Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2006
Publication Date: 2/1/2007
Citation: Forcella, F., Spokas, K.A., Gesch, R.W., Isbell, T., Archer, D.W. 2007. Swathing and Windrowing as Harvest Aids for Cuphea. Agronomy Journal. 99: 415-418.
Interpretive Summary: Cuphea is a potential new oilseed crop for northern regions in the USA. Harvesting problems occur because current varieties are prone to seed shattering. We investigated the effects of swathing and delayed combining on windrow weight, seed moisture, and seed yield. Windrow weights and seed moisture decreased 60-65% as combining was delayed after swathing from 0 to 3 weeks. Weight losses were associated closely with evaporation after swathing. Seed oil content was affected only slightly by delayed combining dates. Thus, swathing cuphea and then delaying combining until after the occurrence of about 1.5 inches of evaporation had the following beneficial effects: (a) decreased weights of swathed material processed by combines, (b) reduced seed moisture and artificial drying costs, and (c) sustained high seed yields and seed oil contents. These results can be implemented easily by farmers who wish to grow this new crop, as well as by extension educators and agri-business personnel who provide advice to such farmers.
Technical Abstract: Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton) is a potential new oilseed crop for temperate regions. Harvesting problems occur because current varieties are non-determinate and shatter seeds. We investigated the effects of swathing and combining of windrows at weekly intervals on windrow weight, seed water content, and seed yield. Windrow weights decreased from about 40 to 14 Mg ha-1 as combining was delayed after swathing from 0 to 3 weeks. Weight loss was associated hyperbolically with post-swathing evaporation (Eps). Similarly, seed water content decreased from about 0.67 g g-1 at swathing to about 0.25 g g-1 at 40 mm Eps. Seed shattering apparently was low, and high yields were maintained each year until after 40 mm Eps. Seed oil content was affected only slightly by delayed combining dates. Thus, swathing cuphea and delaying combining until 40 mm Eps substantially decreased the weight of swathed material processed by the combine, reduced seed water content, but maintained high seed yields and seed oil contents.