AMERICAN JOINT VETCH
American Joint Vetch, Pega pega (ES), Deer Vetch, Aeschynomene
The American Joint Vetch is native to the Caribbean and nearby regions of the Americas. It is found in South America south to Argentina and northward into southern Florida. It has been introduced in Southeast Asia into countries such as Vietnam, Thailand and the Philippines.
American Joint Vetch is used alone as a hay crop or as cut-and-carry forage for livestock. It frequently is sown as a pasture legume in Florida and along Australia's eastern coast. The leaves and young stems are palatable to grazing animals. It has been used as a green manure crop in rice and other cropping systems. American Joint Vetch is also a legume that fixes nitrogen equivalent to the application of up to 100 lb/acre (112 kg/ha) of nitrogen fertilizer.
- American Joint Vetch can be grown successfully between latitudes 30o north and south of the equator. It also grows well in low-lying areas and ditches. As an annual or short-lived perennial, joint vetch propagates readily from seed. For best establishment, plant at the onset of the rainy season. The seeds can be sown in the pods or, preferably, de-hulled. A suggested seeding rate is 12 kg/ha (10 lb/acre) seed-in-the-pod or 5.6 kg/ha (5 lb/acre) de-hulled seeds. Half these rates may be used in mixed species seedlings. Bare soil seeding yields higher establishment rates than pasture seeding but prior disking or other surface cultivation often will provide for an adequate establishment in pasture situations. Rolling the soil the same day after seeding packs the soil around the seed, conserves soil moisture, and improves germination. American Joint Vetch produces nodules readily using broad spectrum cowpea rhizobia. In pastures, American Joint Vetch should be kept grazed to a height of 50-60 cm to stimulate leaf production. After flowering, grazing should be reduced to promote seed production. To stimulate seed germination in the following year, graze the pasture closely until American Joint Vetch germination begins.
- Soil: any - from gravels and sands to clays; can tolerate waterlogged soils
- Elevation: 0-670 m (2200 ft)
- Temperature: 20-27º C (65-85º F)
- Rainfall: 600 mm (20 in) or more
Harvesting and Seed Production
For use as a hay crop, cut American Joint Vetch at the full flower stage. As a green manure, American Joint Vetch should be plowed under also at the flowering stage. To use the plant as cut forage, cut at about 40-50 cm to encourage additional growth. For seed production, allow the seeds to ripen on the plant until mature. Do not graze newly seeded pastures until the new plants have attained a height of 18 in (45 cm). Rotational grazing is recommended. Overgrazing reduces American Joint Vetch productivity and seed production. Undergrazing, can suppress the growth of companion grasses and increase insect damage.
Pests and Diseases
Mildew (Oidium spp.) infects mature leaves near the end of the growing season turning them white. This type of infection normally does not affect palatability or feed quality. Anthracnose (Colletotrichum gloeosporioides) is reported on South American populations of American Joint Vetch.