GRASSES, CLOVER, AND ALFALFA 



213 



Cornell. Individual plant selections are vegetatively propa- 

 gated in plots isolated as much as possible. Seeds produced by 

 the better clones are planted in varietal plots for comparison. 

 The best commercial varieties are also grown for comparison. 

 When a new variety proves superior and has practical uniformity, 

 it is increased and distributed on a large scale. A comparison 

 of ordinary timothy and two improved forms distributed by the 

 Svalof Station is shown in Table LII (Witte, 1919). 



TABLE LII. YIELD OF DIFFERENT VARIETIES OF TIMOTHY IN TRIALS AT 

 SVALOF, 1909-1918 



Timothy, like many other grasses, is susceptible to a rust 

 (Puccinia graminis). It has already been mentioned that in 

 making selections at the Cornell Station some attention was 

 given to resistance to this fungus. Eleven of the better Cornell 

 selections have been tested for rust resistance (Hayes and 

 Stakman, 1919). The relation of other characters to resistance 

 was also studied. The rust classes are; 1, no rust; 2, slight in- 

 fection; 3, moderate infection: and 4, heavily rusted. Average 

 erectness is taken with 1 as a basis of an erect plant and 10 a 

 procumbent one. Table LIII presents the data. 



From the table it is apparent that the Cornell selections 

 possess a high degree of resistance. Relatively few plants are 

 found in rust classes 3 and 4. The Minnesota selections show the 

 reverse condition, i.e., most of the plants are found in classes 3 

 and 4. These facts show that a variety of rust-resistant timothy 

 may be isolated. 



Timothy breeding may be briefly summarized as follows: 



1. Individual plants propagated vegetatively in rows. Bulb- 

 lets are placed far enough apart in the row to give ample room 

 for individual development. 



2. The clones produced in 1 are closely inbred or seed is 

 saved from vegetatively multiplied plants in isolated plots. By 



