34 NEW YORK STATE MUSEUM 



since the latter aids materially in keeping the preparation upon 

 the trees. Thorough and continuous agitation is necessary when 

 paris green is used and should not be overlooked with other 

 poisons. The arsenite of lime^ is the cheapest poison which 

 can be employed and has been extensively used in the fruit- 

 growing sections of western New York. It is comparatively 

 safe if used with bordeaux mixture. In recent years large 

 amounts of arsenate of lead, usually a commercial preparation 

 sold under a trade name, have been employed with great satis- 

 faction. This poison is much more adhesive by itself than either 

 paris green or arsenite of lime, and on account of its 

 insolubility is much less likely to injure the foliage by burning. 

 It is one of the safest poisons which can be employed. Arsenate 

 of lead should be purchased on a guaranty as to the amount of 

 arsenic contained, since there is considerable variation between 

 the different brands. It is not particularly profitable for the 

 fruit grower to pay for filler. It is the poison he is after. 



The experience of the last two seasons has shown that it is 

 possible to use a poison, especially arsenate of lead, with a dilute 

 lime-sulfur wash (one of the standard commercial washes 

 diluted with 30 parts of water). The advantage of this com- 

 bination lies in the fact that so far this dilute lime-sulfur wash 

 has caused no material injury to either foliage or fruit, while 

 it has proved most effective as a fungicide and the poison has in 

 no manner lost its efficiency as an insecticide. It should cer- 

 tainly be tried further, though the results thus obtained do not 

 warrant unmodified recommendation. 



A word as to the possibility of ultimate injury to orchards 

 receiving one or more applications annually, of an arsenical 

 poison. Prof. William P. Headden of Colorado has published a 

 bulletin giving a warning in regard to this matter and stating 

 that in his opinion, many trees in that state were being killed 

 by applications of poison. It is but fair to state that other 

 investigators in an adjacent state and one in New York State 

 attribute the injury to other causes. So far as the writer can 



^Arsenite of lime may be prepared by dissolving i pound of white arsenic 

 and 4 pouncs of sal soda (carbonate of soda, washing soda) in i gallon of 

 water by boiling in an iron vessel 15 minutes or till the arsenic dissolves, leav- 

 ing only a little muddy sediment. Add the water lost in boiling and use i pint 

 of this stock solution to each 40 gallons of water to which 2 pounds of freshly 

 slacked lime have been added, or a pint of the stock solution may be added 

 to 40 gallons of bordeaux mixture. This stock solution will keep indefinitely 

 in a closed vessel. It is very poisonous and should be properly labeled. 



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