I46 MAINE AGRICULTURAL EXPERIMENT STATION. I916. 



entire lot of grain. Further such immature grain will tend to 

 lower the weight per bushel and likewise the yield. 



All the plants of a pure line, since they are the descendants of 

 a single original plant, will have the inherent tendency to ripen 

 at the same time. This is one of the factors which leads to 

 increased yields with pure line varieties. Of course, environ- 

 mental conditions may greatly influence the time of ripening so 

 that unless a field is reasonably uniform in the character of its 

 soil there will always be some difference in maturity in differ- 

 ent parts of the field. However, insofar as this matter can ^e 

 remedied by seed, the pure line varieties offer a distinct advan- 

 tage over the ordinary commercial varieties. 



It is planned to continue the majority of these pure lines in 

 our test plots until such time as newer and better lines shall be 

 obtained. A large number of new selections are being tested 

 at the present time. These will be tested along with the best 

 of the pure lines described in this bulletin and also with a 

 selected list of commercial varieties. 



In order that these pure lines may be tested by the farmers 

 of the state, arrangements have been made with the Extension 

 Department of the College of Agriculture to place the limited 

 amount of seed of each line in the hands of representative 

 farmers. The arrangements are that the farmer shall grow one. 

 of these lines for at least two years in order to give it a satis- 

 factory test. Seed from these lines which prove satisfactory in 

 their respective communities is to be offered for sale at a rea- 

 sonable price. It is hoped that this arrangement will secure a 

 distribution of the seed of such of these pure lines as prove 

 themselves worthy. Maine 340 will continue to be grown as a 

 farm oat at Highmoor and the surplus seed offered for distri- 

 bution. 



Summary. 



In the introduction to this bulletin the meaning of a pure 

 line is defined and illustrated. The general methoas used in 

 the pure line breeding of cereals are also discussed. 



The work with which this paper deals was begun in 1910. in 

 that year 460 individual oat plants were selected from 18 differ- 

 ent commercial varieties. In 191 1 seed from 188 of these 

 plants was grown in short garden rows. 



