518 FORAGE PLANTS AND THEIR CULTURE 



under Florida conditions, soybeans seldom grow normally c 

 In southern Louisiana it is a common phenomenon for 

 the Mammoth soybean to make a satisfactory growth, 

 but the pods do not fill. Some very late varieties tested 

 at Arlington Farm, Virginia, failed to bloom when killed 

 by frost at the end of 150 days. Such varieties were 

 mainly from the highlands of northern India, where a 

 much longer growing season occurs. 



Soybeans will withstand considerable frost, both when 

 young and old. Some varieties will in the fall withstand 

 temperatures as low as 27 Fahrenheit without serious 

 injury to the leaves. If the pods are fairly well filled 

 before a killing frost occurs, they will usually ripen 

 satisfactorily. 



631. Importance. The soybean has been slowly but 

 steadily increasing in importance in America during the 

 past 20 years. Its relative importance is less than that 

 of either the field pea or the cowpea. 



632. Desirable characters in soybean varieties. As 

 the number of soybean varieties is very large, and as new 

 sorts are easily secured by crossing, the most desirable 

 characters, both for forage and for seed-production, need 

 to be considered. In this crop as in others, yield is the 

 most important single desideratum. Secondary consider- 

 ations are habit, coarseness, ability to hold leaves, color 

 of seed and ease of shattering. 



An ideal variety for forage should be erect; tall, so that 

 the pods are not too near the ground ; slender, but without 

 tendency to lodge, so as to permit easy mowing; leafy 

 and with the ability to retain the leaves late; yellow- 

 seeded, as hogs will find such seeds as are shattered more 

 readily ; non-shattering, a character more common in 

 small-seeded than in larger-seeded varieties; disease 



