292 BREEDING CROP PLANTS 



First Year. (a) Remove from the part of the field used for 

 saving tubers all plants which show evidences of diseases. This 

 should be done during the growing season. 



(b) At harvest time dig at least 100 hills by hand, keeping 

 each hill separate. 



(c) Use tubers from a number of the better hills for the stock 

 plot the following year. 



Second Year. Method I. Plant all good tubers from previous 

 year's selection of best hills in a bulk seed plot. Enough tubers 

 should be used to plant about Y acre. This requires approxi- 

 mately 5 bushels, which allows some tubers to be discarded. 



Method II. This is the hill-to-row method. In order to 

 compare the productive capacity of each selected hill it is desir- 

 able to have each row the same length and planted from the 

 same total weight of potatoes. All of the progeny of some hills 

 will be discarded this second year. Those that give a good yield 

 and are desirable in other ways may be further tested. 



Third Year. Method I. Continue the stock plot by the same 

 means as used in Method I for the second year's work, and use all 

 good tubers produced each year in this seed plot for field planting. 

 This work may be continued each succeeding season by the same 

 plan. 



Method II. Make a further test of the best selections as 

 determined by the second year's test, growing much longer rows, 

 thus obtaining more reliable results. All tubers free from disease, 

 of the best yielding strain or strains, may be used to increase 

 the stock the following year. 



The essential features of these two methods are presented on 

 page 291 in diagrammatical form. Method II probably is 

 somewhat better if all details of the test are carefully performed. 

 For the average farmer, Method I is less cumbersome and if 

 constantly practiced would probably give about as good a result 

 as Method II. 



IMPROVEMENT BY SELECTION OF SUCH CROPS AS ALFALFA, 

 CLOVER, AND GRASSES 



Obtain, if possible, a variety which is especially adapted to the 

 conditions. Breeding work should aim at producing a variety 

 which excels in resistance to winter injury and to plant diseases 

 and is also a high producer of hay and seed. 



