17 



any experiments of that kind. There must be something in 

 the Tanglefoot that is gradually absorbed by the bark and 

 which is injurious to the peach tree. Tanglefoot is being 

 used on shade trees, (which have thick bark), without in- 

 jury, so far as I know, but the bark of the peach tree is 

 thin and may absorb these materials more easily. 



MR. I. I. MARGESON. Is there any injury from 

 spraying with arsenate of lead? 



PROFESSOR BLAKE. We have never had any injury 

 from spraying with arsenate alone just after the petals fall. 

 At the time the calyx is being shed we always use self -boiled 

 lime-sulfur with the arsenate of lead. I think there might 

 be more danger from the arsenate of lead spray after the 

 trees are in full foliage, if no self-boiled lime-sulfur were 

 used, but from the studies in New Jersey it would seem that 

 there would be no advantage in spraying with arsenate of 

 lead after the period when the calyx is being shed. 



MR. L. W. RICE. Did I understand you that there 

 was no difference that you could see between sulphate of 

 potash and muriate of potash? You are recommending the 

 t.Tse of muriate because it is cheaper, aren't you? 



PROFESSOR BLAKE. Yes. Of course, it might be 

 that one of these forms might give somewhat different re- 

 sults on different soils, but so far, with us, there has been 

 no difference between the two. I might say that in our 

 experiments we have limed the soil rather freely where 

 these tests have been made. 



MR. MUNROE MORSE. You spoke of using self- 

 boiled lime-sulfur for spraying after the trees start in the 

 spring. Would there be any difference in the result if 1 

 used a solution of the commercial sulfur? 



PROFESSOR BLAKE. Our experience with the 

 solutions of the commercial lime-sulfur has not been satis- 

 factory. If we used mixtures that were any more concen- 

 trated than about 1 to 125, we found burning was liable to 

 occur; and mixtures more dilute than that did not control 

 the peach scab as well as the self-boiled. I believe the 

 Delaware Experiment Station will have something new to 

 report upon the use of concentrated lime-sulfur before very 

 long; they think they have found the element that causes 



