Vee
Ancient Member
Abstract: Many abiotic factors, such as mineral nutrients—including phosphorus (P)—fertility, can
impact the yield and growth of Cannabis sativa. Given the economic portion of C. sativa is the
inflorescence, the restriction of P fertility could impact floral development and quality could be
detrimental. This study sought to track the impacts of varying P concentrations (3.75, 7.50, 11.25, 15.0,
22.50, and 30.0 mg · L −1 ) utilizing a modified Hoagland’s solution. This experiment examined plant
height, diameter, leaf tissue mineral nutrient concentrations, and final fresh flower bud weight as well
as floral quality metrics, such as cannabinoids and terpenes. The results demonstrated that during
different life stages (vegetative, pre-flowering, flowering), P concentrations impact C. sativa growth
and development and yield. Regarding the cannabinoid pools, results varied for the individual
cannabinoid types. For the acid pools, increasing fertility concentrations above 11.25 mg · L −1 P did
not result in any increase in cannabinoid concentrations. These results indicate that, if a crop is
being produced under greenhouse conditions, specifically for cannabinoid production, an excessive P
supply did not result in higher cannabinoid production. However, plants grown with a higher rate of
P fertility (30.0 mg·L −1 ) had greater plant width and may result in more buds per plant.
blah-blah 5. Conclusions
These results indicate that C. sativa has different fertility requirements based on the life stage and
the end goal of production. For example, if a grower is producing mother stock plants for vegetatively
propagated cuttings, plants will remain vegetative throughout their lifecycle. Thus, a concentration of
11.25 mg·L −1 P or greater may be adequate for this operation.
If C. sativa plants are to be grown for the florescence and/or cannabinoids or terpenes either for
the fresh flower market or a distillate market, a P concentration above 11.25 mg · L −1 is preferred. While
a P concentration of 22.5 mg · L −1 resulted in the greatest bud fresh weight when compared to the
lowest two concentrations, it did not result in any greater increase in the active or acid cannabinoid
pools. Additionally, higher P rates above 22.5 mg · L −1 did result in greater lateral production and
consequently more nodes to produce the economic portion (floral material). Thus, a follow-up
study should be completed to see if the increase in lateral nodes and floral material would result
in a greater whole plant yield in floral material, despite the higher concentration of P resources not
resulting in greater cannabinoid production in said flowers. Thus, for production in a cannabinoid
or distillate market, a P fertility concentration of 11.25 mg · L −1 would be adequate, while for fresh
market production, a P fertility concentration may be greater (22.5 mg · L −1 ) to account for more visually
appealing floral material.
Additionally, these results indicate that the luxury consumption level for C. sativa regarding plant
growth metrics and leaf tissue accumulation was not reached, given that no leveling off or plateauing
of leaf tissue P was observed. This may indicate that C. sativa requires higher levels of P fertility
to reach the uppermost limit of resource accumulation in the leaf tissue. Higher levels of P fertility
concentrations should be explored to elucidate the uppermost levels of P resources the plant can
acquire in the leaf tissue. Additional screening should be completed with other cultivars to quantify
different P fertility needs more accurately for other types of C. sativa, given that a wide variety of
plant architectures exists within C. sativa (Figure 5). Furthermore, the sampling of different plant parts
(petioles, stems, roots etc.) for mineral nutrient concentration overtime would help illuminate the
accumulation and reallocation of mineral resources within C. sativa over its life stages
HERE:
impact the yield and growth of Cannabis sativa. Given the economic portion of C. sativa is the
inflorescence, the restriction of P fertility could impact floral development and quality could be
detrimental. This study sought to track the impacts of varying P concentrations (3.75, 7.50, 11.25, 15.0,
22.50, and 30.0 mg · L −1 ) utilizing a modified Hoagland’s solution. This experiment examined plant
height, diameter, leaf tissue mineral nutrient concentrations, and final fresh flower bud weight as well
as floral quality metrics, such as cannabinoids and terpenes. The results demonstrated that during
different life stages (vegetative, pre-flowering, flowering), P concentrations impact C. sativa growth
and development and yield. Regarding the cannabinoid pools, results varied for the individual
cannabinoid types. For the acid pools, increasing fertility concentrations above 11.25 mg · L −1 P did
not result in any increase in cannabinoid concentrations. These results indicate that, if a crop is
being produced under greenhouse conditions, specifically for cannabinoid production, an excessive P
supply did not result in higher cannabinoid production. However, plants grown with a higher rate of
P fertility (30.0 mg·L −1 ) had greater plant width and may result in more buds per plant.
blah-blah 5. Conclusions
These results indicate that C. sativa has different fertility requirements based on the life stage and
the end goal of production. For example, if a grower is producing mother stock plants for vegetatively
propagated cuttings, plants will remain vegetative throughout their lifecycle. Thus, a concentration of
11.25 mg·L −1 P or greater may be adequate for this operation.
If C. sativa plants are to be grown for the florescence and/or cannabinoids or terpenes either for
the fresh flower market or a distillate market, a P concentration above 11.25 mg · L −1 is preferred. While
a P concentration of 22.5 mg · L −1 resulted in the greatest bud fresh weight when compared to the
lowest two concentrations, it did not result in any greater increase in the active or acid cannabinoid
pools. Additionally, higher P rates above 22.5 mg · L −1 did result in greater lateral production and
consequently more nodes to produce the economic portion (floral material). Thus, a follow-up
study should be completed to see if the increase in lateral nodes and floral material would result
in a greater whole plant yield in floral material, despite the higher concentration of P resources not
resulting in greater cannabinoid production in said flowers. Thus, for production in a cannabinoid
or distillate market, a P fertility concentration of 11.25 mg · L −1 would be adequate, while for fresh
market production, a P fertility concentration may be greater (22.5 mg · L −1 ) to account for more visually
appealing floral material.
Additionally, these results indicate that the luxury consumption level for C. sativa regarding plant
growth metrics and leaf tissue accumulation was not reached, given that no leveling off or plateauing
of leaf tissue P was observed. This may indicate that C. sativa requires higher levels of P fertility
to reach the uppermost limit of resource accumulation in the leaf tissue. Higher levels of P fertility
concentrations should be explored to elucidate the uppermost levels of P resources the plant can
acquire in the leaf tissue. Additional screening should be completed with other cultivars to quantify
different P fertility needs more accurately for other types of C. sativa, given that a wide variety of
plant architectures exists within C. sativa (Figure 5). Furthermore, the sampling of different plant parts
(petioles, stems, roots etc.) for mineral nutrient concentration overtime would help illuminate the
accumulation and reallocation of mineral resources within C. sativa over its life stages
HERE:
