i6o Bulletin 251. 



parently represent good plants and plant the product of each head or 

 ear in a row by itself, the same as is described for planting the individual 

 plants, except that where heads only are selected there \\ill not be seed 

 enough for a 17- foot row. In this case the rows will have to be made 

 short in accordance with the amount of seed in the head selected. Ordi- 

 narily these will furnish enough seed for one or two 17-foot rows the 

 next generation. The further tests should be carried out exactly as de- 

 scribed above where whole plants are selected. 



Systciiwtic selection of JiigJi-yielding varieties. 



Another line of work similar to the above and which should be carried 

 out in the different years in exactly the same way, is the selection of w^ell- 

 known races to secure high-yielding strains. If the farmer is growing a 

 standard variety which he has thoroughly tested on his farm and which 

 he knows to be well adapted to the local conditions, he may be able to 

 secure a higher-yielding strain by selecting and testing the highest yield- 

 ing plants. To carry out this work go through a field of the variety 

 just before cutting and select out a number of the best-yielding plants. 

 These should be harvested and the product of each plant preserved 

 separately and planted the next year by the plant-to-row method. Carry 

 out the test of these plants through several years exactly as described above 

 for the selection of chance variations and sports. 



Selection of large heads of .wheat. 



As explained in the early part of this paper, in general the individual 

 is the unit of selection which should be followed. There is, however, 

 considerable evidence to show that nuicli improvement may be accom- 

 plished by the simple selection of large heads. 



The simplest application of this method consists in examining a 

 field of a good standard variety and selecting a quantity of the largest 

 heads. To start this work well, enough heads should be selected to make 

 at least a bushel or more of seed. Thresh this seed together and plant it 

 in a good field the next year in an increase-plot. This if seeded fairly 

 lightly will give a field of an acre or more. 



When this increase-plot is ri])e go over it again and select out enough 

 large heads for a similar sized plot the third year. Harvest the remainder 

 of the crop together and use the seed to plant the general crop of 

 the third year. Tliis method of selection should be continued year after 

 year as a regular way of getting good seed for planting. This policy 

 has been followed extensively in Canada and is reported as giving very 

 satisfactorv results. 



