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’, 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 
Near Center, Convex Full, Constricted Loosely Filled, ae 
Near Point Near Center, between Beans Crowded with Beans > 
la Near Stem - Ventral Sature 
\ SD / Vi Ss 
Bean~ 
(Back) full Long 
Cylindrical 
(} Flat 
Ends 
Rounded 
Long 
Kidney 
Broad 
Kidney 
Ends 
Rounded 
Ends 
Truncate 
Double Barrelled 
Unsymmetrical 
Point 
Long from mer Long Curved Beans, on Short, Straight Short, Curved from 
ort from ve B D 
Back Center of Pod Forward} center Line, Alternate Sides trou Back 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. 
ACCESSION No. BEAN VARIETY SOURCE 
Location of trial Section, row to row, ine, Observer Year 
OIL PREVIOUS CROP FERTILIZER USED? 
Gravelly, sandy, loamy, clayey, mucky wet dry early late well poorly fitted 
AREA , i 
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 
Fie. 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. 
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