Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes

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.

Effect of Colonization of Trichoderma harzianum on Growth Development and CBD Content of Hemp (Cannabis sativa L.)

“…This hypothesis is underpinned by the well-known production of multiple volatile organic compounds by Trichoderma species that promote the plant growth of plants [ 77 ] and the secretion of small molecules, such as polyketides, observed in Trichoderma harzianum T-22 [ 78 ]. Moreover, a second indirect pathway that might be beneficial for CBD content increase is the enhancement of phosphorus availability [ 79 ]. Trichoderma strains phosphate solubilization activity has been previously reported [ 80 ].…”

Sustainable Cannabis Nutrition: Elevated root-zone phosphorus significantly increases leachate P and does not improve yield or quality

“… Shiponi and Bernstein (2021a) found that 30 mg P per L was necessary for maximum dry mass after four weeks of vegetative growth in two high-THC Cannabis cultivars. In contrast, Cockson et al. (2020) found no increase in dry weight above 11 mg per L after eight weeks of vegetative growth in a high-CBD cultivar, despite P concentration in leaves nearly doubling as the P input increased from 11 to 30 mg per L.…”

“…Recent studies indicate that P in continuous liquid feed is adequate at about 15 mg per L for vegetative growth in greenhouse conditions with ambient CO 2 (Cockson et al, 2020;Veazie et al, 2021), but many studies, including this one, indicate higher levels of P are necessary for optimal reproductive growth (Bevan et al, 2021;Shiponi and FIGURE 3 Cumulative leached P over eight weeks of reproductive growth at input P of 25, 50 and 75 mg per L. Each point represents the total leached P of a leachate collection tray that contained three separate containers. Time series of P in the leachate at an input P of 25, 50 and 75 mg per L. Each line represents a sample taken from a leachate collection tray that contained three separate containers.…”

“…In a comprehensive study with Cannabis , ( Bernstein et al., 2019 ) found that supplementing constant liquid fertilization of 17 mg P per L with additional P from 2 g of superphosphate ([Ca(H 2 PO 4 ) 2 ]; 0.5 g P) per pot at three-week intervals did not increase flower yield or the concentration of three major cannabinoids (CBD, CBG, and CBN) in flowers compared to the control. Cockson et al. (2020) reported a significant increase in total above ground biomass up to 23 mg per L, but there was no increase in flower yield above 11 mg per L. Cannabinoid concentration was higher under P-deficient conditions, but there was no effect of P on cannabinoids above 11 mg per L ( Cockson et al., 2020 ).…”

Enhancement of growth and Cannabinoids content of hemp (Cannabis sativa) using arbuscular mycorrhizal fungi

“…Our results support that finding as plants that were fertilized with NPK outperformed unfertilized control plants in the amount of biomass produced, while at the same time exhibiting slightly higher N concentrations. It has been observed that the production of cannabinoids is limited by phosphorus ( Cockson et al, 2020 ) and that almost all of P acquired is found in inflorescences ( Shiponi and Bernstein, 2021 ). These latter authors also observed a negative correlation between floret yield and cannabinoid concentration and suggested, in line with Imo (2012) , that dilution was responsible for that negative concentration.…”