134 



MORTIER F. BARRUS 



TABLE 3 (continued) 



April 13 may not have given infected plants because the surface of the 

 soil had been allowed to remain dry for some time through neglect. As 

 no new spores had been produced to vitiate the experiment, these, pots 

 were replanted on May 7. 



It would appear from this experiment that a few spores are able to 

 live over winter in the soil outdoors and bring about infection the following 

 spring. It is but fair to say, however, that the plants were not in any 

 case screened from greenhouse insects that were present, and that other 

 inoculation experiments with bean anthracnose were being conducted 

 by other persons in another compartment of the same house and in 

 adjoining houses. This may account for the few cases of disease occurring 

 in the spring experiments. The infection is very light compared with 

 that occurring on plants grown in freshly inoculated soil. Under practical 

 bean-growing conditions the chances of infection from this source must 

 be negligible. 



An experiment similar to the one recorded above was tried the following 

 winter, the same methods being employed. A greater effort was made, 

 however, to keep the surface of the soil moist at all times, and also 

 unsterilized but presumably uncontaminated soil, as well as sterilized 

 soil, was used. On January 5, 1918, all the pots were well moistened with 

 tap water, soon after which a suspension of spores was poured over the 



