OATS 283 



under ordinary conditions, to plant the seed-plot. This 

 plot should be large enough to furnish seed for the general 

 crop. At the end of the second year the best plants are 

 selected from the seed-plot to plant the seed-plot of the 

 next year. The remainder of the crop from the seed-plot 

 is used to plant the general crop. This method can be 

 depended on to maintain the excellence of a variety and 

 probably to effect its slow amelioration. Rapid improve- 

 ment involves a method which gives more attention to the 

 progeny of individual plants. 



345. The isolation of elementary species. This 

 method is based upon the principle that our so-called 

 varieties of small-grain are neither pure nor uniform but 

 are made up of numerous elementary units or types which 

 are extremely variable as regards their excellence. As 

 oats are naturally self-pollinated each elementary type 

 tends to breed true from year to year. Rapid improve- 

 ment is therefore based upon the isolation of the superior 

 type from the mixture and its subsequent multiplication 

 in a pure form. The breeder goes into the field and after 

 a careful study of the individual plants or types, selects 

 a number of the best individuals. The seed from each 

 individual is kept separate, and the next year is planted 

 either in a row or "centgener" plot to itself. The supe- 

 riority of the individuals selected is determined by a care- 

 ful study of the uniformity and productiveness of their 

 progeny. The seed of each superior type that breeds 

 uniformly true is kept to itself and multiplied. This forms 

 the basis of an improved strain. The most rapid and per- 

 manent improvement of oats in the past has been accom- 

 plished by this method of individual plant selection. 



346. Impfovement by hybridization. The improve- 

 ment of oats by hybridization is rather difficult, not alone 



