576 Agricultural Experiment Station, Ithaca, N. Y. 



quantity of water. Now add the lime, and then add enough water 

 to satisfy the formula. If the ferrocyanide test is used, place a 

 spoonful of the mixture in a saucer or plate, and add a drop of the 

 test solution. If a red color appears, the mixture needs more lime. 

 If the test solution is added directly to a tank or barrel of the mix- 

 ture, the color reaction is apt to be lost in the mass. An excess of 

 lime ensures the safety of the mixture. 



7. The farmer should know what he wants to Tcill hefore he begins 

 to spray. — It is common to find a man who is going at spraying 

 with enthusiasm, but who can not explain a single definite object 

 which he has in view. He simply knows upon general principles 

 that spraying is useful. To such a man, spraying is spraying, 

 whether he uses Paris green or Bordeaux or both or neither one ; 

 and his results are about equal to his knowledge. There is no 

 longer excuse for such ignorance, for all the leading insects and 

 fungi have received more or less exact treatment in the publica- 

 tions of the experiment stations. The state of knowledge is far in 

 advance of the state of practice. 



I find many fruit-growers who need such elementary instruction, 

 as this : 



The arsenites (Paris green and London purple) are used to kill 

 all larvse or worms, and all those insects which chew the leaves or 

 shoots ; such as the codlin-moth, bud-moth, canker-worm, potato- 

 beetle, tent-caterpillar, and the like. Kerosene emulsion is used 

 for scale-insects and plant-lice. Bordeaux mixture and ammon- 

 ical carbonate of copper, are used to prevent the attacks of fungous 

 parasites ; as apple-scab, leaf-blight of the pear, quince and plum,, 

 potato blight, and such like. 



The times and seasons of spraying depend entirely upon the 

 enemies which it is desired to reach, and upon the weather. 



S. When to spray. — The grower himself must decide when and 

 how often to spray, because he should know what enemies he desires 

 to reach. If he has the bud-moth, he should spray with the first 

 swelling of the buds, and if he has the plum-scale he should spray 

 in the winter. But leaving the special insects aside, it is safe to say 

 that for the two staple enemies — the apple-scab and the codlin- 

 moth — at least two sprayings should be given. I am not yet con- 

 vinced that spraying when the tree is dormant has any appreciable 

 effect in destroying the apple-scab fungus. As a general statement 

 I should say, spray twice upon apples and pears, once just as th& 



