194 Mortier F. Barrus 



plants throughout the season although blight was present to some extent, 

 He applied bordeaux mixture to the soil at the rate of 4320 gallons to the 

 acre. In the first crop of the year the blight was reduced one-half on 

 leaves and pods, but in the second crop there was just as much blight on 

 these plants as there was on the check. Moreover, the plants growing on 

 land that had received the application were smaller than those on the un- 

 treated soil. 



Rotation of crops 



The idea that the fungus is able to winter in the soil has led many 

 writers to recommend, among other suggestions, that the grower should 

 not plant beans on land that bore a diseased crop the previous season. 

 Harvey (1894 : 153) calls attention to this, and in the same year Cobb (1894) 

 advises a change of ground. Halsted (1900 b: 127), after growing beans 

 each year on the same ground for a number of successive years, found 

 that the plants yielded more in the first four years than when grown on 

 new land, but less afterward. Usually a greater number of spotted pods 

 were produced on plants grown year after year on the same land. 



Observations were made by the writer on beans grown as the seventh 

 successive crop on the same land. They appeared as thrifty, and yielded 

 as well, as any crop grown on rotated land. Moreover, they were as free 

 from anthracnose and blight as the others, although in fairness it must 

 be said that the summers had been dry for the three years preceding the 

 observations. There is little chance of anthracnose occurring where beans 

 are planted year after year on the same ground, if the vines, when affected, 

 are not returned to this soil. There is greater danger that such a practice 

 will introduce other diseases, especially stem rots, which tend to reduce 

 the yield materially. 



Selection of resistant plants 



As has been stated earlier in this paper (page 149), no variety of Phaseolus 

 vulgaris has been found to be absolutely immune to anthracnose, although 

 a selection of the ordinary Red Kidney has been obtained which has 

 proved to be resistant to such an extent that it will produce a very 

 satisfactory yield in years when the ordinary Red Kidney becomes badly 

 affected, and a Nova Scotia White Marrow has been located that shows 

 considerable resistance in the field although susceptible in the seedling 

 stage when inoculated artificially. Further progress in obtaining resistant 



