neutral or even negative effects. From a data perspective, pressure emerges as the dominant driver shaping outcomes, reinforcing that optimization—not intensification—is what matters.
• Despite notable increases in flower and stem dry mass, most photosynthetic parameters remained statistically unchanged compared to controls. This suggests that PSIS does not boost yield by “speeding up” photosynthesis, but rather by altering how the plant allocates resources, shifting biomass away from leaves and toward economically relevant organs such as flowers.
• The observed gains—up to 31% in flower dry mass and 34% in cannabinoid yield—were obtained under controlled conditions, using a single low-THC, CBD-dominant genotype in a growth chamber. The data support PSIS as a research-grade innovation, not a universally applicable solution. Any broader relevance depends on further studies across genotypes, environments, and long-term cultivation cycles, always within legal and regulatory boundaries.

PSIS in cannabis cultivation: FAQ

What is PSIS and how was it tested in cannabis cultivation?

PSIS stands for Plant Stem Infusion of Sucrose. In the study discussed, sucrose solutions were infused directly into cannabis plant stems under controlled pressure in a growth chamber. The method was tested experimentally to evaluate its effects on plant morphology, flower dry mass, and cannabinoid yield, and was not intended as a consumer or cultivation practice.

What were the main effects of sucrose stem infusion on flower yield and cannabinoids?

The study found that low-pressure infusion (0.5 bar) combined with sucrose concentrations of 15–30% was associated with increases in flower dry mass of up to 31% and cannabinoid yield of up to 34% compared to non-infused control plants. Higher pressures, however, showed negative effects on plant morphology and cannabinoid outcomes.

Does this research mean PSIS can be applied in real-world cannabis cultivation?

The research was conducted as a pilot study in a controlled experimental setting using a single genotype and chemotype. It does not establish PSIS as a validated or universally applicable cultivation method, nor does it encourage real-world application. Any consideration of cannabis cultivation must comply strictly with local laws and regulations.