312 FIELD CROP PRODUCTION 



days in the cock, the hay may be stored. When used for 

 silage, the cutting may be delayed until the beans are well 

 formed, as the loss in this case is slight, since the handling 

 is completed while the plants are green. 



When soy beans are harvested for the seed, they should 

 be cut after the pods have turned brown or black and 

 one-half or more of the leaves have fallen. A mower 

 with a side delivery attachment or a self-rake may be 

 used, which will prevent the shelling and loss of the beans 

 by the passing of the mower wheels over the cut swath. 

 After cutting they should be piled in cocks and allowed 

 to cure until ready for thrashing. When thoroughly 

 dry, they may be thrashed by tramping or with a flail, 

 although large acreages are best thrashed with an ordinary 

 grain thrasher, by removing the concaves and running the 

 machine at a slow rate of speed. After thrashing, the 

 beans should be spread out to dry before bagging or bulk- 

 ing in the bin. The yield of grain per acre varies from 

 10 to 25 bushels, the average probably being about 15 

 bushels. 



THE COWPEA 



The cowpea is said to be a native of India or Persia, 

 and from there to have been introduced into China at an 

 early date. It was not known in Europe until about the 

 middle of the sixteenth century. In the United States 

 it was introduced into South Carolina or Georgia early 

 in the eighteenth century. It was not of great impor- 

 tance in this country, however, until within the last few 

 decades, but now it is the most important legume of the 

 Southern States. 



318. Description. — The cowpea, Vigna unguiculata, 

 is an annual with a habit of growth varying with the 



