TENTH ANNUAL REPORT. 101 



and killed. This, and the fact that all stages of the disease may 

 be observed at any given time during the growing season, and 

 also some experiments made by Dr. Mnrrill, of the New York 

 Botanical Gardens, with cultures made from material furnished 

 by us, would show that no period of rest is necessary, but that 

 the spores are able to begin a new cycle of growth immediately 

 upon ripening. This of course tends to increase the virulence 

 of the disease. 



Early last June this disease was noticed on so many widely 

 scattered trees of all sizes that specimen branches and an appeal 

 for information were sent to the United States Department of 

 Agriculture at Washington. The mycologist of the Bureau of 

 Plant Industry — Mrs. Flora W. Patterson — identified this speci- 

 men as being a fungus of the Genus Cytospora, and stated that 

 no species of this genus had been reported as being injurious to 

 chestnuts, and apparently the fungus was a true parasite. From 

 the specimen received it would seem that no mechanical injury 

 to the bark was necessary to enable the fungus to gain admittance 

 to the live plant cells of the branch. The cutting out and imme- 

 diate burning of all affected branches and limbs, and the spray- 

 ing of all the trees with Bordeaux Mixture, were recommended. 



The sum of $2,000 was therefore asked for with which to begin 

 operations, and upon its appropriation a force of experienced tree 

 pruners was immediately set to work. From the start it was real- 

 ized that work of some magnitude was at hand, and operations 

 were therefore pushed with the utmost energy. The number of 

 trees out of which all diseased material was cut was 438. Of 

 a number of these trees only the bare trunk remains, it being 

 necessary to cut away everything else. 



In the meantime steps were taken to procure a power-spraying 

 machine, and after much consideration the Niagara Gas Spraying 

 Company's outfit was decided upon as being the lightest, most 

 effective, and most simple machine on the market. Its cost is 



$175- 



This machine consists of a 150-gallon tank and an 8-foot 

 tower, both of steel, mounted on a platform truck which is pro- 

 vided with wide wheels. The power for spraying is derived from 

 a series of steel tubes containing commercial carbonic-acid gas 

 under a pressure of about 1,200 pounds to the square inch. 

 Through suitable fittings these tubes are connected with the tank 

 containing the spraying liquid, and the supply is governed by a 

 valve wherewith to regulate the pressure upon the liquid. Usu- 

 ally the pressure is about 125 pounds to the square inch. Before 



