Disease Resistance in Beans 9 



Practical problems 



Yield. Chief of the practical problems involved is, of course, the pro- 

 duction record. A new variety that does not yield somewhat more than 

 the average per acre of the standard sorts would not be accepted by 

 growers. The present average reflects the losses in years of disease. A 

 new variety which cannot equal the yield of the standard sorts in years 

 when there is no disease clearly has' very little to commend it. About 

 the only advantage in the use of the new variety would lie in a tendency 

 to eliminate fluctuation in yield (with attendant fluctuation in price), 

 but as compared with the general character of the growing season and 

 its effect on yield the elimination of the factor of disease might not pro- 

 duce a significant effect. At least this would be likely to be true in the 

 case of such diseases as anthracnose, where severe losses occur only at 

 intervals. In the case of a disease such as mosaic, however, the losses 

 may be so great that the crop must be abandoned altogether. This was 

 true in 1916 to 1918, in those parts of New York where Navy Pea beans 

 were grown. Mosaic became so severe that this variety could not be 

 grown. The substitution of the mosaic-immune Robust for Navy Pea 

 occurred in these areas just as rapidly as seed of the new sort could be 

 produced. In this case, however, the substitute is better than the origi- 

 nal in every respect. 



Minor objections to type of growth and the like might be easily over- 

 come if the financial return can be shown to be adequate. But a variety 

 that does not fit in readily with an established cropping system would 

 have little chance to succeed. 



Trade demand. The new variety must conform to the so-called ''de- 

 mand of the trade." While it may be true that a Bostonian housewife 

 requires the variety Yellow Eye for baking, it is equally true that the 

 demand of the average housewife rarely goes beyond a white bean or a 

 colored one. This statement is easily confirmed at any public market. 

 The demand for particular kinds of beans comes clearly from those con- 

 sumers who use very large quantities of beans for canning purposes and 

 the like, and from the dealers who must handle still larger quantities. 

 The kinds of beans that are now on the market seem to satisfy present 

 demands, and in general only the hybrid which conforms to some one of 

 these types is worth offering to the public. 



The quantity of seed now on hand is sufficient to begin comparative 

 yield tests. After one more year the stock should be large enough for 

 field tests in the various bean sections. The field tests arc necessary be- 

 cause varieties that require more than one hundred days from planting 

 date to harvest cannot receive a fair test at Ithaca, although they might 

 mature very well in one hundred days if grown in a region where the 



