236 



Journal of Agricultural Research 



Vol. III. No. 3 



OIL CONTENT AS AFFECTED BY LENGTH OF GROWING PERIOD 



Independently of any differences between early and late varieties as 

 such, it might be expected that difference in oil content would be influ- 

 enced by both the character and the length of the growing period. Sev- 

 eral investigators have concluded that the length of the growing period 

 is an important factor in determining the starch and protein content of 

 wheat. In plants of determinate growth, in which all the seed are 

 developed during approximately the same period, the effect of the length 

 of the growing period on the oil content may be studied b}- making 

 successive plantings at given intervals, since many of such species show 

 a marked tendency to shorten the growing period when planted abnor- 

 mally late. Mooers (1909) has called attention to this tendency in soy 

 beans, and the present authors have determined the oil content in the 

 seed of several varieties of this crop planted at stated inter\'als during 

 the spring and summer months.' The results of the tests are shown in 

 part in Table VI. 



Table \'l. — Oil content of soy beans planted at intervals of t-uo -ueeks in IQII 



Variety and date of plaut- 

 ing. 



S. P. I. No. 21755: 



May I 



May 15 



June I 



June 15 



July I ■ 



Haberlandt (S. P. I. 



No. 17271); 



May I 



May 15 



June I 



June 15 



July I 



Buckshot (S. P. I. 



No. 17251); 



May I 



May 15 



June I 



June 15 



July I 



Medium Yellow (S. P. 

 I. No. 17269): 



May I 



May 15 



June I 



June 15 



July I 



Numberof 



days from 

 planting 

 to bloom- 

 ing. 



40 

 35 

 37 

 32 

 27 



61 



54 

 50 

 45 

 44 



40 

 40 

 39 

 39 



56 

 49 

 50 

 45 

 41 



Nmnberof 

 days from 

 blooming 



to full 

 maturity. 



62 



58 

 50 

 54 

 58 



83 

 76 



74 



74 



72 

 69 

 68 

 58 

 64 



102 

 94 

 77 

 .73 

 66 



Nimiberof 



days from 



planting 



to full 



maturity. 



93 

 8- 

 86 



144 



130 

 124 



119 

 116 



112 



109 



107 



97 



97 



158 

 143 

 127 

 118 

 107 



Weight 



of 1. 000 

 beans. 



186 



153 

 166 



145 

 168 



2IO 



211 



240 

 244 



271 

 272 

 277 

 250 

 294 



329 

 313 

 312 



30s 



334 



^foisture 

 in beans. 



Per cent. 

 6. 90 



7-05 



6. 90 



7. 10 

 . 7. 60 



6.65 



6. 70 



6.35 

 6.80 



7. 20 



6. 40 

 6. 40 

 6. 20 

 6. 10 

 6. 40 



6-45 

 6.25 



5-70 

 5.80 

 6.30 



Oil in 

 beans. 



Per cent. 



17-25 

 16.38 

 17. 40 

 17.27 

 15- 51 



19- 73 

 19.47 

 20. 32 

 18.95 

 17-35 



19- 15 

 19. 62 



19-35 

 18.95 



18.43 



17. 60 



18. 25 

 17-75 

 17-38 

 i6-43 



oil in 



1. 000 

 beans. 



Gni. 

 32-4 



25-1 

 28.9 

 25.0 

 26. I 



41.4 

 41. 1 

 44. I 

 45-5 

 42-3 



51-9 



53-4 

 53-6 



47-4 

 54- 2 



57-9 

 57- I 

 55-4 

 53-0 

 54-9 



* In these experiments the authors are indebted to the Office of Forage-Crop Investigations, of the Bureau 

 of Plant Industry, for samples of the soy beans which were grown at the Arlington Experiment Farm. 

 Va., together with the data as to time of plaating and date of maturity . 



