When it comes to planting and establishing corn in a cereal rye cover crop, the growing corn can be adversely impacted by rye’s allelopathic effects, the release of chemicals that inhibit the plant’s growth.
But rye can also limit the amount of light, and quality of light, available to corn when it’s growing in the cover crop. On this episode of the RealAgriculture Corn School, PRIDE Seeds market agronomist and University of Guelph graduate student Olivia Noorenberghe gives growers a snapshot of what she’s learning in her research work on the best strategies for successfully planting corn in rye.
Noorenberghe is evaluating three different variables beginning with termination herbicides. Will a fast-acting herbicide such as glufosinate reduce the duration of poor-quality light from neighbouring green vegetation versus a slower-acting herbicide like glyphosate?
Noorenberghe also looks at cereal rye planting patterns, comparing corn planted into traditional 7.5-inch seeded rye and a twin-row rye system. Here, two rows of rye are planted followed by two skipped to allow room for the corn to be planted. This pattern is repeated across the field. These trials will evaluate whether the rye-free space will allow for quicker corn germination and encourage the plant to grow more effectively early in the season.
The final aspect being investigated is termination timing. Noorenberghe is comparing four different timings — two weeks before planting, one week before planting, one day before planting and one week after planting. She notes that the most effective timing will be dependent on the farmer’s management goals: whether they are trying to maximize biomass, optimize yield or a combination of both. (Story continues after the video.)
Noorenberghe will report her findings later this year when she concludes her research, but she does share some preliminary findings in the video. For grower looking to maximize biomass and optimize weed control, termination one day before planting to one week after planting appears to be the most effective application window. If yield is the ultimate goal, terminating early, up to 14 days before planting, is the best window.
When it comes to planting pattern, in the twin row planting arrangement the plants do receive a higher quality of light. Noorenberghe has seen a yield benefit at some research locations but will wait to see 2022 data before making a final conclusion. She does note, however, that weed control does appear less effective in the twin row pattern compared to solid seeing.
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