Industrial hemp vegetative growth affected by substrate composition

J.T. Smith, B.E. Jackson, B.E. Whipker, W.C. Fonteno
Little scientific literature exists on cultivation techniques for cannabis (Cannabis sativa L.) in container production environments, and there is almost none concerning horticultural substrate requirements. Substrates are one of the most important factors in maximizing crop production in controlled environments and the efficient use of inputs such as water and fertilizer. Due to the growing economic importance of hemp in the United States, and the need for a more thorough understanding of its cultivation in container culture, two studies were conducted to evaluate vegetative growth in a variety of horticultural substrates. Four cultivars, ‘Cherrywine’, ‘Baox’, ‘T1’, and ‘Sweetened’ were grown in peat-based and coir-based mixes containing either 0, 15, 30, or 45% perlite by volume. Six weeks after transplant, height, diameter, growth index and dry weight were measured. Additionally, to evaluate a range of commercially available mixes, ‘Cherrywine’, and ‘Baox’ were grown in 20 mixes marketed to the cannabis industry. These plants were harvested and dry weights measured at four weeks after transplant. Aside from coir-based mixes with higher levels of perlite, growth measurements were similar in all substrates tested. Physical properties of all 28 mixes were determined using the NCSU Porometer method, and all were found to be within or close to recommended ranges for most horticultural crops. These experiments suggest cannabis can be grown successfully in a range of horticultural substrates.
Smith, J.T., Jackson, B.E., Whipker, B.E. and Fonteno, W.C. (2021). Industrial hemp vegetative growth affected by substrate composition. Acta Hortic. 1305, 83-90
DOI: 10.17660/ActaHortic.2021.1305.12
Cannabis sativa L., growing media, physical properties, vegetative growth, perlite

Acta Horticulturae