SOYBEANS 533 



dry when placed in storage or else placed where good 

 ventilation is afforded and the seed not bulked together 

 in large quantities. Under whatever conditions the seed 

 may be stored, it should be examined occasionally to detect 

 any tendency to heat. If signs of heating are found, the 

 seed should be removed at once and spread out until per- 

 fectly dry. 



649. Pollination. The soybean flower is completely 

 self-fertile, bagged plants setting pods as perfectly as those 

 exposed. The flowers are much visited by bees, which 

 seek principally the pollen, as the soybean flower secretes 

 but little nectar. Pollination occurs even before the flower 

 opens, but nevertheless occasional cross-pollinations occur 

 where different varieties are grown in close proximity. 

 Such natural hybrids can often be detected by the fact 

 that the seeds of heterozygote plants present queer combi- 

 nations of color, such as smoky green, smoky yellow, 

 brown, and yellow and black banded. In the course of 

 varietal trials at Arlington Farm, Virginia, extending over 

 five years, many such natural hybrids were secured, and 

 similar crosses occurred at the Kansas Experiment 

 Station. 



650. Seed yield. With regard to the seed yield of the 

 soybean, there is considerable variation in the figures 

 given. When grown alone for seed, the best varieties 

 under proper culture yield from 30 to 40 bushels of seed 

 to the acre. A maximum yield of 50 bushels to the acre 

 has been reported from North Carolina. According to 

 various authorities, the yields in Manchuria range from 

 about 1000 pounds to the acre on very poor soil up to about 

 1800 pounds to the acre on good soil. 



In the United States, yields have been reported by 

 various investigators as follows : - 



