374 STATE- HORTICULTURAL SOCIETY. 



parts of the leaves. But those parts which were easily reached were quite 

 free from mildew, as were also the parts in which the liquid collected after 

 the applications. The same is also partly true of the other plots, but 

 on them the material was evenly applied. It may be that the hydrate of 

 copper does not remain so evenly distributed upon foliage when it is 

 applied without lime; this would largely account for the above difference. 



It is impossible to give the relative merits of these fungicides after but 

 one season's test. More trials must be made and the formulas modified 

 before final judgment is passed. But some of the substances appear more 

 promising than others. 



Conclusions. — The hydrate of copper when applied alone is not so 

 effective against fungi as when applied in the Bordeaux mixture. When 

 used at the rate of ^ pound in 22 gallons of water, it reduced injury from 

 fungi at least five per cent. 



The action of the borate of copper as a fungicide is not very marked 

 when the compound is applied in an undissolved condition. When used 

 at the rate of ^ pound in 22 gallons of water it reduced injury from fungi 

 about twenty per cent. 



The chloride of copper as a fungicide gave better resiilts than the Bor- 

 deaux mixture. When used at the rate of three ounces dissolved in 22 

 gallons of water it reduced the injury from mildew 35 per cent. It is the 

 most promising of the new fungicides tested. 



The Bordeaux mixture reduced injury from fungi about 25 per cent. 



SUMMARY. 

 1. Carbonate of Copper, 



a. The action of the ammoniacal carbonate of copper as a fungicide 

 does not appear to be lessened by the addition of Paris green or London 

 purple. 



b. the ammoniacal carbonate of copper gave better results as a fungi- 

 cide when used at the rate of 1| ounces dissolved in one pint of ammonia 

 and diluted with 92 gallons of water, than when three ounces of the car- 

 bonate and one quart of ammonia were used. 



c. The fungicidal action of a combination of the carbonate of copper 

 held in suspension in water, and the arsenites, is not marked. 



(I. Combinations of the ammoniacal carbonate of copper and Paris 

 green or London purple, or, of the carbonate of copper suspended in 

 water and these arsenites, have a caustic action upon foliage as a rule. 



e. Paris green renders the ammoniacal carbonate of copper more caustic 

 than does an equal amount of London purple; but 



/. When London purple is applied in connection with carbonate of cop- 

 per held in suspension in water the combination is more caustic than one 

 in which an equal amount of Paris green is used. 



2. Sulphate of Copper. 



a. The effect of the combinations of the sulphate of copper and Paris 

 green and London purple upon fungi was unsatisfactory. 



b. The action of the commercial sulphate of copper upon foliage is 

 uncertain. 



c. The injury done to foliage by the sulphate of copper was increased 

 from 10 to 20 per cent, by the addition of Paris green or London purple. 



