PEA, AS A FIELD CROP. Pisum sativum, var. arrcnsc, Poir. Leguminoste. Figs. 732-734.
The pea is grown as a field crop for the produc tion of grain for stock-feeding 'and for the manu facture of "split peas" for culinary use, for canning in the factories, for forage and green-manuring and to supply the seed trade.
The pea is the most important member of the genus Pisum. It is native to Europe, but has been cultivated from before the Christian era for the rich seeds. It is an annual, glabrous and glaucous, tendril-climbing ; the stipules are large and leafy ; the leaflets are oval or ovate, two to three pairs, the leaf ending in tendrils ; the flowers are few, on an axillary peduncle. The field- or stock-pea differs from the garden pea usually in its violet or purple rather than white flowers, its smaller and more uniformly smooth seeds, but chiefly in the less tenderness and sweetness and lower quality of the green seeds.
History.
The pea is generally supposed to be a native of southern climates and was well known both to the Greeks and to the Romans, frequent mention being made of it in the works of old writers on rural subjects. A form of gray pea still growing wild in Greece is supposed by some to be the original form of all the highly domesticated varieties be longing to the species. The pea has been known and cultivated in England for centuries. Most of the early English writers on agricultural topics mention it either as a garden vegetable or as a farm crop. Lydgate, a writer in the time of Henry VI, speaks of peas as being hawked about the streets of London. It seems to have been more ex tensively used as a garden vegetable in England before the introduction of the potato than during recent years.
In the United States the practice of canning green peas, thus rendering them available through out the year, has led to their being extensively used by the well-to-do classes. The area now de voted to canning peas very largely exceeds that planted to stock-peas.
Distribution.
Peas thrive best in localities having somewhat cool summer temperatures and a rather abundant supply of moisture. For grain and seed production the southern parts of Canada and the northern belt of the United States seem to be best suited. Farther south fruiting is less certain owing to liability to hot weather, though the crop may have value for forage and green-manuring purposes.
Pea-growing has received much attention in Canada, the average annual production of the province of Ontario alone during the last twenty years being nearly 14,000,000 bushels. The greater part of this large crop is fed to live-stock. In the United States the crop has received less attention than it deserves. In Michigan, Wisconsin and lilon
tana great increase in the area devoted to peas has occurred in recent years, while in New York the production of stock- and seed-peas has very materially declined, while the production of canning peas has largely increased.
Peas may be grown successfully for green manure or forage purposes in many regions where climatic conditions are not favorable for a good yield of seed, and they may be raised successfully for canning or marketing in the green state where, because of insect infestation, the matured seed is of little value. This leads to certain favored local ities making a specialty of seed-pea production. Formerly Jefferson county, New York, was the cen ter of the seed-pea industry of the United States. More recently, owing to the advent of the pea weevil and the pea louse, the industry has largely been removed to Michigan, Wisconsin and the state of Washington.
Varieties.
The varieties of peas are numerous and are of two general classes: the field-peas, grown for stock food and for the production of "split peas" of the markets, and the sweet, wrinkled or vegetable peas grown largely for canning and for consumption in the green state. The field varieties in the United States are usually classed together as "Canada field peas." The Ontario Experiment Station at Guelph has tested many varieties of field-peas, mostly secured from Europe. Among the most successful varieties are the Prussian Blue, Canadian Beauty, Tall White Marrowfat, Early Britain, Mummy and Golden Vine. The last-named variety is very largely grown and is the one usually met with under the name "Canada pea." Of the vegetable peas there are many varieties. They differ from the field sorts principally in con taining more sugar, which increases palatability, and many of the varieties have wrinkled seeds while the field sorts are smooth. The wrinkled varieties usually produce white flowers, while the smooth sorts have colored (mostly purple) blooms. They vary greatly in habit of growth, being dwarf or large ; early, medium or late ; and in quality, from moderately to very sweet. Many of the dwarf, early varieties are smooth and only moderately sweet, while the late, large varieties are wrinkled and much sweeter. The varieties named below are grown largely for canning or for marketing in the green state. In a careful test made a few years ago by N. B. Keeney & Son, LeRoy, N. V., it was found that the number of days from planting to fruit picking was: so that the taproots will reach it during the seed forming period.