35 



tracheiphilus, Smith.) and Wilt (Neccosmospora vasinfecla, (Atk.) 

 Smith.) have not been observed in Massachusetts on greenhouse 

 cucumbers. Bacteriosis has been observed on cucumbers out of 

 doors in Massachusetts, but inocculations of greenhouse soil 

 through pure cultures failed to produce this disease in one experi- 

 ment which was made on some winter grown plants. The Leaf-Glaze 

 (Acremonium sp.), Leaf-Spot (Phyllosticta Cucurbitacearum, Sacc), 

 and Scab (Cladosporium cucumerinum, Ell. & Arth.) have been 

 observed only once or twice on indoor cucumbers in this State. 

 Those diseases which are the most common are the following : 



Anthracnose. 

 (Colletotrichum Lagenarium, (Pass.) Ell. & Hals.) 



This fungus is responsible for a great deal of damage both on 

 cucumbers and on muskmelons and is quite frequently seen in 

 spring and summer on greenhouse cucumbers. We have never been 

 able to discover a case of infection during the early fall or 

 winter. The earliest record obtained in the spring is March 

 24, at which time it was just making its appearance on the vines. 

 The first indications of anthracnose are yellow spots on the leaves, 

 which multiply and enlarge, and in a very short time the whole plant 

 succumbs. The spread of the disease out of doors is frequently so 

 rapid that it requires only a few days for the entire crop to die. 

 Crops killed by this fungus present a dry, parched aspect, as if they 

 had been subjected to hot and dry winds of the greatest intensity. 

 Some growers have suggested as a possible cause of infection the 

 great difference between the day and night temperatures unavoid- 

 able in a greenhouse in spring after the fires have gone out, but the 

 more probable reason why winter infection does not occur is that 

 the fungus requires a resting period or that conditions are not 

 favorable. 



The best results* obtained by spraying out of door plants are not 

 very encouraging at the present time. Possibly by keeping the 

 moisture off the foliage as much as possible infection might be 

 avoided to some extent. In growing crops of muskmelons under 

 glass during the summer months, and keeping the foliage perfectly 

 dry, we have not experienced any trouble from this fungus, notwith- 

 standing it has been more or less common out of doors every season. 



*Dr. Halstead in X. J. Agr. Expt. Sta. Rept. XVII., 1896. pp. 340-343. 



