Hemp production in New Mexico – Ongoing trials and future outlooks

Production of hemp (Cannabis sativa L.) in New Mexico has been primarily dominated by high-cannabinoid crops since the state’s legalization in 2018. A major priority for NM hemp growers is identification of high-cannabinoid varieties that provide uniform, high-yielding crops while remaining below the federal tetrahydrocannabinol (THC) threshold. Year 1 (2021) data from a three-location, high-CBD variety trial provided several insights into variety performance and the influence of planting date. The varieties ‘Wife’ and ‘Sweetened’ were grown at the New Mexico State University (NMSU) Sustainable Agriculture Science Center at Alcalde (36.09°N), the NMSU Agricultural Science Center at Los Lunas (34.77°N), and NMSU Leyendecker Plant Science Center (32.20°N). Administrative and logistical challenges delayed planting dates: Leyendecker on May 25, Los Lunas on June 15, and Alcalde on July 15. This caused a significant difference in the amount of biomass produced per plant at each location. The earliest planting produced 2.7x more biomass for ‘Sweetened’ and 1.7x more biomass for ‘Wife’ than the latest planting. In general, ‘Sweetened’ produced more biomass than ‘Wife’ at each location; the yield difference decreased with the later plantings at the higher latitudes. This could be due to differing rates of biomass accumulation in each variety or the better suitability of a variety for each latitude. Both varieties were harvested when the apical floral structures were near or at the 0.3% total THC limit. The official state compliance sampling incorporates floral and leaf material from different sections of the plant, which yielded all compliant THC levels. This highlights the important of implementing consistent sampling protocols. Year 2 (2022) trials are currently underway at the same three locations, with the same two high-cannabinoid varieties (with the inclusion of additional fiber and grain varieties, and replicated plots of treatments). The current state of the hemp industry in New Mexico has led farmers to reconsider planting/management strategies and the value-added potential of the fiber remaining from high-cannabinoid crops. Across all varieties and locations in the Year 1 trial, between 30-51% of the total crop yield was fiber residue that cannot be extracted for cannabinoids. This represents a sizable amount of lignocellulosic material that the majority of hemp farmers treat as waste. Approaching hemp production from a dual-purpose cropping system may create additional avenues for producers growing hemp at low latitudes to combat losses and maximize potential of their crop.