PLANT-BREEDING METHODS 



427 



adapted for more northern localities. It has been found, as would be 

 expected, that in breeding for numerous characters at the same time the 

 recombinations in F z following hybridization of many select strains are 

 so complicated as to render very illusory the idea of reaching definite 

 results by theoretical calculations. But in spite of this difficulty hybridi- 

 zation offers a means of creating new forms which cannot be obtained 



Pod Concave 



Hear Center, Convex Full, Constricted 



Near Point Near Center, between Beam 

 Near Stem 



Loosely Filled. n,. 



Crowded with Beam 



Ventr,! Snture 

 (Back)Kull 



ouble Barrelled 



Unsymmctrical 



J Point 



Beans, on 1^ Short, Straight Short, Curved from 

 1 Center Line, Alternate Sldei **%$$* Center of Pod 

 Outline Drawing. Check outlines which best illustrate the general form and character of pod and 

 also those showing the characteristics of the beans and their arrangement in the pod- 



Point 



Long from XV Long Curved 

 Back Short from Forward 



Center of Pod 



ACCESSION No. 



BEAN 



VARIETY 



Location of trial 



Section, row to row, inc. 



SOIL PREVIOUS CROP FEBTILIZER USED? 



Gravelly, sandy, loamy, clayey, mucky wet dry early late well poorly fitted 



AREA 



feet of row 



plants to yard feet between rows 



samples In trial 



CULTURE 



from seed in place Cultivation frequent deep thorough Plants sprayed times with? 



WEATHER CONDITIONS INSECT INJURY DISEASE DEVELOPMENT OF PLANTS 

 hot cold dry wet much little none much little none good fair poor 



FIG. 174. Reverse of description blank shown in Fig. 173. 



otherwise. Thus it is an indispensable supplement to the methods of 

 selection and strain-testing. 



Variety Tests. The principal purposes of variety testing are first, 

 establishment of varietal types of field crops and vegetable plants, and 

 second, determination of the best varieties for a given locality. In the 

 establishment of varietal types many difficulties are encountered of 

 which we shall consider four. 



