1919 ENTOMOLOGICAL SOCIETY. , 21 



Owing to what api^ears to be an injurious effect of lime sulphur in reducing the 

 crop of apples in Xova Scotia, Mr. Sanders turned his attention to Bordeaux 

 mixture which had been almost entirely given up in favor of lime sulphur as the 

 fungicide in apple spraying. While it is, of course, not our function to investigate 

 fungicides we were compelled to study them as carriers of insecticides. In Nova 

 Scotia there is not the same demand for a scale destroying spray such as lime 

 sulphur as in Ontario owing to the absence of San Jose Scale, the existence of 

 which insect was chiefly responsible for the adoption of lime sulphur in other 

 parts of the country. 



Coupled with the scalicide properties of lime sulphur was its easy preparation 

 and the powerful advocacy of the manufacturers. ^Ye found that when Bordeaux 

 was substituted for lime sulphur in certain of the sprays we obtained better results 

 both from the point of view of production and condition of the foliage; we also 

 found that the trou))le of russeting could be obviated by not using Bordeaux in 

 the tbird spray, that is, the spray when the blossom petals have fallen which is 

 apparently the period when the setting fruit is most susceptible to the Bordeaux 

 injury. 



In view of the excellent results that we olitained in our experimental plots 

 and that have been obtained by some of the more prominent fruit growers in 

 Xova Scotia, we are recommending the use of Bordeaux mixture instead of lime 

 sulphur in the first, second and fourth sprays. In the third spray we find that 

 sodium polysulphide has given us the best results. As an insecticide we are 

 recommending in each spray the use of arsenate of lime. 



AVe have felt that far too little is known with regard to the chemistry and 

 bio-chemistry of spraying. Spray mixtures have often been recommended without 

 a careful study of their chemical constitution or of their effect on foliage, fruit 

 or insects. Accordingly, we are now making a very careful study of the chemical 

 Jiature of the different compounds that result from mixing various insecticides 

 with fungicides and of the effect of such compounds on the trees and on the 

 insects that they are expected to destroy. By these means we hope to secure exact 

 data that will enable us to experiment to better advantage and to secure results 

 of real value. 



But after all, I feel that the ultimate test will be made by the fruit grower 

 who will be the best judge as to the sprays giving the best results, and after 

 having carried out our investigations to the best of our ability we shall have to be 

 content to leave the matter in the hands of the grower. If we can demonstrate 

 to him the superiority of one spray over another he is generally willing to he 

 convinced and to act according to our advice. Further, it is a mistake to assume 

 that a spray combination that is the best in one fruit growing section of the 

 country will be the best in another. Spraying systems must be worked out to 

 suit the various localities. The day oi the universal spray calendar has long- 

 passed and for this reason we are endeavoring to study our spraying ]n-oblenis 

 locally. 



Peof. Caesar: I shall briefly answer Father Leopold's questions and then 

 ask Prof. Parrott to give us the benefit of his experiments in New York State. 



I myself intend to recommend as usual lime-sulphur for the first spray, that is 

 the one given either before or as tlie Inids are bursting or just after they have 

 burst. For the second spray, the one just before the blossoms burst, I shall recom- 

 mend either lime-sulphur, 1 gallon to 35 gallons of water, or Bordeaux mixture. 

 4.4.40, and to each of these either arsenate of lead or arsenate of lime. For 



