BOTANICAL CHARACTERS 



91 



an important point for the farmer. A breed which ripens off chap. 

 too quickly after flowering will not have time to form and IV ' 

 store enough starch to produce a heavy crop of grain ; but if 

 the shortening of the time of growth takes place between 

 germination and flowering, it may, perhaps, not have such an 

 effect on the yield. The shortest period between germination 

 and flowering noted by the writer has been sixty-four days. 

 Variation in this respect may be due in part to difference in 



Fig. 38. — Silks injured by larvae. 



amount and time of rainfall. If the grain is planted early in 

 the season germination and growth are retarded because the 

 temperature of the soil is not sufficiently high. In South 

 Africa, drought in December and January sometimes checks 

 vegetative growth and hastens flowering. But soil-moisture 

 and temperature will not account for all of the differences 

 noticed. 



Within the same breed the flowering period of individuals 

 varies greatly ; the extremes noticed are fourteen and twenty- 



