21 



tion left unsprayed is subject to the attack of the scab fungus or may 

 allow a codling-moth larva to escape. 



Overspraying to be avoided. — The operator should endeavor to deposit 

 the spray in the form of a fine mist, covering the leaves with small 

 drops, and should be careful to stop at this point, viz, before the mix- 

 ture collects in larger drops and drips from the tree. Less will be 

 left on the leaves if the spraying is continued too long and an unnec- 

 essary amount of the mixture is used. 



COST OF SPSAYING. 



The cost of spraymg varies so greatly under different conditions 

 that only approximate figures can be given. The varying factors are 

 the wages and efficienc}" of the labor employed, the capacity of the 

 spraying outfit (the work can be done cheaper with a large outfit than 

 with a small one), the size and condition of the trees, the conveniences 

 provided for preparing and holding the mixture, the nearness to Avater, 

 etc., and, lastly, the cost of materials. 



The cost of the difi^erent arsenicals varies rather widely. Lime 

 arsenite with soda is cheapest, its cost being little more then one- 

 quarter that of either Paris green or lead arsenate and about one- 

 half that of Scheele's green. The fruit grower can judge for himself 

 whether it is worth his while to go to the trouble of home preparation 

 of the cheaper arsenicals. 



Bordeaux mixture prepared fresh at home is both cneaper and 

 more effective than the read3^-made article. The farmer should by 

 all means make his own mixture. Biuestonc fluctuates in price, but 

 is obtainable in moderate quantities for about 7 cents per pound. 



Materials for spraying 100 trees with Bordeaux mixture and arsen- 

 icals can be had for from $2 to $3. The cost of application is likely 

 to exceed the cost of the materials. Records of the actual expense 

 incurred in spraying orchards vary from 5 cents to 30 cents per tree 

 for the entire season's work of three to six sprayings. 



SPHAY INJURY TO rOI.IAGE OB, FRUIT. 



No injury should result from the sprays recommended in this bul- 

 letin if properly prepared and applied, though such injury is occa- 

 sionally reported to occur under unusual weather conditions or when 

 mistakes have been made. This is indicated by the burning of the 

 leaves, especially of the tips and margins, and a russeting of the fruit. 

 To avoid this injury, follow directions exactl3^ Take special care to 

 have the lime pure and freshly slaked. An excess of lime will do no 

 harm and should be vised if any spray injury is observed. Do not use 

 more bluestone or arsenical than advised. 



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