508 



SCIENCE 



[N. 8. Vol. XLV. No. 1169 



though there may be slight variations from 

 year to year, depending upon the season, these 

 environmental factors influence all varieties 

 alike, and the seed of the varieties that veere 

 high in percentage of oil the first year have 

 remained so during subsequent seasons. The 

 seed of the same variety when grown on the 

 sandy soil of the coastal plains produce uni- 

 formly less oil than when grown during the 

 same season on the red clay soil of the Pied- 

 mont Plateau. This difference varies from 

 0.51 gallon to 2.3 gallons per ton of seed, 

 depending upon the variety. In a general 

 way the varieties with the highest proportion 

 of meats to hulls produce the most oil; but 

 there is no positive correlation between per- 

 centage of meats and the oil content, since 

 the percentage of oil in the meats varies with 

 the variety. 



TABLE SHOWING AVERAGE RESULTS OBTAINED WITH 

 AIE-DRY SEED OF TWENTY-ONE VARIETIES OP 

 COTTON GROWN FOR THREE SUCCESSIVE 

 TEARS ON THE COLLEGE DEMON- 

 STRATION FIELD, AT ATHENS, 

 GEORGIA 



1 Nitrogen determinations made by department 

 of agricultural chemistry. 



The seed from cotton plants grown upon 

 soil to which fertilizer high in nitrogen has 

 been applied are uniformly higher in nitrogen 

 than seed from plants of the same variety 

 grown during the same season on soil not so 

 liberally supplied with this element — the 

 average difference being less than one half of 

 one per cent. The amount of nitrogen found 

 in the seed from different varieties is fairly 

 constant. In the seed of one variety only, did 

 this variation exceed twenty-three hundredths 

 of one per cent. 



The difference in the value of the cotton- 

 seed meal and the hulls, produced by a ton of 

 seed from the variety yielding the most oil and 

 the one yielding the least amount of oil was 

 only forty-four cents, and the increased 

 amount of lint on the seed of the inferior 

 variety more than offset this difference. 

 Therefore, there is practically no difference in 

 the value of cotton seed aside from oil con- 

 tent, and the greatest variation between dif- 

 ferent varieties of seed in this respect was 

 found in the season of 1914, when the per- 

 centages were 23.69 and 17.38, respectively. 

 The average variation for three years was 

 four and forty-two one hundredths per cent., 

 or eleven and eight tenths gallons of oil per 

 ton of seed. Taking the average price of seed 

 for the same three years and the average 

 yield of oil in gallons per ton of seed, it will 

 be found that the price paid for the oil they 

 contained was 82J cents per gallon. On this 

 basis there is a difference in value of seed 

 from the varieties of high and low oil content 

 shown in the above table of $9.73 per ton. 



By eliminating the inferior varieties, the 

 quality of the seed could easily be improved, 

 thereby increasing their average value $6.00 

 per ton, and the present annual crush of more 

 than five million tons would represent a sav- 

 ing of twenty-five million dollars per annum. 

 This elimination could easily be effected if the 

 seed were purchased on the basis of their oil 

 content, and these data show conclusively that 

 this is the only accurate basis of commercial 

 standardization. Loy E. Rast 



Georgia State College of Agriculture, 

 Athens, Ga. 



