66o 



Spraying Mixtures. 



[FEB, 



SPRAYING MIXTURES. 



At the opening of the new spraying season it may be of some 

 advantage to call attention to a point connected with the opera- 

 tion which hitherto has been strangely neglected. That point is 

 the suitability or unsuitability for mixing of various materials 

 used in spraying. Fruit-growers and managers of spraying 

 experiments not infrequently mix materials without any con- 

 sideration of the chemical reaction which may take place 

 between two or mere of them. In combining insecticides and 

 fungicides there is, of course, a desire to battle with the two 

 classes of fruit pests in one operation ; but if the materials 

 chosen for this double purpose will decompose each other and 

 enter into fresh combinations, it is important to consider what 

 those combinations will be, whether they will be harmful or 

 inert, and whether they will be mechanically objectionable on 

 account of the difficulty of passing the mixture through the 

 nozzles of a spraying machine. 



Extremely few fruit-spraying trials have been made in this 

 country, but they have been numerous in the United States, 

 and it was the practice of mixing materials in that country 

 which led me to make some inquiries as to the effects of such 

 mixing, and as to mixtures which seemed worth trying if they 

 could be used without decomposing the effective elements. 



Some mixings cause partial decomposition of constituents, 

 and yet leave them apparently effective. A notable example 

 is the combination of Paris green and Bordeaux mixture. 

 Messrs. Blundell, Spence and Co, manufacturers of Paris green, 

 state that the addition of Bordeaux mixture to it decomposes 

 the Paris green, producing a much less poisonous and efficient 

 combination of the copper and the arsenic. But it is partly for 

 the purpose of reducing the poisonous action of Paris green that 

 the addition of Bordeaux mixture to it is commonly recom- 

 mended and practised in the United States. The mixture has 

 stood the trial of prolonged experience, and its effectiveness as 

 an insecticide and fungicide combined has been demonstrated in 

 numcous experiments. The objection to it, as to Paris green 

 alone, is that it often seriously injures the foliage of fruit trees, 

 even when used in such moderate proportions as 8 oz. of Paris 



