THIRTY-SEVENTH ANNUAL REPORT. 29 



of lime commonly recommended, and we should have no injury. We use 

 equal quantities of lime and copper sulphate, and twice as much lime as 

 copper sulphate, three times as much lime as copper sulphate, and four times 

 as much lime as copper sulphate. 



And still a fourth experiment was to determine whether we could control 

 the apple scab by using a lesser quantity of copper sulphate. 



I don't want to go into the details of these experiments. You would not 

 be interested in them, and besides they are published in a bulletin which 

 all can have from our station. I only want, in summing up, to give you the 

 results obtained, and make an application of them to your conditions. 



Taking up the first of the experiments: It became apparent from the 

 very start there was no doubt but that Bordeaux mixture and Bordeaux 

 mixture alone caused this russeting of the fruit. It began to show within 

 two days after applied to the trees, began to show on fruit and leaves. On 

 the other hand, on the checked trees there were no traces of it whatever. 

 So that we were very sure that in all our experiments, not only on the station 

 ground, but in all the cooperative exneriments, it was fully demonstrated 

 the cause of this peculiar russeting of leaves and yellowing of foliage was due 

 to the Bordeaux mixture and to the Bordeaux mixture alone. There were 

 no arsenites in the mixture at all, and no substances, so it could only have 

 been the Bordeaux mixture. 



As to the second experiment, the influence of wet weather: It became 

 apparent almost from the start, too, that wet weather was the great un- 

 favorable condition for such using. Within a day after the trees had been 

 sprayed, when sprayed just before a rain or during a rain, this injury began 

 to show; while, when trees were sprayed during sunny weather or weather 

 that would permit the mixture to dry upon the fruit, almost no injury was 

 shown, and this injury became cvnnulative as time went on. There seemed 

 to be a total disassociation of the copper sulphate and of the lime if the 

 mixture was applied during a wet time. This was true, to some extent, 

 of sprayings made in the afternoon or evening preceding dewey nights, nights 

 in which much dew fell ; showing that even dew could cause a disassociation 

 of the lime and of the copper sulphate. 



With regard to the value of an excess of lime: In all the experiments 

 (there was not an exception) it was found that the excess did not prevent 

 the injurious action of the copper sulphate. The mixtures in which we used 

 an equal quantity of copper sulphate and lime were as free from injury 

 as those in which we used twice or treble or four times as much. So that 

 I am now sure, and I feel that the apple growers in Western New York are 

 all agreed that there is no value, no particular value, in adding an excess 

 of lime to Bordeaux mixture; it is as good a mixture with equal quantities 

 of lime and copper sulphate as it is with any greater addition of the lime. 

 Two interesting facts came out in this experiment. One was that in wet 

 weather the action of the copper sul ph ate in controlling the scab was a little bet ter 

 with an excess of lime; and the other was that in the dry weather spraying, 

 the beneficial effects of copper sulphate in controlling the scab were lessened 

 with the application of lime; they just offset each other. So we could see 

 no benefit in recommending at any time — not being able to predict the 

 weather — an excess of lime for Bordeaux mixture. 



The outcome of the last of the four experiments, that of determining 

 the value of different strengths of copper sulphate, ought to be pleasing to 

 you, inasmuch as copper sulphate is becoming more and more expensive. 

 We found we could control the scab just as well with three pounds of copper 



