Yellow field pea has suddenly joined the list of alternative crops, as a result of a promotion aimed at producers in Central and Southern Illinois.

"As far as we know, this crop has never been grown commercially in this part of Illinois, and there has been no research to see how well or consistently it might perform," said Emerson Nafziger, crop scientist with University of Illinois Extension. "Some producers in Northern Illinois did produce relatively good yields in 2003, under unusually cool weather conditions in May and June."

Field pea is a cool-season crop that is grown for food and feed. Almost all of the U.S. production is in North Dakota and the states west of it, bordering Canada. The U.S. production area generally has annual rainfall less than 20 inches.

"Field pea is basically the same crop as the peas that gardeners grow, but it stays in the field until seeds are dry and hard, and it has a smooth instead of wrinkled seedcoat," Nafziger said. "Worldwide, yields of 30 to 35 bushels per acre are considered good, partly because the crop tends to be grown in areas with rainfall or temperatures too low to produce higher-yielding crops."

Nafziger points out that cool weather is especially important for dry pea production. The crop often grows with very little seasonal rainfall, sometimes on residual soil moisture only.

"It does respond to moderate rainfall, as long as temperatures stay down, preferably below 75 F," he said. "If it gets hot or warm and wet, the crop will deteriorate rapidly, and yields can be very low."

To increase chances of getting favorably cool weather during the growing season, field pea in Central and Southern Illinois should be planted in March. The varieties currently being promoted are from Canada, and have not been tested in Central or Southern Illinois.

"Maturity is said to range from 90 to 100 days, but it is not known what the actual duration will be if the crop is planted in early March, especially if it turns cold after planting," Nafziger said. "The seed needs to be inoculated with the inoculant strain specific to pea."

He notes that, contrary to claims, pea will not interrupt all important disease and pest cycles in the corn-soybean rotation. Pea is a host for soybean cyst nematode, and is very susceptible to Sclerotinia white mold, which is present in most fields and which also can affect soybean.

"As a new crop, pea may suffer less from some diseases than other crops, simply because disease inoculant may not have built up," Nafziger said. "On the other hand, if there is warm, wet weather in May and June, diseases could well become a serious problem."

According to the current promotion, economic viability of field pea as a crop depends on a successful doublecrop with soybean or some other crop planted following pea harvest.

"We expect the pea crop to be ready for harvest at about the same time as winter wheat, unless wet weather leads to serious crop deterioration and low yield," Nafziger said. "In Central Illinois, this means that doublecropping of soybean after pea may have about the same success rate as soybean following wheat harvest."

Nafziger points out that many producers in Central Illinois consider doublecrop soybean after wheat to be only marginally profitable, due to the frequency of low yields.

"Some growers attempt to doublecrop only if the wheat harvest is early and there is soil moisture to get the next crop up," he said. "The nitrogen that field peas are said to supply to the next crop would not raise yield of a following soybean crop, and diseases that might carry over from pea to soybean are a concern."

He adds that the current contract price of $3.50 per bushel for pea will only be realized if the peas grade U.S. No. 1.

"We do not know how likely it is that Illinois-grown peas will meet those standards," Naziger said. "The crop in Northern Illinois, responding to unusually good weather in 2003, yielded about 50 bushels per acre, though some quality problems were reported. Even if such yield levels are reached again, it is not clear how peas can compete with soybean at average yield levels, when soybean sells for more than twice the price of peas."

Nafziger points out that alternative crops and markets for Illinois are worth pursuing, especially because the state has the type of innovative producers and good soils that can help make alternative crops work.

"Crops with good potential, though, are ones that we know will yield well under typical weather conditions, and that have a high market price relative to existing crops, such that risk of low yields is offset by high prices," he said. "Field peas do not match these criteria very well; they are priced low relative to soybean, and yield potential is similar to that of soybean only if the weather cooperates unusually well."

He notes that the combination of low price and yield risk, along with uncertainty regarding diseases, doublecrop yields, crop quality, and other unknowns, tends to move field pea down the list of economically promising alternative crops.

"A large part of the reason that field pea has not been tested or grown in Central and Southern Illinois is that Illinois does not have a clear comparative advantage over other places in the world where the crop now grows," Nafziger said. "As with other crops that carry some risk, field pea should be tried with caution, by those who have both curiosity and soils most likely to allow early planting. This should be done on as small an acreage as possible, at least until we can learn better what to expect from this crop."