The Canadian Horticulturist. 



279 



showers, or can jar the trees when 

 the rains are very frequent. For the 

 apples we can use London purple, 

 one pound to 200 f^jallons of water. 

 For the plums we must use Paris 

 green, one pound to two or three 

 hundred gallons of water. If the 

 carbolated plaster is preferred, we 

 use one pint of crude carbolic acid to 

 fiftv pounds of land plaster. This is 

 thrown freely over the trees, so as to 

 strike every plum on the tree which 

 is being treated. 



Care must be taken not to spray 

 the plum trees until the blossoms are 

 all fallen, as otherwise it will kill all 

 bees that visit the poisoned flowers. 

 He suggested that it be made con- 

 trary to law to spray the trees with 

 arsenites before the falling of the 

 blossoms. Respecting the injur}- 

 done the foliage by the use of arsen- 

 ites, he said : London purple is 

 more injurious to the foliage than is 

 Paris green, and white arsenic — ar- 

 senious acid — is more harmful than 

 is either London purple or Paris 

 green. This is doubtless owing to 

 the soluble arsenic which is quite 

 abundant in London purple and al- 

 most absent in Paris green. London 

 purple may be used on apple, plum, 

 cherry, pear and most ornamental 

 trees, but on these should never be 

 stronger than one pound to two 

 hundred gallons of water. If the 

 application is to be repeated, as it 

 must be for the curculio, to prove 

 effective, or if it is to be used in June 

 or July, Paris green should be used, 

 in the same proportion as above, or 

 else we should only use one pound of 

 London purple to three hundred gal- 

 lons of water. I now think that this 

 necessity is more due to time of ap- 

 plication than to the fact of increased 



quantity of the poison. If the arsen- 

 ites are to be used on the peach, to 

 defend against the curculio, Paris 

 green only should be used, and that 

 not stronger than one pound to three 

 hundred gallons of water. 



The injur}' done to the foliage is 

 never immediately <-(/)parent. It usu- 

 ally shows somewhat tiie second da}-, 

 l)ut the full injury is frequently not 

 manifest till the fifth day, and often 

 not till the tenth. He likewise dem- 

 onstrated that there is no danger 

 of cattle being poisoned by eat- 

 ing the grass under the sprayed 

 trees. 



Prof. Clarence M. Weed, of Col- 

 umbus, O., read a paper on a similar 

 subject — remedies for the plum cur- 

 culio. An experiment with cherries 

 was made, spraying half an orchard 

 with London purple (i lb. to 160 gals, 

 of water.) He then picked cherries 

 from sprayed trees and unsprayed 

 trees, and in every case there were 

 more wormy cherries on the unspray- 

 ed than on the sprayed trees. The 

 average was : — Unsprayed trees, 

 eight per cent, of wormy cherries; 

 sprayed trees, three per cent, of 

 wormy cherries. The benefit from 

 the spraying, hence, was 75 6-10 per 

 Cent. Experiments were also made 

 with plums, when an orchard of 

 plums was sprayed with London 

 purple several times. An enormous 

 crop was the consequence, although 

 two untreated trees had their entire 

 yield destroyed. He concluded that 

 very much of the damage done by 

 the curculio could be safely and 

 cheaply prevented by the use of ar- 

 senites. Prof. Saunders, of Ottawa, 

 expressed his opinion that Paris 

 green was a better arsenite to use 

 than London purple. 



