510 



PEA 



PEA 



New "York, 1904; Handbuch der Papier Kunde, 

 Klemm, Leipzig, 1904 ; Die Cellulose Fabrikation, 

 Schubert, Berlin, 1906 ; An Elementary Manual of 

 Paper Technology, Sindall, London, 1906 ; Philip- 

 pine Fibers and Fibrous Substances, Richmond, 

 Philippine Journal of Science, i., 433, 1906. 



PEA, AS A FIELD CROP. Pisum sativum, var. 

 arvense, Poir. Leguminosm. Figs. 732-734. 



By /. L. Stone. 



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 



Fig. 732. Keia-pea. 



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 Mon- 

 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 



