1921.] PUBLIC DOCUMENT — No. 31. 21a 



will be made the subject of a project. Its cause has not been 

 determined, but it appears to be of fungous origin. 



Eggplant. — In 1919 a disease of eggplant, evidenced by 

 wilting and death of the entire plant, was reported from the 

 market-garden sections of the State. One large grower lost a 

 large part of his crop. Preliminary investigation failed to 

 establish definitely the cause of the trouble, and in the absence 

 of this information the grower was advised to plant in 1920 on 

 new land not previously used for this crop. This was done, 

 with the result that the disease in question appeared in only 

 one row, and it developed that this row — the only one of the 

 1920 planting — was located on a section of the land where the 

 disease occurred in 1919. During the summer Mr. Krout 

 definitely determined the cause of the disease to be a fungus of 

 the genus Verticillium. This disease has been previously re- 

 ported in other parts of the country, but has had little attention 

 from investigators. 



Potato. — Late-blight of potato, always a possible menace to 

 the crop, took a heavy toll the last season. The disease 

 was first observed August 9. Abnormally high humidity 

 throughout August and September, with heavy rainfall in the 

 latter month, furnished conditions highly favorable to the 

 development of the causal fungus. As usual, fields carefully 

 and systematically sprayed with homemade Bordeaux mixture 

 suffered the least. Up to the time of this writing many reports 

 of storage rot due to late-blight have come to the department, 

 and it is probable that the loss from this source will be large. 



Apples. — A heavy crop of apples in a season of weather 

 conditions which favored the development of scab and black-rot 

 meant a large initial loss from these diseases in the orchard. 

 The heaviest outbreaks occurred in the eastern part of the 

 State, where early varieties, such as Gravenstein and Yellow 

 Transparent, suffered from black-rot, and Mcintosh from scab. 

 In one small area growers estimate that these diseases reduced 

 the value of their crop fully $200,000. The best control 

 measures known have been employed in eastern Massachusetts, 

 and their partial failure indicates that some factor or factors 

 have been overlooked. This points to just one thing, — the 

 need of investigation to determine how these diseases may be 



