Tillage system and seeding rate effects on the performance of Brassica carinata

Authors: IBOYI, JOSEPH - University Of Florida; MULVANEY, MICHAEL - University Of Florida; Balkcom, Kipling; SEEPAUL, RAMDEO - University Of Florida; BASHYAL, MAHESH - University Of Florida; PERONDI, DANIEL - University Of Florida; LEON, RAMON - North Carolina State University; DEVKOTA, PRATAP - University Of Florida; SMALL, IAN - University Of Florida; GEORGE, SHEEJA - University Of Florida; WRIGHT, DAVID - University Of Florida

Submitted to: Global Change Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2021
Publication Date: 1/27/2021
Citation: Iboyi, J.E., Mulvaney, M.J., Balkcom, K.S., Seepaul, R., Bashyal, M., Perondi, D., Leon, R.G., Devkota, P., Small, I.M., George, S., Wright, D.L. 2021. Tillage system and seeding rate effects on the performance of Brassica carinata. Global Change Biology. 13:600-617. https://doi.org/10.1111/gcbb.12809.
DOI: https://doi.org/10.1111/gcbb.12809

Interpretive Summary: Brassica carinata, a non-food oilseed crop, is used to produce renewable fuels because of its high oil content and favorable fatty acid profile. Production in the southeastern United States is relatively new, and information on agronomic management practices to optimize growth and yield is limited. Since optimal seeding rate may depend on the land preparation method for this small-seeded crop, scientists at the Univ. of Florida, North Carolina State Univ. and USDA-ARS (Auburn, AL) evaluated the effect of tillage system (conventional, no-till, broadcast-disc, and ripper-roller) and seeding rate (1.12, 5.60, 10.09 and 14.57 kg seed ha-1) on the performance of B. carinata. Yield response to tillage system was variable. Among seeding rate treatments, yield was lowest at 1.12 kg seed ha-1 and similar among 5.60, 10.09, and 14.57 kg seed ha-1 at all site-years. Results indicate that among seeding rates treatments used, 5.6 kg seed ha-1 rate was optimal at all site-years regardless of land preparation method and is thus the recommended seeding rate for commercial carinata production in the Southeastern United States. This general agronomic production information will benefit growers interested in adopting carinata into southeastern US crop production systems.

Technical Abstract: Brassica carinata, a non-food oilseed crop, is used to produce renewable fuels because of its high oil content and favorable fatty acid profile. Production in the southeastern United States is relatively new, and information on agronomic management practices to optimize growth and yield is limited. Since optimal seeding rate may depend on the land preparation method for this small-seeded crop, a study was conducted to evaluate the effect of tillage system (conventional, no-till, broadcast-disc, and ripper-roller) and seeding rate (1.12, 5.60, 10.09 and 14.57 kg seed ha-1) on the performance of B. carinata. A randomized complete block design with a strip-plot restriction on randomization and four replications was implemented in Headland, AL, Jay, FL, and Quincy, FL, over five site-years during the 2017-18 and 2018-19 growing seasons. Data was collected on soil residue cover; plant population; soil penetrometer resistance and moisture; biomass (including carbon and nitrogen); stalk diameter; yield and yield components; seed oil, protein, and glucosinolates concentration; and oil composition. Soil penetrometer resistance was significantly affected by tillage system, with the ripper-roller consistently having the lowest penetration resistance values across all site-years. Ripper-roller tillage had the highest oil content and lowest protein and glucosinolates contents. Yield response to tillage system was variable. Among seeding rate treatments, yield was lowest at 1.12 kg seed ha-1 and similar among 5.60, 10.09, and 14.57 kg seed ha-1 at all site-years. There was no tillage by seeding rate interaction for yield. Results indicate that among seeding rates treatments used, 5.6 kg seed ha-1 rate was optimal at all site-years regardless of land preparation method and is thus the recommended seeding rate for commercial carinata production in the Southeastern United States.