DUST SPRAYING. 47 1 



the maiden introduction of the system rests on such a solid founda- 

 tion. The results obtained in the orchard by the practical grower 

 are never questioned, they are taken as sure indexes to better re- 

 sults and better methods when toned down by experience and prac- 

 tice. 



To those of the practical fruit growers who have used the system 

 the longest, and endeavored by experience to perfect the process, its 

 many advantages over the water conveyor are well known and may 

 be summed up briefly, as follows : 



Firstly, its simplicity. 



In dry forms the arsenics are easily and readily mixed with the 

 lime, the amalgamation is perfect, no settling, and the lowest grade 

 of help can apply them to the trees without danger to the foliage. 

 When the formulae are mixed, muscular strength is the only requi- 

 site for successful application. 



Secondly, its low cost, ease and rapidity of application. 



One man can do work equal to three men using the liquid con- 

 veyor ; a dust machine weighing only loo pounds is equal to a four- 

 horse water outfit in working capacity. 



In the old system, blue stone, or sulphate of copper, alone, is the 

 insecticide. These arsenates are conveyed to the tree or plant by 

 water. The conveyor has no virtue either as a fungicide or an in- 

 secticide — it simply carries the potent elements of the formula to the 

 tree and is not only useless, expensive and unpleasant to handle, but 

 also introduces the element of danger and uncertainty by causing the 

 burning of the foliage and rusting of the fruit. In the use of water 

 as a conveyor the grower is always handicapped by the character of 

 the foliage he is treating and must vary the strength of the arsenics 

 to suit it ; hence the limitation of the remedial agencies, no matter 

 how virulent the attack may be, either of insects or fungus. This 

 principle is at variance with the rational and natural treatment of 

 disease, either in plant or human life. In addition to this, in making 

 the Bordeaux mixture chemical changes immediately take place, and 

 various insoluble compounds are formed that destroy the positive 

 action of the sulphate of copper, rendering the compounding of the 

 mixture so intricate that even the highest grade of professional skill 

 cannot always produce the same results. A fungicide formula that 

 requires such nicety and exactness in compounding, where only a 

 single potential remedy can be used, is not well adapted to the wants 

 of the fruit grower who is compelled to compound it, and must of 

 necessity give unsatisfactory and varying results. What is needed 

 by the fruit grower is a simple fungicide formula that will give the 

 standard fungicide, Paris green or some substitute is the standard 



