In the U.S. Upper Midwest where growing seasons are short, establishing winter annual cover crops following corn (Zea mays L.) is challenging. Winter camelina [Camelina sativa (L.) Crantz] shows promise as a winter annual cover crop that can be dual cropped with soybean [Glycine max (L.) Merr.] to help diversify the corn–soybean rotation. This 2-yr field study in southern and western Minnesota evaluated desiccating corn with a preharvest aid to hasten its dry-down and hence harvest so that camelina could be no-till drilled in a timely manner. We hypothesized that direct drilling camelina following corn harvest would improve establishment and yields. Sodium chlorate was applied as a desiccant to corn at early (D1) and mid-R5 (D2) and physiological maturity (D3) stages of development, including an untreated check. The D1 and D2 treatments hastened corn harvest by 1 to 3 wk compared with the check. Corn grain yields were unaffected by the D2 and D3 treatments, but significantly declined by 16% in D1. Camelina seed yield did not differ among desiccation treatments and averaged 815 kg ha−1 across both locations with an average oil content of 385 g ka−1. Desiccating corn hastened its harvest allowing more time to drill-seed camelina, thus improving establishment. However, more work is needed to improve management and genetics of winter camelina for use as a cash cover crop in corn systems.
Bibliographical noteFunding Information:
This research was supported by the U.S. Department of Agriculture, Agricultural Research Service.
The authors wish to thank Joe Boots, James Eklund, Chuck Hennen, and Scott Larson for their expert field assistance in maintaining the study at the Morris field site and in helping to collect data. The authors also thank Riley Ellarson for his expert assistance in helping to maintain the Rosemount field site and collecting data. We especially thank Gary Amundson for designing the desiccant application (i.e., sprayer) device used on the highboy tractor (Avenger) used in the study. This research was supported by the U.S. Department of Agriculture, Agricultural Research Service.
© 2021 The Authors Crop Science © 2021 Crop Science Society of America. This article has been contributed to by US Government employees and their work is in the public domain in the USA.