@article{james_vann_suchoff_mcginnis_whipker_edmisten_gatiboni_2023, title={Hemp yield and cannabinoid concentrations under variable nitrogen and potassium fertilizer rates}, volume={4}, ISSN={["1435-0653"]}, url={https://doi.org/10.1002/csc2.20966}, DOI={10.1002/csc2.20966}, abstractNote={Abstract With the passing of the 2014 US farm bill, there is more interest in industrial hemp ( Cannabis sativa L. < 0.3% total tetrahydrocannabinol [THC]) grown for cannabinoid production. However, production recommendations that outline fertilizer requirements of cannabidiol (CBD) hemp do not exist. Our primary objective was to identify nitrogen (N) and potassium (K) fertilizer rates for maximizing biomass and CBD yield. A secondary objective was to identify the relationships between N and K rates and total THC and total CBD concentrations. Fertilizer rates from 0 to 224 kg N and 0 to 185 kg K ha −1 were tested separately at four general locations in North Carolina. Two locations were used in 2019 and 2020, while the other two were used only in 2020. Dry weight yield was predicted to increase linearly from 1822 to 3384 kg biomass ha −1 as N rate increased from 0 to 86.8 kg ha −1 . Nitrogen rates above 86.8 kg ha −1 were not predicted to increase biomass. Likewise, as N rate increased from 0 to 84.2 kg N ha −1 , CBD yield was predicted to increase linearly from 204 to 389 kg CBD ha −1 . Additional N was not predicted to increase CBD yield. The CBD and THC concentrations showed a slight bell‐shaped response curve over increasing N rates, ranging from 11.33% to 12.11% and 0.473% to 0.509%, respectively. Potassium application did not affect yield nor CBD and THC concentrations. Results from this work indicate that N is a more limiting factor than K for maximizing CBD hemp biomass production.}, journal={CROP SCIENCE}, author={James, Maggie S. and Vann, Matthew C. and Suchoff, David H. and McGinnis, Michelle and Whipker, Brian E. and Edmisten, Keith L. and Gatiboni, Luciano C.}, year={2023}, month={Apr} }
 @article{kulesza_manning_vann_suchoff_woodley_mcginnis_2022, title={Organic nitrogen fertilizer sources for field production of flue-cured tobacco (Nicotiana tabacum L.)}, volume={2}, ISSN={["1435-0645"]}, url={https://doi.org/10.1002/agj2.20989}, DOI={10.1002/agj2.20989}, abstractNote={Abstract Despite rapid expansion of organic tobacco ( Nicotiana tabacum L.) production in the US, limited research has been conducted comparing the numerous organic fertilizer sources. Organic flue‐cured tobacco traditionally relies on feather meal as the organic N fertility source, as it is readily available, but there is limited information on alternative organic N fertilizers. The objective of this research was to investigate seven different organic fertilizer sources to determine their effect on the growth and development of flue‐cured tobacco. From 2018 to 2019, field sites were established at four locations in North Carolina. Fertilizer treatments included sodium nitrate, composted layer manure, feather meal, corn gluten, soy protein, blood meal, and seabird guano. Both years, these organic N treatments were banded at sidedress (10 d after transplanting) at a rate of 78 kg total N ha −1 . Sodium nitrate resulted in higher foliar nitrate‐N concentration than composted layer manure at layby and higher cured leaf yield compared with feather meal and composted layer manure. However, soy protein and seabird guano were often similar to sodium nitrate in yield response and resulted in higher yields when compared with other sources of organic N, such as feather meal and composted layer manure. While feather meal and composted layer manure resulted in a 10 and 11% reduction in yield, respectively, there was no significant difference in tobacco value among treatments. Our results suggest that organic tobacco farmers have other options for N selection beyond the current feather meal standard.}, journal={AGRONOMY JOURNAL}, publisher={Wiley}, author={Kulesza, Stephanie B. and Manning, Nicholas J. and Vann, Matthew C. and Suchoff, David H. and Woodley, Alexander L. and McGinnis, Michelle M.}, year={2022}, month={Feb} }
 @article{mason_vann_fisher_mcginnis_2018, title={Late-Season Nitrogen Application to Tobacco Produced in Fine-Textured Soils}, volume={4}, ISSN={["2374-3832"]}, DOI={10.2134/cftm2018.02.0007}, abstractNote={Core Ideas Nitrogen is key to maximum leaf yield and quality. Nitrogen management is currently based upon expected conditions. Alternative strategies could improve N management. Alternative strategies are not suitable for fine‐textured soil types. Late‐season nitrogen (N) assimilation can greatly impact the yield and quality of flue‐cured tobacco, particularly in the fine‐textured Piedmont soils of North Carolina. Research was conducted in 2015 to 2016 to evaluate the effects of N application rate and number of N applications to the yield, quality, value, and leaf chemistry of flue‐cured tobacco. Liquid N (28% urea ammonium nitrate) was applied at 50, 70, and 90 lb N/acre. Each rate was either applied in two splits (0.5 rate 7–10 days after transplanting and 0.5 rate at layby) or three (0.5 rate 7–10 days after transplanting, a 0.25 rate at layby, and a 0.25 rate 2 weeks after layby) after transplanting. Cured leaf N concentration was similar at 50 and 70 lb N/acre (2.58 and 2.61%, respectively) but was increased in treatments receiving 90 lb N/acre (2.77%). Additionally, three N applications (2.73%) increased cured leaf N relative to two N applications (2.58%). The same treatment parameters did not impact yield or value but reduced cured leaf quality in one growing environment due to prolonged N assimilation. Results indicate that current recommendations for N application rates (50 lb/acre) and timings (split‐applied twice in equal portions) are adequate to obtain maximum yield, quality, and value on fine‐textured soils similar to those evaluated in this study.}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, publisher={American Society of Agronomy}, author={Mason, J. Hunter and Vann, Matthew C. and Fisher, Loren R. and McGinnis, Michelle S.}, year={2018}, month={Jul} }