Winter Meeting. 155 



In our experiments we have tried to answer the following ques- 

 tions: What remedies may be used without injury to the trees? If 

 removed and wounds treated, will the galls grow again? How may 

 trees be treated before planting? Can affected trees be treated while 

 growing in the orchard? Does the kind of soil have anything to do 

 with the occurrence of the galls? Is there any relation betw^een rasp- 

 berry and apple gall — that is, will one attack the other plant? And 

 will different methods of grafting influence the occurrence of the 

 galls? 



The investigation has been carried on for two years. In all 

 there has been nearly 3,000 trees used in the experiment and 275 

 different remedies and combinations employed. The following ma- 

 terials which are known to be more or less harmful to germs of all 

 kinds were used direct,^ in combinations and under different circum- 

 stances : 



Copper sulphate (bluestone), iron sulphate (copperas), sodium 

 chloride (common salt), lime, sulphur, formalin, ammonia water, 

 bichloride of mercury (corrosive sublimate), copper carbonate, car- 

 bolic acid, hydrocyanic acid, potassium dichromate, mercuric cyanide, 

 acid, hydrocyanic acid, potassium dichromate, mercuric cyanide, silver 

 nitrate, gas tar, kerosene oil, Bordeaux mixture and hot water. 



The remedies were used in three ways : By dipping the roots in 

 the materials ; by sprinkling the soil with the solutions until the 

 surface was wet just as trees were being planted ; and by cutting 

 away the galls and covering over the wounds with the materials to 

 prevent them growing again. 



RESULTS OF DIPPING EXPERIMENT AND SPRINKLING THE SOIL AS TREES 



WERE BEING SET. 



Formalin. — All strengths from ro per cent, down to i per cent., in- 

 clusive, killed nearly all the trees. Galls not killed on the few trees 

 remaining alive. Weaker solutions down to one-tenth of one per 

 cent, injured many of the trees, but the galls were apparently unhurt. 



By removing the galls and applying the formalin directly to the 

 wounds only, the trees were, in most instances, injured, but the galls 

 grew again. 



Bluestone. — Dippmg roots in bluestone, as well as sprinkling the soil 

 about the trees with the material in all strengths from one pound to 

 eight gallons of water, down to one to seventy-five gallons, killed all 

 of the trees. From one to 100 down to i to 300 injured the trees 

 more or less. Galls on all living trees. Where the galls were cut 



