BREEDING OF VEGETABLES 253 



"By following the proper methods any skillful cabbage grower 

 who has Fusarium sick soil may either undertake with reason- 

 able confidence to develop a resistant strain of his own, or having 

 secured one of these resistant strains he can maintain its resistance 

 and produce his own seed." 



ASPARAGUS 



Asparagus (Asparagus officinalis) is dioecious in habit of flow- 

 ering altho hermaphrodite plants have been discovered (Norton, 

 1911-1912). With this vegetable, cross-pollination is usually 

 necessary for seed production. 



Rust-Resistant Asparagus. The fungus, Puccinia asparagi, 

 has occasioned a great deal of alarm among commercial asparagus 

 growers, particularly those of the eastern United States. This 

 rust differs from that occurring on the small grains in that all 

 stages of the rust occur on the asparagus plant. At the invita- 

 tion of Massachusetts growers, the United States Department of 

 Agriculture in cooperation with the Massachusetts Agricultural 

 Experiment Station undertook to produce a resistant variety. 

 Norton (1911-1912, 1913) has reported on this investigation. 

 Because of the dioecious habit of asparagus it was necessary to 

 select two kinds of plants male and female. Selections were 

 based on rust resistance, i.e., only plants which showed a high 

 degree of resistance were chosen. In 1909 the first test of the 

 transmission of relative rust resistance was made. Twelve lots 

 saved from as many plants showing various degrees of rust re- 

 sistance were planted in duplicate in short rows. After the 

 young shoots appeared they were dusted several times with fresh 

 uredospores. Later in the season observations were made on 

 the degree of infection. The results are given in Table LXV 

 (Norton, 1913). 



Table LXV shows clearly that rust resistance is inherited. 

 Various artificial crosses were made between forms showing rust 

 resistance. The progeny of some of these crosses proved highly 

 resistant and in some cases were more resistant than the parents. 

 By this method several strains of asparagus with a high degree of 

 resistance have been produced. In the production of a new form 

 a male plant obtained in 1910 from a lot of New American of un- 

 known origin proved of marked ability in transmitting vigor and 

 rust resistance to the progeny. The female plants known as 

 Mary and' Martha were selected from the variety Reading 



