16 THE SOY BEAN ; HISTORY, VARIETIES;, AND FIELD STUDIES. 



Chernie, Jet, and Meyer extremely sensitive. The comparative 

 resistance of the varieties is reported as follows, the first being least 

 injured: (1) Ogemaw; (2) Haberlandt, Ito San, Kingston, Guelph; 

 (3) Habaro, Shingto, Manhattan, Brindle; (4) Jet; (5) Meyer, 

 Chernie. 



It may be that the same variety varies in frost resistance, depend- 

 ing on its stage of maturity. In the foregoing list, however, the 

 Ogemaw, though very early, usually matures with the Manhattan 

 and the Chernie, while the Haberlandt is fifteen days later. 



PERIOD OF MATURITY. 



In soy beans there is a continuous succession of varieties from very 

 early to very late. With very few exceptions, earliness is correlated 

 with size, the largest varieties being latest. As in the cowpea, early 

 plantings take a longer time to mature than late plantings, but there 

 is by no means a consistent behavior in the different varieties in this 

 respect. In general, the later the variety the more is its life period 

 shortened by later planting. 



Haberlandt, in 1877, planted one variety at Vienna at intervals of 

 one week through the season and attempted to correlate the life 

 periods obtained with the amount of heat. His results are shown in 

 Table I. 



Table I. — Results of planting a single variety of soy bean at different dates, Vienna, 



Austria, 1877. 



Date of planting. 



March 31 . 

 April?.. 

 April 14.. 

 April 21 . . 

 April 28.. 

 May 5.. . 

 May 12.. 

 May 19.. 

 May 26.. 

 June 2... 

 June 9... 



Date of harvest. 



September 29 . 



do 



do 



do 



do 



October 15 



do 



October 18.... 



do 



do 



October 26..., 



Life 

 period. 



Days. 

 182 

 175 

 167 

 160 

 153 

 163 

 156 

 152 

 145 

 138 

 139 



Total heat required- 



Until 

 germina- 

 tion. 



C. 

 230 

 294 

 189 

 217 

 228 

 209 

 221 

 275 

 153 

 152 

 130 



Until 

 blossom- 

 ing. 



° C. 

 1,185 

 1,102 



008 

 026 

 995 

 936 

 960 

 1,043 

 985 

 871 

 739 



Until 

 maturity 



C. 



2,972 



2,893 



2,787 



2,753 



2,701 



2,811 



2,722 



2,641 



2,519 



2,405 



2,322 



J 97 



