If you're looking for an annual forage crop that packs plenty of protein and offers the convenience of one cutting, one of three new soybean varieties might fill the bill. These recently released forage beans distinguish themselves at first glance: They can grow over 6' tall.

But it's their performance and not just their appearance that's attracting attention. In research and on-farm test plots, they've produced dry matter yields topping 6 tons/acre and crude protein levels ranging as high as 17-22%, depending on management and conditions.

Combine those figures with wide windows for spring planting and fall harvest, and you've got a productive, yet low-maintenance forage crop, say researchers.

The three varieties are Donegal, Derry and Tyrone. They were developed by Tom Devine, geneticist at USDA's Weed Science Lab, Beltsville, MD, in cooperation with Elwood Hatley at Penn State University and David Starner at Virginia Tech.

Donegal, a Group V variety recommended for Pennsylvania, New York and the New England states, is a high yielder, producing nearly twice the dry matter of grain-type varieties. Its leaf size is often 50% larger than normal grain soybeans, which helps it develop a denser canopy.

Derry is a Group VI variety, suggested for the northern Midwest. It's exceptionally tall with good late-season standability.

Tyrone, the latest maturing of the three, is a Group VII variety intended for the Southern states.

One of the biggest benefits of the new beans, says Devine, is that they offer farmers greater flexibility in their forage plans.

"These varieties can be grown with sorghum-sudan grass, corn, grain sorghum or millet; or they can be planted as a strip crop," he says. "They also have various crop uses, such as for green manure, mulch, hay or silage." One Missouri researcher is even exploring the crop's grazing potential.

Throughout the normal growing season, these beans may not look much different than grain-producing varieties, say most researchers who've worked with them. "The added height of these plants comes in the last quarter of the season," says Devine. T hese soybeans have produced good forage yields in both wet and dry years, and have shown good adaptability to a variety of field conditions, report researchers and agronomists. But be aware of these management considerations:

* Make sure your soil's pH is in the 6.5 to 6.7 range.

* Use an inoculant if you have not grown soybeans on the field recently.

* Plant in narrow rows to encourage fast crop canopy development and weed control.

* Select herbicides that have no label restrictions for feeding the crop.

*Plant 175,000-200,000 seeds per acre - the same as for conventional soybeans.

Limited quantities of seed are available from three companies this year: Seedway of Hall, NY; Wolf River Valley Seed Co., White Lake, WI; and Southern States Cooperative, based in Richmond, VA. Prices range from $20 to $25 per bag.