FALL SOWING 217 



lay down a definite rule covering the time of fall 

 sowing. The dry-farmers in such places usually 

 sow at any convenient time in the hope that an early 

 rain will start the process of germination and growth. 

 In other cases planting is delayed until the arrival 

 of the first fall rain. This is an uncertain and usually 

 unsatisfactory practice, since it often happens that 

 the sowing is dela3'^ed until too late in the fall for the 

 best results. 



In districts of dry late summer and fall, the great- 

 est danger in depending upon the fall rains for ger- 

 mination lies in the fact that the precipitation is 

 often so small that it initiates germination without 

 being sufficient to complete it. This means that 

 when the seed is well started in germination, the 

 moisture gives out. When another slight rain comes 

 a little later, germination is again started and pos- 

 sibly again stopped. In some seasons this may occur 

 several times, to the permanent injury of the crop. 

 Dry-farmers try to provide against this danger by 

 using an unusually large amount of seed, assuming 

 that a certain amount will fail to come up because 

 of the repeated partial germinations. A number of 

 investigators have demonstrated that a seed may 

 start to germinate, then be dried, and again be started 

 to germinate several times in succession without 

 wholly destroying the vitality of the seed. Nowoc- 

 zek has conducted a number of experiments on this 

 subject, with the following results: — 



