The Forward Movement in Plant-Breeding 313 



many plants have been imported from all over the world 

 which have formed rich material for the plant-breeder to 

 take and improve, and many other varieties have been 

 introduced which have immediately become valuable 

 without further improvement. Such plants as durum 

 wheat, Japanese kinshu rice, Swedish select oats, Wash- 

 ington navel orange, cold-resistant varieties of alfalfa, 

 Russian apples, varieties of dates for Southern Cali- 

 fornia and Arizona, drought-resistant olives, Egyptian 

 cotton, and very many others have added millions to our 

 agricultural wealth. 



The work of Orton and his associates in breeding plants 

 resistant to disease forms an important chapter in this 

 work. They have been successful in waging war on wilt 

 of cotton, cowpeas, watermelons (see Figs. 55 and 56), and 

 other crops by means of breeding to obtain wilt-resistant 

 strains. The only successful method of combating certain 

 maladies seems to be in this way. Strains of disease-resist- 

 ant asparagus and of rust-resistant cereals have reached 

 economic importance. 



Many great sections of the United States which are 

 now nearly barren could be made productive if varieties 

 of plants could be developed which are resistant to drought 

 and alkali. This work has occupied the attention of a 

 large corps of plant-breeders and not without results. 

 The experts from eighteen state experiment stations be- 

 sides the men from Washington are engaged in this work. 

 As a result, varieties of wheat and other cereals, alfalfa, 

 nuts, olives, and various fruits have been developed which 

 will grow in parts of this great region and are of considerable 

 economic importance. 



