News: New Research Highlights Effects of Osmotic Stress on Cannabis Size and Flower Yield.
- Manuel Basegla
- Nov 21
- 2 min read
Published 8AM EST, Fri Nov 21, 2025 How could precision water stress (“crop steering”) affect the size of cannabis crops and quality along with the flower yield in different cultivars? Researchers in a recently published study tested precision water stress through osmotic stress treatments on two different Cannabis sativa cultivars to examine the effect on plant height and flower yield.
A new study has examined how precision water stress, or osmotic “crop steering,” impacts the growth and productivity of medical cannabis. Researchers tested two popular cultivars, Trump and Cherry, grown under three salinity levels to determine whether elevated electrical conductivity (EC) in irrigation could limit plant height without reducing flower output. Grown in controlled indoor conditions over eight weeks, the plants were evaluated for height, biomass distribution, harvest index, and cannabinoid concentrations.
The findings showed that both high and hybrid salinity treatments successfully reduced plant height by about 15%, demonstrating that osmotic stress is effective for managing vegetative growth. However, flower yield also declined in most situations. Cherry plants saw a 20% reduction in yield under both stress treatments, while Trump experienced a significant decrease only under the hybrid approach. Despite reduced yields, harvest index increased, indicating a shift toward a greater proportion of total biomass going to flowers rather than stems or leaves.
Chemical composition remained stable, with no meaningful differences in THC, CBD, THC/CBD ratios, or nutrient content between treatments. This suggests that decreased growth was driven by osmotic stress rather than nutrient deficiency and that cannabinoid quality was largely unaffected. The authors concluded that while cannabis shows strong tolerance to salinity, optimizing the timing of stress will be essential to maintain shorter plants without compromising yield.
The results highlight both the promise and challenge of crop steering. Indoor cultivators seek techniques to control plant height for improved canopy management, equipment efficiency, and space utilization, but the study shows yield losses are likely unless stress strategies are precisely calibrated. The findings point to a growing need for evidence-based cultivation protocols and potential breeding programs aimed at improving salinity tolerance, particularly for producers seeking to balance crop uniformity with maximum flower output.
Source: Cannabis Science and Technology
