1028 Walter H. Burkholder 



From the foregoing observations on the character of Fusarium martii 

 phaseoli, it appears highly improbable that the dry root-rot of beans 

 can be entirely eliminated by longer crop rotations. 



SOIL TREATMENT 



The application of chemicals and fertilizers to the soil to destroy or 

 hold in check soil pathogenes, has seldom proved successful on an exten- 

 sive scale. In seedbeds and greenhouses where expense does not pro- 

 hibit, treatment with formaldehyde may be used profitably. A formal- 

 dehyde solution applied in the furrow with the seed at the time of sowing 

 has proved effective in the control of onion smut. On the other hand, 

 the appli cation of fertilizers has tended at times to lessen the effect of 

 certain root diseases. Such has been the case in liming fields contami- 

 nated with the organism causing clubroot of cabbage. Acid phosphate 

 applied to tobacco fields also has proved to be beneficial in holding in 

 check the black root-rot. 



During the season of 1915 a number of farmers near Perry and War- 

 saw, New York, under the direction of the Wyoming Coimty Farm 

 Bureau tried varying applications of lime and acid phosphate on their 

 bean fields. Four of the farms were visited by the writer with H. M. 

 Bowen, the County Agent, and careful observations were made. In no 

 instance could it be determined that the fertilizers checked the disease 

 to any extent. Similar reports were received from various other farms. 



The application of toxic substances to the soil, especially non-volatile 

 substances, must be made with great care. The roots of the plants are 

 extremely sensitive and in the seedling stage great injury may be done 

 to them. The pathogene, too, s frequently veiy resistant to chemicals 

 and cannot be destroyed easily. Furthermore the after effects of treat- 

 ment with various chemicals have been reported to be injurious to other 

 crops grown in rotation. Sherbakoff (1915 a) has shown this to be true 

 for clover when sulfur was applied previously; and Wheeler, Hart well, 

 and Moore (1899) have shown the same thing to be true for cereals. 



However, regardless of the fact that clover generally occurs in the 

 rotation with beans, a preliminary test was made with sulfur in the sum- 

 mer of 1915. Sulfur was drilled in with the seed at the rates of 200 

 pounds and 400 pounds to the acre. In neither case was the germina- 



