The CcDiadiati Horticulturist. 



289 



POISONING THE PASTURE UNDER THE TREES 

 BY PARIS GREEN. 



I 



AN important practical question 

 which I have tried to settle this 

 season — 1S89 — concerns the danger of 

 pasturing under trees which have been 

 sprayed with the arsenites. 



A gentleman wishing to spray his 

 orchard, in which he was pasturing 

 seventy-five hogs, consulted me as to 

 the wisdom of doing so without first 

 removing the swine. I told him I 

 believed there was no danger. I said 

 use a mixture, one pound of London 

 purple to two hundred gallons of water, 

 watch your hogs closely, and if any 

 seem affected remove all at once, and 

 I will l)e responsible for damages to the 

 amount of twenty-five dollars. The 

 gentleman did so and reports no damage. 



In the following experiments I used 

 the mixture of twice the strength which 

 should be used, that the experiment 

 might be the more convincing. I used 

 one pound to one hundred gallons of 

 water. In every case the spraying was 

 very thoroughly done. Care was taken 

 that every twig and leaf should be 

 drenched. 



In tree No. i a thick paper was 

 placed under one-half of a rather small 

 apple tree. The space covered was six 

 by twelve feet, or seventy-two square 

 feet. The paper was left till all drip- 

 ping ceased. As the day was quite 

 windy the dripping was rather excessive. 

 In this case every particle of the poison 

 that fell from the tree was caught on 

 the paper. Dr. R. C. Ked/.ie analyzed 

 the poison and found four-tenths (.4) of 

 a grain. Tree No. 2 was a large tree 

 with very thick foliage. Underneath 

 this tree was a thick carpet of clover, 

 blue grass and timothy just in bloom. 



The space covered by the tree was fully 

 sixteen feet stjuare, or c(iual to two 

 hundred and fifty-six .scjuare feet. As 

 soon as all dripping had ceased, the 

 grass under the tree was all cut, very 

 gently, and very close to the ground. 

 This was taken to the chemical labora- 

 tory and analyzed by Dr. R. C. Kedzie, 

 There was found 2.2 grains of arsenic. 

 Now as our authorities say that one 

 grain is a poisonous dose for a dog, 

 two for a man, ten for a cow, and 

 twenty for a horse, there would seem 

 to be small danger from pasturing our 

 orchards during and immediately after 

 spraying, especially as no animal' would 

 eat the sprayed grass exclusively. To 

 test this fully, I sprayed a large tree 

 over some bright, tender grass and 

 clover. I then cut the clover carefully, 

 close to the ground, and fed it all to 

 my horse. It was all eaten up in an 

 hour or two, and the horse showed no 

 signs of any injury. This mixture, 

 remember, was of double the proper 

 strength, was applied very thoroughly, 

 and all the grass fed to and eaten by 

 the horse. This experiment was re- 

 peated with the same result. I next 

 secured three sheep. These were kept 

 till hungry, then put into a pen about a 

 tree under which was rich, juicy, June 

 grass and clover. The sheep soon ate 

 the grass, yet showed no signs of any 

 injury. This experiment was repeated 

 twice with the same result. It seems 

 to me that these experiments are cru- 

 cial and settle the matter fully. The 

 analyses show that there is no danger, 

 the experiments confirm the conclusion. 

 — A. J. Cook, before Meeting of A. A. 

 A. S. at Toronto. 



