New York Agricultural Experiment Station. 385 



leaf -spot late in summer,* For this reason it seemed desirable 

 to compare the Bordeaux mixture with the eau celeste soap 

 mixture as a remedy for this disease. Previous comparisons 

 of these two fungicides have usually resulted in favor of the Bor- 

 deaux mixture when considered with reference either to its 

 effectiveness against the spread of fungi or to its elfect on the 

 health of foliage. Were eau celeste as good a fungicide as Bor- 

 deaux mixture it would be more desirable because it contains no 

 heavy sediment, does not need to be agitated and is easier to ap- 

 ply than is Bordeaux mi:^ture. 



In 1895 a comparison of these two mixtures was made by the 

 Station Horticulturist to see which is preferable for fighting 

 the leaf -spot. Two other questions pertaining to the treatment 

 of the leaf-spot were also investigated, namely: 



What is the least number of sprayings by which this disease 

 may be kept under control? 



At what time should these sprayings be made in order to do 

 the most good? 



An account of these investigations was published in Bulletin 

 98, a portion of which is included in this report. 



Plan of Experiments in 1896. 



In 1896 the investigations as to the least number of sprayings 

 that are desirable and the best time for making them was con- 



* The following is the history of the use of eaii celeste Id the plum orchai d above referred to 

 as given by the nianag»r, Mr. C. U. Scoou : 



In the suiumer of 1892 the foliage began ilroppiujT from a block of Bavay's Green Gage to au 

 alarming extent. The trees had been sprayed twice in the sjiing with Bordeaux mixture 

 although not so thoroughly as they should have been. At the suggestion of Mr. D. G. Fairchild 

 an eau celeste soap mixture was tried to see if it would check the trouble. Three applications 

 were made, at inteixals of abouf ton days, beginning the last of July and extending into 

 August. The immoiliate result was that the spread of the disease seemed to bo checked. The 

 most marked result was apparent in the fall, when the untreated trees dropped nearly all of 

 their foliage before the fruit was picked while the sprayed trees retained their leaves till late iu 

 the season. The following winter was quite severe on plums and many trees were injured. 

 Those trees which had been sprayed and hold their leaves late in the fall were injured less than 

 those trees which were not sprayed and which lost ihoir leaves earlier 



In 189;! the trees were sprayed in the spring with Bordeaux mixture more thoroughly than 

 they had been iu the previous year. Two applications of the eau celeste were made, one the 

 latter part of ,1 uly the other iu August. The contrast between the treated and untreated trees 

 was not so great a.-) in tho previous year, as the untreated trees held their foliage well, but in 

 the fall it was noticed that the treated trees held their foliage longer than the untreated. 



Iu 1894 a block of Italian Prune was given trcaliii.iil .siinihii- to that which the Bavay's (Jreeu 

 Gage received in 1893 aiid with similar results. 



25 



