Dec. 15. 1914 



Oil Content of Seeds and Nutrition of Plant 



237 



The different plantings of soy beans show marked variations in the size 

 of the beans and in their oil content, but there is no definite relationship 

 between these characters and the date of planting. In other words, the 

 character rather than the length of the season in which the seed is devel- 

 oped seems to be the important factor. The seed from the latest plant- 

 ings contain a somewhat lower percentage of oil than the others, but 

 this relationship is not verified in other tests which have been omitted 

 from Table VI for the sake of brevity. These additional data all show 

 lack of definite relationship between size and oil content of the seed and 

 the length of the growing period. There is a remarkable difference 

 between varieties as to the shortening of the period required for maturing 

 seed when planted late, as illustrated by the Buckshot and the Medium 

 Yellow varieties. 



VARIETAL DIFFERENCES IN OIL CONTENT OF THE SEED 



As a preliminary to the study of oil content as affected by nutrition, it 

 was necessary to ascertain the relation of heredity to the quantity of oil 

 produced in the seed in so far as relates to the comparative behavior of 

 different varieties. This work has been limited largely to soy beans and 

 cotton, since collections of varieties of the other oil-producing plants inves- 

 tigated have not been available. 



The method of procedure has been to grow a number of varieties of 

 each species under uniform conditions, to use the purest seed obtainable, 

 and to repeat the tests for several seasons, using the precautions which 

 have been discussed above in drawing samples for analysis. In Table 

 VII are given the results obtained from material furnished by the Office 

 of Forage-Crop Investigations, representing seven varieties of soy beans 

 grown at the Arlington Experiment Farm in 1907, 1908, and 1910. 



Table VII. — Varietal differences in the oil content of soy beans grown at Arlington 

 Experiment Farm, Va., in igoj, igo8, and igio. 



Variety and year grown. 



Shanghai (S. P. 



1907 



1908 , 



igio 



I. No. 14952): 



Average. 



Eda(S. P. I. No. 17257): 



'9°7 



igo8. ,. ; 



1910 



Average. 



Weight of 

 1,000 beans. 



Cm- 

 215-4 

 186. I 

 217. I 



206. 2 



280.6 

 263.4 

 269.4 



Moisture in 

 beans. 



Per cent' 

 6.65 

 6. 16 

 6.80 



6-54 



6.30 

 6. 17 

 6- 15 



6. 21 



Oil in moist 

 beans. 



Per cent. 

 19- 55 

 18.37 

 20. 20 



19-37 



19.70 

 19.90 



21-55 



20.38 



Oil in 1,000 

 beans. 



Gm. 



42. 1 

 34-2 



43-8 



40. o 



53- 5 

 52-3 

 ;8. 2 



54-7 



