662 



Spraying Mixtures. 



[FEB., 



ment stations relating to spraying that I have read, not one 

 has entered into the subject of the effect of mixing spraying 

 materials from the point of view of possible decomposition. It 

 is not surprising, then, that in the numerous pamphlets on spray- 

 ing issued in the United States, chiefly by manufacturers of 

 spraying machines, the point in question is ignored ; and the 

 most incongruous mixtures are commonly to be found among 

 the prescriptions. 



It appears that a combination of Paris green and Bordeaux 

 mixture, in spite of the partial decomposition of the former, 

 remains the most effective combination of an insecticide and 

 a fungicide used at present, for which purpose it was recom- 

 mended in this Journal for April, 1905. For the first applica- 

 tion, just before the buds open, it would be harmless to the 

 trees ; but if applied immediately after the blossom has fallen, 

 when it is most needed for the destruction of the Codlin 

 moth caterpillar, my experience in last season's operations 

 induces me to advise that only 6 oz. instead of the usual 

 8 oz. per 100 gallons should be used, because the foliage is then 

 in a tender stage. The use of 8 oz., with Bordeaux mixture, at 

 this stage, greatly injured the foliage of my apples and plums. 

 That the Paris green was the cause of the injury was proved by 

 precise trials on trees not previously sprayed, a branch on each 

 of several apple trees being treated with Paris green at the rate 

 of 8 oz. to 100 gallons, other branches on different trees with 

 Bordeaux and Paris green, and a third set with Bordeaux alone. 

 Each branch was labelled in reference to its treatment, and it 

 was found that the Bordeaux mixture alone had no injurious 

 effect whatever' upon the foliage, whereas each of the other 

 applications caused scorching and ultimate defoliation. In this 

 experiment, it must be explained, the spraying was done with a 

 garden syringe, and the foliage was more nearly drenched than 

 it would have been by a spraying machine with fine nozzles. 

 But it is almost impossible to prevent men who do spraying 

 work from drenching the trees. They are not satisfied with 

 covering the foliage with a fine mist of spray, which is all that is 

 required, and, unless constantly superintended, they keep on 

 spraying a tree till the stuff drips off the leaves. 



The third spraying, often necessary to poison the food of 



