Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 7, 2006
Publication Date: November 16, 2006
Citation: Harrison Jr, H.F., Thies, J.A., Fery, R.L., Smith, J.P. 2006. Evaluation of Cowpea Genotypes for Use as a Cover Crop. HortScience. 41:1145-1148. Interpretive Summary: This research was conducted to develop methods to identify cowpea varieties that are suitable for use as a weed suppressing cover and to identify varieties most suited for use as a cover crop. A collection of 47 old forage varieties, experimental breeding lines, and land races collected in South Carolina were evaluated in a preliminary screening study, and 10 with superior characteristics were chosen for further testing. A four year study was conducted to compare the 10 selected cultivars with the standard cover crop cowpea variety, Iron Clay. All of the selections produced as much biomass as Iron Clay, and several exceeded Iron Clay in vigor and canopy size. This research demonstrates that vigor ratings and canopy measurements are a relatively simple, non-laborious approach can be used to identify suitable cover crop cowpea varieties. The differences between varieties that we observed indicate that developing a cowpea variety superior to Iron Clay is feasible. Several promising cover crop lines were identified.
Technical Abstract: A preliminary screening experiment was conducted to evaluate 47 cowpea genotypes for use as a weed suppressing cover crop. Of these, 10 were selected for further testing on the basis of their vigorous growth and weed suppressing ability. In a field experiment repeated over four years, the selected genotypes were not different from the leading cover crop cultivar ‘Iron Clay’ in biomass production. Vigor ratings, vine growth ratings and canopy widths of some genotypes exceeded those of ‘Iron Clay’ Vigor ratings and canopy measurements were efficient selection criteria that could be useful in breeding cover crop cowpea cultivars. The genotypes also varied in seed size, photoperiod, and response to diseases. This research indicates that developing cover crop cowpea cultivars superior to the leading cultivar, Iron Clay, is feasible.