DISEASES OF PLANTS. 147 



per acre, sown broadcast aud thoroughly mixed with about 2 in. of the surface 

 soil just before the iX)tatoes were planted, considerably i-educed the amount of 

 scab. In no cases, however, was scab entirely eliminated. When lime was 

 applied at the rate of from 350 to 400 lbs. per acre in conjunction with 450 

 lbs. of sulphur, the fungicidal i)ower of the sulphur was reduced to practically 

 nothing. Whore the same quantity of lime with 900 lbs. of sulphur was used 

 the fungicidal value of sulphur was not i-educed, and at the same time its 

 injurious after effect on the crop was considerably diminished. 



Sulphur added to commercial fertilizer reduced the value of the fertilizer 

 more or less noticeably, although a small quantity of sulphur, about 100 lbs. per 

 acre on certain soils, was found to have some fertilizing value for potatoes. 

 Where it was used in quantities of over 300 lbs. per acre it seemed to be more 

 or less injurious to the crop. As a rule the effect of sulphur treatment on the 

 potato crop in the succeeding season is that of reducing yield and scab, the 

 scab being reduced more than the yield. 



A bibliography is appended. 



Powdery scab of the potato, R. P. Gorham {Dept. Agr. Now Brunswick, 

 Hort. Div. Leaflet 3 (1914), PP- 6, figs. 3). — A description is given of this disease 

 of potato, with measures recommended for its control. These include the use 

 of only such seed as are known to be free from the disease, as there is no 

 known remedy for potatoes when once infected, the spores remaining virile in 

 the soil for many years. 



The Rhizoctonia disease of potatoes, W. J. Morse and M. Shapovalov 

 (Maine Sta. Bui. 230 (1914), pp. 193-216, pis. ii).— Attention is called to the 

 disease of potatoes due to Rhizoctonia solani or Corticiiini vagmn solani. It 

 is said to be widely spread and lately observed as seriously affecting the 

 potato crop in parts of Maine, where poor uneven stands, low yields, and pre- 

 mature ripening are reported. Field observations and greenhouse experiments 

 have been conducted to learn the nature of the injury and method of control. 



In the experiments with fungicides, solutions of corrosive sublimate and 

 formaldehyde destroyed the sclerotia of the fungus. Lime, which has been 

 recommended for its control, was tested in pots with little success. Some ob- 

 servations were made on the liability of varieties of potatoes to the disease, 

 most of the experiments, however, being carried on with the varieties Irish 

 Cobbler and Green Mountain. 



While the experiments thus far have shown no definite means of control, the 

 authors recommend seed disinfection with corrosive sublimate solution before 

 planting and rotation of crops, allowing as long a time as possible between 

 successive crops of potatoes. 



A bibliography is apjiended. 



A new disease of spinach, P. Voglino (Ann. R. Accad. Agr. Torino, 56 

 {1913), pp. 377-379). — ^The author describes the attack and progi-ess of a para- 

 site on spinach in Savona and in Turin, Italy. The fungus is said to be Col- 

 letotrichum spinaei(e, which was studied in this connection. 



Tomato diseases, J. B. S. Norton (Maryland Sta. Bui. ISO (1914), PP- ^02- 

 114). — The author describes a number of tomato diseases, among which the 

 most troublesome are said to be the Fusarium wilt, due to F. lycopersici and the 

 leaf blight caused by Septoria lycopersici. 



For the control of the Fusarium wilt the author thinks the most promising 

 method for relief is the growing of resistant varieties. In a test, about 40 

 varieties showed marked differences in their susceptibility to attacks of the 

 fungus. In experiments for the control of the leaf blight, practically all 

 varieties grown in this country and Europe have been tested and all showed 

 about the same susceptibility to the fungus attack. Spraying with Bordeaux 



