48 APPLICATION OF PRINCIPLES OF HEREDITY TO BREEDING. 



in those sections where the rainfall was 22 inches or more the pre- 

 vailing variety was another club wheat known as Little Club." 



The growers of Red Chaff gave as their reasons for using this 

 variety that it stood up better than Bluestem and yielded more 

 than Little Club, while the growers of Little Club stated that this 

 was the only variety they had ever found that would stand up and 

 hold its grain under their conditions. 



It happens that all three of these varieties are spring wheats, 

 but long experience has shown that sowing them in the fall would, 

 in favorable seasons, produce yields 30 to 60 per cent greater than 

 spring sowing. Hence, all three varieties were generally sown in the 

 fall, but they would frequently freeze out to a greater or lesser ex- 

 tent. There was therefore an insistent demand for winter wheat. 

 The writer had collected from various parts of the world an exten- 

 sive series of winter wheat varieties, and in 1899 a large number of 

 these varieties had been grown for five years. Many of them were 

 perfectly hardy and made enormous yields in favorable seasons, 

 but they were inclined to straw-fall and to shatter their grain as soon 

 as they were ripe; so that it did not seem advisable to recommend 

 any of them to the farmers. 



At that time Mendelian principles were unknown in this country 

 and had been forgotten in Europe, so that the writer had intuition 

 alone to guide him in his attempts to produce a variety of wheat 

 adapted to local conditions. By chance these intuitions proved to 

 be correct and led to the discovery of the law of recombination pre- 

 viously stated. Fortunately, the work proceeded from the beginning 

 just as it would have done had the writer had full knowledge of the 

 law of recombination, for the law was discovered in time to use it as 

 soon as it could have been used in this work. 



Eleven of the best yielding winter varieties were crossed with the 

 Little Club and the Red Chaff varieties (the Bluestem could not be 

 successfully grown at Pullman, where the rainfall was about 22 

 inches). Among the first-generation hybrids there were, therefore, 

 eleven kinds. The seed of each hybrid plant was saved separately, 

 so that the next year we had as many plots as we had hybrid plants 

 the year before. 



The object of this hybridization work was to combine the winter 

 hardiness of one class of varieties with the stiff straw and the tightly 

 closed chaff of the other varieties. We now understand why this 

 combination succeeded in every one of the crosses, so that from 

 each of them resulted new and fixed varieties of wheat combining 

 the characteristics mentioned. As was to be expected, some of the 

 new varieties proved to be much more productive than others. . 



165 



