8 



certain conditions that arise in the silo the crude protein is converted 

 into indigestible or insoluble nitrogenous compounds. The cowpea 

 or clover ensilage is then valuable only for the carbohydrates that it 

 contains, and either corn or sorghum is far superior to it. 



HARVESTING THE SEED. 



The majority of farmers harvest only enough seed of cowpeas to 

 plant again the next season. The ripe pods are picked by hand and 

 are stored in barrels until needed or are thrashed out by machine or 

 with flails on the barn floor during the winter. Sometimes, if the 

 crop is heavj^ enough to render it profitable, the vines are run through 

 an ordinary thrashing machine from which the concaves and alternate 

 teeth of the cylinder have been removed. But a machine breaks and 

 bruises more of the seed than when the pods are first picked off by 

 hand. Fully 95 per cent of the seed jplaced upon the market is 

 hand picked. The yield per acre varies according to the varieties and 

 the method of cultivation. Eight to twelve bushels is a fair average 

 of the amount that can be obtained when the peas are planted in the 

 corn rows. Sown alone, broadcast or in drills, yields of from twenty 

 to thirty-five and even, in rare cases, fifty l>ushels are obtained. The 

 Black, Unknown, Red Ripper, Clay, and Calico varieties are all heavj^ 

 seed bearers. Lady and White Crowder are good for table use and also 

 yield well. The Black-eyed,- Red Crowder, and AVhip-poor-will or 

 Speckled are very widely cultivated and find ready sale. Those which 

 make the largest growth of vines for green manure, as a winter soil 

 mulch, for hay or soiling are the Unknown, Red Ripper, Southdown, 

 and Claj-. Whip-ijoor-will, Black-eyed, White, and Red Crowder 

 ripen in from twelve to fourteen weeks, and hence are adaj)ted to 

 cultivation farther noi-th than the very late, but ranker growing, 

 Unknown, Wonderful, Red Ripi^er, Black, and Gourd varieties. The 

 New Era and Lee ripen seed in from six to seven weeks, and hence are 

 the ones to recommend for summer-soiling crox)S in the upper prairie 

 region of the Mississippi Valley or anywhere else that an earlj'- matur- 

 ing cowpea is required. This is one of the species of cultivated plants 

 which is very readily modified by change of habitat. Early and late 

 maturing forms may be found of every strain that has been in culti- 

 vation for any considerable time. 



THE FEEDING VALUE OF COWPEAS. 



The feeding value of cowpea vines is very high, as shown by both 

 feeding tests and chemical analyses. As hay the vines are more val- 

 uable than fed green for soiling purposes. A comparison with red 

 clover and alfalfa is made in the table on the next page, a compila- 

 tion ^ of the averages of a number of analyses from various sources. 



1 Handbook of Experiment Station Work, Appendix, 1893. 



