1030 Walter H. Burkholder 



were noted. In all plots, including the check, the proportion of healthy- 

 plants did not exceed 5 per cent. 



Similar experiments were conducted in 1918 with the commercial 

 preparation cyanamid. Three plots, each 20 feet long and 12 feet wide, 

 were treated with varying amounts of the chemical, and a plot of similar 

 size was used as a check. Plot 1 was treated at the rate of 50 pounds 

 to the acre, plot 2 at 75 pounds to the acre, and plot 3 at 100 pounds 

 to the acre. The applications were made at the time of planting, which 

 was August 10, and the chemical was drilled in the rows. The variety 

 of beans used was Well's Red Kidney. This method of treatment injured 

 the germination considerably and retarded the growth of the plants to 

 a severe extent. The experimental plots were examined on October 3. 

 Over 90 per cent of the plants in the treated plots showed severe 

 infection of the dry root-rot. No distinction could be made between 

 these and the plants in the check plot. The results do not warrant 

 further experiments with cyanamid. 



USE OF BEANS RESISTANT TO ROOT-ROT 



Very little progress has been made in controlling plant diseases caused 

 by soil-inhabiting fungi, except by the selection and development of 

 disease-resistant strains. This is especially true when the pathogene 

 concerned belongs to the genus Fusarium. Orton (1908) has used this 

 method in checking the wilt of cotton, cowpea, and watermelon. Bolley 

 (1903), and more recently Tisdale (1917b), have selected wilt-resistant 

 varieties of flax'. Jones and Gilman (1915) have employed the method 

 with great success in controlling the yellows of cabbage. Norton (1914) 

 and Edgerton (1918) have selected tomatoes resistant to the Fusarium 

 wilt. 



In New York State, fields of the White Marrow bean are frequently 

 lacking in uniformity of type of the bean. Among the varying types 

 is a strain to which, for convenience, the name Flat Marrow has been 

 given by the writer. During the summer of 1915 it was observed that 

 this strain exhibited a high degree of resistance to the dry root-rot. 



In character the Flat Marrow varies somewhat, from a true White 

 Marrow to a Burlingame (or Medium, as it is commonly called in New 

 York State). The plant has a compact form of growth with broad and 

 dark green leaves. The stems are heavier than in the common Marrow. 

 The shape of the pod is that of a Medium, while frequent dashes of blue 



