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ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Publications at this Location » Publication #170780
Title: SEED YIELD, OIL, AND FATTY ACIDS OF CUPHEA IN THE NORTHWESTERN CORN BELT

Author
item Forcella, Frank
item Gesch, Russell - Russ
item Isbell, Terry

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2005
Publication Date: 9/23/2005
Citation: Forcella, F., Gesch, R.W., Isbell, T. 2005. Seed yield, oil, and fatty acids of cuphea in the northwestern Corn Belt. Crop Science. 45:2195-2202.

Interpretive Summary: Cuphea is a potential new crop for northern growing regions. Its seeds contain oils that are similar to those from seeds of tropical palms and, therefore can replace such oils in the marketplace. The growth and yield potential of a cuphea variety known as 'PSR23' was known for central Minnesota, but not elsewhere. To better understand the regions in which 'PSR23' is adapted, planting date experiments were performed at seven research farms from southwestern Iowa to northwestern Minnesota during 2002 and 2003. Seed yields and seed oil contents were determined. Cuphea grew well at most sites, but seed yields tended to be higher in Minnesota than in Iowa. Irrigation did not increase seed yields greatly in Iowa. Low yields due to delayed planting occurred only when summer rainfall and/or irrigation were limited. Oil content of seed averaged about 30%. The primary component of this oil was capric acid, which averaged about 70% of total oil. Capric acid levels always were higher in northern Minnesota than southern Iowa. Why 'PSR23' cuphea did not yield well in Iowa was unclear, but its relatively high yield potential in Minnesota was confirmed. These results are important for the oilseed industry and growers of oilseed crops, as the information allows for initial recommendations for where cuphea currently is adapted and can be expected to perform well agronomically.

Technical Abstract: Cuphea is a potential new crop for temperate regions. It produces and stores in its seeds medium chain length fatty acids, which currently are derived commercially from seeds of tropical palms. The growth and yield potential of 'PSR23' cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton) was known for central Minnesota, but not elsewhere. To better understand the range of latitudes in which 'PSR23' is adapted, planting date experiments were established at seven research farms along a transect from southwestern Iowa to northwestern Minnesota (41.3 deg to 48.8 deg N latitude) in 2002 and 2003. Seed yields, seed oil contents, and fatty acid compositions of seed oil were determined. In the absence of drought, cuphea grew well vegetatively at most sites, but seed yields tended to be higher in Minnesota than in Iowa. Irrigation did not enhance seed yields greatly in Iowa. Low yields due to delayed planting (mid May to mid June) were apparent only when summer rainfall and/or irrigation was limited. Oil content of seed ranged from 28 to 33% and was not related consistently to site. The principal fatty acid was capric acid, which ranged from 67 to 73% of total oil, and was always highest in the northern-most latitudes. Why 'PSR23' cuphea did not yield well in Iowa was unclear, but its relatively high yield potential in Minnesota was confirmed.