Department of Experimental Plant-Breeding. 25 



coarse stems, fine stems, early bloom,' late bloom, and the like. Plants 

 grown from open fertilized seed of these various selections were 

 planted in the field in 1905 ; of these, 147 plats of 32 plants each were 

 grown, making- a total of 4,704 plants. 



In the summer of 1907, a careful study was made of all of the plants 

 and over 200 selections were made, representing many different types. 

 In the fall of the same year, trial plats were planted from each of 

 these selections and these plats are now showing very interesting- 

 developments. 



Each year since the beginning of the experiment, records have been 

 made of the height, duration of bloom, season of maturing, yield, etc., 

 of each plant, so that important data is available to serve as a guide 

 in making the selection of the plants which are most likely to prove 

 valuable as foundation stocks of improved races. 



The methods of improving timothy have never been worked out. 

 and the first and most important part of the work has thus been to 

 determine the best methods of breeding this crop. Careful studies 

 of the progenies of select plants planted in 1905 have shown conclu- 

 sively that open-fertilized plants are very variable. It is probable that 

 this great variability is due mainly to the cross-fertilization of dififer- 

 ent types, or so-called biotypes, many of which are found to exist in 

 timothy. It would thus seem necessary, if different types are to be 

 bred into stable races, that the select plants be inbred or that the 

 progeny be isolated and the results of crossing be slowly weeded out 

 by continuous selection, which would take a number of generations. 

 Experiments which have been recorded in literature up to the present 

 time, indicate that timothy is a strictly cross-fertilized plant and will 

 not set seed by self-fertilization. The writer took charge of these 

 experiments too late in 1907 to make extended experiments to de- 

 termine this point, as all of the plants were past the regular blooming 

 period. A number of belated heads, however, were inclosed in bags, 

 and practically all of these set some seed, which proved to be of as 

 good vitality and vigor as cross-fertilized seed. Further extended ex- 

 periments made in the spring and .summer of 1908 have shown that 

 self-fertilized seed can be secured from practically all plants but that 

 there is apparently a considerable degree of difference in the capacity 

 of different plants to set seed by self-fertilization. Sufficient seed has 

 been secured in practically all cases for experimental purposes, and 

 the fixation of strains by inbreeding would thus seem to be the prac- 

 tical method of work. 



Timothy variations. — Connected with the timothy work, one of the 



