Field evaluation of early maturing oilseed sunflower double-cropped after winter camelina

Authors: Gesch, Russell - Russ; Hulke, Brent; Anderson, James

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/9/2020
Publication Date: 4/7/2020
Citation: Gesch, R.W., Hulke, B.S., Anderson, J.V. 2020. Field evaluation of early maturing oilseed sunflower double-cropped after winter camelina. In: Proceedings of the National Sunflower Association. 42nd National Sunflower Association Research Forum, January 8-9, 2020, Fargo, North Dakota. Available: https://www.sunflowernsa.com/uploads/research/1363/NSApaper_RGeschfinal.pdf.

Interpretive Summary: Sunflower growers are looking for ways to increase their net returns and diversify their agricultural systems. Double-cropping sunflower after winter camelina may be a means of doing this, while also adding ecosystem services like weed suppression and reduced soil erosion by growing camelina as a cash cover crop. Winter camelina can be harvested by early July, and improved semi-dwarf early maturing sunflower hybrids have been developed by ARS that might serve as an excellent second crop after camelina harvest. To test this hypothesis, a 2-year field study was conducted in western Minnesota to evaluated three commonly grown commercial sunflower hybrids along with an early maturing hybrid called Honeycomb in a double-crop scenario after camelina harvest and compared with the same hybrids grown as monocrops planted at a near normal time. In both years of the study, the growing season was unusually wet and cold especially in spring, causing camelina to be harvested one to two weeks later than normal. Nevertheless, Honeycomb planted as a double crop after camelina reached full harvest maturity by mid- to late October. Although the combined total seed yields (i.e., camelina + sunflower seed) of the double-crop treatments were not as high as the yields of the monocrop control sunflowers, in the second year of the study, they were on average 61% greater than the single full-season sunflower yields. Results clearly showed that even under a short growing season, double cropping an early maturing sunflower with winter camelina is feasible. Moreover, results also indicated that there is potential to produce more total seed and oil per acre by double-cropping than growing a single full-season sunflower crop, while also reaping the environmental benefits of growing a cover crop.

Technical Abstract: In the northern Great Plains and upper Midwestern U.S., incorporation of winter-hardy crops and cover crops as components of integrated weed management systems is gaining popularity as an approach for managing the spread of herbicide-resistant weeds. However, to develop new rotational cropping systems suitable to these regions, there is a need for major commodities, such as early maturing sunflower, that can be relay- or double-cropped with economically-viable winter cash crops and/or cover crops. Because relay- and double-cropping often require delayed planting dates, these early maturing commodities also need to maintain acceptable yields under the dryer and warmer late season growing conditions. The identification of early maturing oilseed sunflower varieties with high omega 3 fatty acid profiles opens opportunities for developing new rotational multi-cropping systems suitable for the northern Great Plains and upper Midwestern regions that additionally provide ecosystem services. Preliminary studies demonstrated that double cropping early maturing sunflower after the harvest of winter camelina in Morris, MN, in 2018 reduced seed yield from 3400 kg/ha to approximately 1700 kg/ha compared to conventionally mono-cropped sunflower. However, one also needs to consider the value-added ecosystem benefits and value of the oilseed harvested from the winter cash crop. Outcomes from a two-year study conducted in Morris, MN, will be presented.