Bigflower Vetch (Vicia grandiflora)
Plant Characteristics: Bigflower is a viney winter annual with compound leaves and narrow leaflets. Similar to common vetch, except that big flower has large 2 yellow or white flowers in the axils of the leaves. The long, slender stems of hairy vetch are weak and the plant uses tendrils to clasp onto other objects for support. The leaves of bigflower vetch are compound (more than 2 blades or leaflets) and have no terminal blade but instead end with tendrils.
Establishment: Vetch is a self-reseeding species and rapidly colonizes low fertility, open spaces. Vetch seed remains viable for 5 years or longer. When vetches are seeded following a cultivated crop, little seedbed preparation is needed. Seed is usually broadcast and disked in. On heavy clay soils, plowing and disking may be necessary before seeding. Recommended seeding rates vary from 20 to 25 lb/ac. Use lower rates when drilling and higher rates when broadcasting, drilling into a rough seedbed, or relay interplanting. Drill seed into a firm seedbed from 1/2 to 3/4 inch deep depending on soil moisture. If broadcasting, follow with a light disking to incorporate seed. If seed is relay planted, broadcast it before the final cultivation. If small grains are planted, they should be seeded at a rate of 60 lb/ac.
Diseases of vetches include anthracnose, leaf spot and downy mildew, several stem and root rots, and rust. Many of the insects of forage legumes attack vetches, including the pea aphid, cutworms, fall armyworm, vetch bruchid, American grasshopper, lygus bugs, clover leafhopper, and potato leafhopper. Hairy vetch is susceptible to root-knot nematodes and soybean cyst nematodes.
Fertilization: In high rainfall, low pH soil areas, Gypsum (calcium sulfate) is commonly applied at the rate of 75 to 150 lb/ac in areas with alkaline or low pH. This provides an adequate source of sulfur fertilizer, but will not correct soil acidity problems. When the pH is below 5.5, apply limestone for optimal production. Phosphorus fertilization is often required. An application of 60 lb /ac of P2O5 and 120 lb/acre of K2O should be adequate. However, where soil tests are very high (greater than 25 to 30 ppm P and 110 to 130 ppm K) applications can be eliminated. When planted alone, nitrogen fertilizer is not needed, as vetch obtains its nitrogen through symbiotic nitrogen fixation with bacteria in plant root nodules. If planted with a cereal grain or other grass, however, apply nitrogen at 75% of normal rates for grasses.
Grazing/Hay Management: Vetch can be use for pasture, hay or silage (in small grain mixture). Vetch lacks grazing tolerance and it is best utilized in rotational grazing. Seasonal production in the northern part of the state from March to May and in the southern part from November to December and February to April. Yields range from 1.5 to 3.5 tons/ac. When used as a pasture crop, it can be mixed with small grains or annual ryegrass. Vetch can be overseeded on warm-season grass sods to extend the grazing season and provide good beef steer gains. Grazing should be begging when plants have are 5 to 6 inches tall. Close grazing below the lowest leaf axil will remove axillary buds, resulting in slow regrowth.
Forage Quality: Bigflower vetch makes high quality hay, either grown alone or mixed with small grain. The protein content of vetch hay ranges from 12 to 20%, depending on the stage of development of the crop when cut. Low bloat potential.