Development and Dissemination of a Cowpea Cultivar for Cover Crops

Project Overview

Project Type: Research and Education
Funds awarded in 2002: $43,686.00
Projected End Date: 12/31/2007
Matching Federal Funds: $18,974.00
Region: Western
State: California
Principal Investigator:
Dr. Milt McGiffen, Jr.
University of California

Annual Reports


  • Agronomic: potatoes, grass (misc. perennial), hay
  • Fruits: melons, berries (strawberries)
  • Vegetables: artichokes, asparagus, beans, beets, broccoli, cabbages, carrots, cauliflower, celery, cucurbits, eggplant, garlic, greens (leafy), lentils, onions, parsnips, peppers, rutabagas, sweet corn, tomatoes, turnips, brussel sprouts
  • Additional Plants: herbs, ornamentals


  • Animal Production: feed/forage
  • Crop Production: cover crops, multiple cropping, no-till, nutrient cycling
  • Education and Training: farmer to farmer, on-farm/ranch research, participatory research
  • Pest Management: allelopathy, cultural control, mulches - killed
  • Production Systems: general crop production
  • Soil Management: green manures, organic matter
  • Sustainable Communities: new business opportunities


    Cowpea cover crops are cost effective because they enrich the soil with carbon and over 100 lbs per acre of nitrogen, and can reduce pest populations. Adoption has been slowed by a lack of varieties specifically adapted to production systems in the western USA. Cowpea varieties can be selected that grow prostrate, semi-erect or erects and these characteristics have important implications with respect to weed competition and agronomic suitability. A new statistical method for determining whether one group of cultivars is distinct from another was developed and used, along with growth analysis and computer modeling, to show that the erect growth habit trait consistently conferred greater weed resistance across cultivars and weed species. In the last year we were able to identify two additional promising candidates for varietal release. The existing and new candidate cultivars produce high biomass and seed yields and have resistance to root knot nematodes, and seed shattering. The ability to withstand drought was similar for all genotypes. The candidate cultivars are currently being tested on farms in specific cropping situations to evaluate their suitability for varietal release. Information is being disseminated through talks, publications, and organic production training sessions and a manual.

    Project objectives:

    1. 1) Identify cowpea cover crop cultivars that resist nematodes, cowpea aphid, Fusarium wilt and shattering when grown in the Western USA.
      2) Disseminate seed of improved varieties and related information through the California Foundation Seed Service and commercial seed companies.
      3) Demonstrate and optimize the merits of cover crops in specific cropping systems.
      4) Disseminate information about cover crops and their advantages, and about seed production of cowpea as a new crop for limited resource and other growers.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.