ARS | Publication request: ROTATIONAL EFFECTS OF CUPHEA WITH CORN, SOYBEAN, AND WHEAT IN THE NORTHERN CORN BELT

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 10, 2007
Publication Date: October 10, 2007
Repository URL: http://aaic.org/07progrm.htm
Citation: Gesch, R.W., Archer, D.W., Forcella, F. 2007. Rotational effects of cuphea with corn, soybean, and wheat in the northern Corn Belt [abstract]. Association for the Advancement of Industrial Crops. Available: http://www.aaic.org/07progrm.htm.

Technical Abstract: Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton; line PSR23) is a recently domesticated, new oilseed crop that can serve as a replacement for saturated small- and medium-chain fatty acids (i.e., C8:0 to C14:0) presently imported by the United States. Although diversifying crop rotations can have economic and environmental benefits, some species can negatively impact the following year’s crop through allelopathic effects, introduction of new pests or pathogens, or excessive depletion of subsoil moisture and nutrients. While management practices for growing cuphea have been developed, little is known about the effects of cuphea in rotation with conventional crops. In the northern Corn Belt where cuphea has been commercially produced, the predominant crops are corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.). A study was conducted in west central Minnesota from 2004 to 2006 to determine where cuphea might best fit into rotation with these crops. The experimental design was a strip plot randomized complete block replicated four times. The crops were initially planted in 9 m x 37 m strips in either a north-south or east-west orientation and then planted in the opposite direction the following year to give all combinations of the current and previous crop in a two-year rotational scheme. The main effect analyzed was the impact of the previous crop on the current crop. Cuphea seed yield and final plant population density were not affected by the previous crop (i.e., corn, soybean, wheat, or cuphea) in 2005 and 2006. In 2006, cuphea oil content was greatest when the previous crop was wheat (32% wt wt-1) and lowest when following corn (29.5%). Corn and wheat grain yields were unaffected when following cuphea in rotation, and yields tended to be similar to or greater than those in the establishment year (2004). In 2005, the yield of soybean when following cuphea in rotation was about 427 kg ha-1 lower than when the previous crop was corn or wheat. However, in 2006 there were no significant differences in soybean yields regardless of the previous crop. When soybean followed cuphea in rotation, final stands were 24 and 9% less in 2005 and 2006, respectively, than when corn was the previous crop. For west central Minnesota, evidence indicates that it may be best to rotate cuphea after soybean or wheat, and prior to corn or wheat. Results indicate that cuphea might negatively affect soybean that is planted the subsequent year although more research will be needed to verify this.