1902.] PUBLIC DOCUMENT — No. 33. 57 



KEPORT OF THE BOTAOTSTS. 



G. E. STONE, R. E. SMITH. 



The dying of cut-leaved birches. 



The present status of chrysanthemum rust in Massachusetts. 



The effects of desiccation on soil. 



Melon failures. 



Stem rots and wilt diseases. 



The present status of asparagus rust in Massachusetts. 



Sterilization of soil in greenhouses for fungous diseases. 



Similar lines of routine work and investio-ation have been 

 followed in this department as outlined in former reports. 

 During the summer, $400 was expended on repairs and im- 

 provements of the building, including part of the gTcen- 

 house, and more particularly upon the trucks and tracks 

 utilized for pot experiments. The shed and large unheated 

 greenhouse which were designed for truck experiments have 

 been retracked and concreted, and the original trucks, which 

 were rather primitive in construction, have been remodelled 

 and provided Avith roller bearings. 



Certain species of fungi affecting shade trees and economic 

 crops have been rather common during the year. Among 

 these may be mentioned the Gloeosporium ( G. nervisequum 

 (Fckl.) Sacc), Avhioh caused more or less defoliation of the 

 white oak throughout the State. In some instances the 

 foliage was affected to such an extent that half of it fell off 

 which was, as usual, replaced later on by a ncAV growth of 

 leaves. So far as I am aware, no treatment has ever been 

 given the oak for this disease. The fungus appears to be 

 confined to the lower portion of the tree, and no doubt a 

 good s|)raying of this part with soiuo standard fungicide as 

 soon as the leaves have unfolded and more or less developed 



