A review of research progress on cicer milkvetch (Astragalus cicer L.)

Abstract

This review of cicer milkvetch includes both published and unpublished information regarding crop and seed characteristics, seed treatments, breeding, agronomic practices and nutritional value for livestock. Cicer milkvetch is a long-lived perennial, acid- and drought-tolerant crop providing high-quality forage throughout the growing season. It does not cause bloat in ruminants. Although it has caused photosensitization in ruminants, this was apparently due to specific environmental conditions and the cultivar used. Cicer milkvetch is compatible with other forage crops in mixed stands and is particularly suitable for pasture. Although the crop has many good qualities and was introduced in North America approximately 75 yr ago, it has not been utilized extensively, primarily due to slow establishment. However, stand establishment has been improved by elucidation of seed and seedling characteristics, followed by selection for heavy seed, rate of emergence, and mature plant vigor. Improved cultivars, developed through recurrent selection for rapid establishment, are now available. Seed scarification, inoculation with rhizobia, and shallow seeding into a pre-packed, warm seedbed are of great importance in cicer milkvetch establishment. Seeding later in the spring (without a companion crop) increases the probability of successful establishment of genetically improved cultivars. Development of cultivars with upright growth characteristics and long-term persistence under grazing stress, improved scarification techniques (to reduce seed loss), and a seeding protocol for successful establishment of the crop, have the potential to substantially increase utilization of this important forage legume. Key words: Cicer milkvetch, forage legume, hard seed, seed scarification, seedling vigor, stand establishment