Title: Proso Millet Yield and Residue Mass Following Direct Harvest with a Stripper-header Authors
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 20, 2007
Publication Date: May 8, 2008
Citation: Henry, W.B., Nielsen, D.C., Vigil, M.F., Calderon, F.J., West, M.S. 2008. Proso Millet Yield and Residue Mass following Direct Harvest with a Stripper-Header. Agronomy Journal 100:580-584. Interpretive Summary: Proso millet generally requires a swathing operation to promote uniform drying of the seed before combine harvest. But this operation adds to the harvest cost of this low-input Great Plains crop. A stripper-header could be used to harvest the crop, thereby eliminating the swathing operation and leaving more surface crop residues, but requiring a delay in harvest so that more seed could ripen and dry to acceptable harvest moisture condition. This delay could result in more seed loss by shattering and lower harvested yield. This study compared proso millet yield and post-harvest crop residue from both conventionally swathed and stripper-header harvesting methods. No yield differences were found between the two harvest methods, and significantly more residue remained on the ground and standing following stripper-header harvest. A stripper-header can be used to successfully direct harvest proso millet thereby reducing harvest costs and increasing surface crop residues following harvest, which should enhance precipitation storage and erosion protection.
Technical Abstract: Proso millet (Panicum miliaceum L.) (PM) is an important crop for dryland agricultural rotations in the central Great Plains. The crop is traditionally swathed prior to combining to promote uniform drying of the panicle and to minimize seed shattering losses. Direct harvesting of PM with a stripper header would eliminate the swathing operation resulting in cost savings and increased standing crop residues to enhance erosion protection, snow catch, and precipitation storage efficiency. This study was conducted to determine yield differences between conventionally swathed and stripper-header harvested PM and to compare PM residue mass and orientation following the two harvest techniques. The study was conducted over four growing seasons at Akron, CO. PM was harvested either by swathing and then picking up the swath with a combine, or by direct harvesting with a stripper-header attached to the combine. Seed yields and seed moisture contents at harvest were not different between treatments. About 24% more seed was found on the ground with the stripper-header harvest than with the conventionally swathed harvest, but the increased shatter was relatively small and unimportant to final yield (about 1% of the average final yield). Using a stripper-header resulted in much greater mass of standing residue following harvest which caused the silhouette area index to be four times greater than in conventionally swathed PM. A stripper-header can be used to successfully direct harvest PM thereby reducing harvest costs and increasing surface crop residues following harvest.