Cover Crop Diversity through Evaluation and Increase from Breeder Stocks and Germplasm Repositories

View the project final report

• 2017 annual report

Commodities

Practices

• Crop Production: cover crops
• Production Systems: general crop production

Cover crops provide a range of agroecosystem services that can improve soil health and increase the sustainability of crop production. In conventional systems, cover crops can be particularly useful as part of integrated management of pests and weeds in buffer zones where soil fumigation is not permitted. Cover crops are a required component of organic cropping systems that are critical for a holistic approach to crop, soil, and pest management. The purpose of this project is to increase the diversity and availability of cover crops adapted to the southeastern United States in general and Florida in particular with the potential to improve soil health, serve as green manure, and suppress weeds and nematodes. Research is proposed that will involve increase and evaluation of germplasm of the leguminous cover crops Crotalaria juncea (sunn hemp), Crotalaria ochroleuca (slenderleaf rattlebox), Vigna unguiculata (cowpea), and Indigofera hirsuta (hairy indigo) that is not currently commercially available but has the potential for overcoming some of the constraints of existing commercial varieties such as hardseededness and the inability to set seed in Florida. The site-specific nature of cover crop performance and the differing host susceptibility of accessions within a cover crop species to plant pathogenic nematodes underscore the need for greater cover crop diversity. Alternative germplasm of these species will be obtained that have high potential for utility as cover crops but are not currently commercially available. The germplasm will be multiplied to obtain sufficient seeds for replicated field evaluation and will be assessed at the Plant Science Research and Education Unit in Citra, FL as well as at farms in Gainesville, Hawthorne and Stuart, FL. ‘Flamingo’ a hairy indigo cultivar that already produces fewer than 10% hard seed will undergo a selection process to further reduce or eliminate hard seed. Cover crop growth, nematode and weed suppression and seed yield will be assessed in comparison with commonly available commercial species. The education and outreach component of our project includes: (1) an on-farm field day in the third year of the project, (2) a virtual field day in years two and three, (3) a project website and blog, and (4) and in-service training webinar for county Extension faculty and other service providers. Small amounts of seed will be made available to interested growers of the most promising accessions/cultivars/germplasm lines. Results will be presented to peers at scientific conferences and published in refereed journal articles.

1. Multiply seeds of cover crop species and accessions with high potential for utility but are not currently commercially available to obtain sufficient amounts for replicated field evaluation.
2. Select for the soft-seed trait in ‘Flamingo’ hairy indigo.
3. Evaluate on-station and on-farm for ecological services in comparison with commonly available commercial species.
4. Provide recommendations and make seed available for the most promising species/accessions.