Impact of Different Phytohormones on Morphology, Yield and Cannabinoid Content of <i>Cannabis sativa</i> L

• Main Authors: Lisa Burgel, Jens Hartung, Daniele Schibano, Simone Graeff-Hönninger
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Plants
• Subjects: <i>Cannabis sativa </i>L.; growth regulators; indoor growth; plant morphology; length of axillary branches; number of internodes
• Online Access: https://www.mdpi.com/2223-7747/9/6/725

The impact of exogenously applied plant growth regulators (PGR), 1-naphthalenaecetic acid (NAA), 6-benzylaminopurine (BAP), and a mixture of both (NAA/BAP-mix), was investigated in regard to plant height, length of axillary branches, number of internodes, biomass yield and cannabinoid content of three different phytocannabinoid-rich (PCR) <i>Cannabis </i>genotypes. The results showed that total plant height was significantly reduced under the application of NAA (28%), BAP (18%), and NAA/BAP-mix treated plants (15%). Axillary branch length was also significantly reduced by 58% (NAA) and 30% (NAA/BAP-mix). BAP did not significantly reduce the length of axillary branches. The number of internodes was reduced by NAA (19%), BAP (10%), and the NAA/BAP-mix (14%) compared to the untreated control. NAA application influenced the plant architecture of the tested cv. KANADA beneficially, resulting in a more compact growth habitus, while inflorescence yield (23.51 g plant⁻¹) remained similar compared to the control (24.31 g plant⁻¹). Inflorescence yield of v. 0.2x and cv. FED was reduced due to PGR application while cannabinoid content remained stable. Overall, the application of PGR could be used on a genotype-specific level to beneficially influence plant architecture and optimize inflorescence yield per unit area and thus cannabinoid yield, especially in the presence of space limitations under indoor cultivation.