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Title: Influence of Seeding Rate and Row Spacing on Cuphea Seed Yield in the Northern Corn Belt

item Gesch, Russell - Russ
item KIM, KI-IN

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2010
Publication Date: 9/29/2010
Citation: Gesch, R.W., Kim, K., Forcella, F. 2010. Influence of Seeding Rate and Row Spacing on Cuphea Seed Yield in the Northern Corn Belt. Industrial Crops and Products. 32:692-695.

Interpretive Summary: Cuphea is a newly-domesticated oilseed crop that can be grown in the northern U.S. The oil produced by cuphea seed is similar to that of tropical plants such as oil palms. Improving recommendations of how to grow cuphea in the field will help increase its seed yield. Our past work has generally shown that cuphea can be planted on a relatively wide range of row widths without sacrificing yield, but we do not know what the best seeding rate is to use. This is important because a farmer wants to plant enough seed to get the highest yield possible without planting too much seed, which is usually a major input cost. In the study we conducted, we used three planting rates of 4, 8, and 12 lbs. of seed per acre and did this for three different row spacings of 15, 22, and 30 inches to see what combination of seeding rate and row spacing result in the greatest yield. We found that a planting rate of 8 lbs/acre and row spacing of 22 inches gave the highest yields. This information will be used to make improved recommendations to farmers raising cuphea to help increase their yields. The improved recommendation for planting rate will help farmers avoid planting more seed then necessary to achieve high yields; thus, saving them money with respect to their input costs.

Technical Abstract: Cuphea (C. viscosissima Jacq. X C. lanceolata W.T. Aiton; PSR23) is a new oilseed crop adapted to temperate climates that provides a rich source of medium-chain triglycerides. Although prior research indicated cuphea seed yield is not greatly affected by row spacing due to its indeterminate growth, little is known about optimum seeding rate. The present study was designed to test effects of varying seeding rate with row spacing on seed yield. Seed was sown at rates of 4.5, 9.0, and 13.4 kg ha-1 in 380, 560, and 740 mm spaced rows in west central Minnesota during 2002 and 2003. Row spacing had a modest affect with the 560 mm spacing yielding 65 and 127 kg ha-1 greater than the 380 and 740 mm widths, respectively. However, the effect was more pronounced in 2003 under potentially water-limiting conditions. Seeding rate did not have a significant effect, although generally yields were 9 and 20% greater for the medium seeding rate than the lower and higher rates, respectively. The interaction of row spacing and seeding rate was not significant. Based on results, a seeding rate of 9.0 kg ha-1 and row spacing of 560 mm are recommended for cuphea production. However, where presently recommended herbicides for cuphea may not sufficiently control dominant weed species, row spacing of 560 mm or greater may be necessary to facilitate mechanical weed control.