Massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 246 OCTOBER, 1928 



Control of Red Spider and Powdery 

 Mildew on Greenhouse Cucumbers 



By W. D. Whitcomb and E. F. Guba 

 Contribution from the 



Market Garden Field Station 



of the 



Massachusetts Agricultural College 

 Cedar Hill, Waltham 



Large losses in yield and quality of greenhouse cucumbers result from 

 the attacks of red spider and powdery mildew and from failure to use 

 effective control measures promptly and correctly. Satisfactory treat- 

 ments for controlling these pests individually are now available but the 

 materials which are used cannot be combined or applied closely following; 

 one another with safety. The incompatibility of these materials is a 

 serious handicap to the successful control of these pests when both are 

 present on the vines. This bulletin suggests the proper choice of materials 

 for effective and safe control by a combination treatment, as well as 

 methods of greenhouse management which tend to check the damage by 

 red spider and powdery mildew. 



Requests for Bulletins should be addressed to the 



AGRICULTURAL EXPERLMENT STATION, 

 AMHERST, MASS. 



