27 



and fruit. The arsenical is best used as an ingredient added to the 

 Bordeaux mixture, which is the standard remedy for the control of 

 fungous diseases. Wlien an arsenical is used simply in water the 

 vineyardist should always add, to each 50 gallons of the liquid, the 

 milk of lime made from slaking 2 to 3 pounds of good stone lime. 



Paris green. — This is used at the rate of 1 pound to each 100 or 

 150 gallons of liquid, whether water and milk or lime or the Bordeaux 

 mixture. Paris green should be worked into a paste with water be- 

 fore being added to the liquid in the spray tank, to prevent its ad- 

 hering in small lumps. When used with Bordeaux mixture, the latter 

 will probably serve to hold it well on the vines, giving results perhaps 

 equal to those produced by arsenate of lead. 



Scheele's green. — This arsenical is similar to Paris green, being the 

 simple arsenite of copper containing no acetic acid, and hence consid- 

 erably cheaper. It is a much fuier pow^der than Paris green and re- 

 mains in suspension longer. It is used in the same way and at the 

 same strength recommended for the former poison. 



Arsenate of lead. — There are now numerous brands of arsenate of 

 lead on the market, and vineyardists should be careful to buy an effi- 

 cient and safe kind. Some preparations sold as arsenate of lead con- 

 tain an amount of free arsenic dangerous to foliage, and an unneces- 

 sary amount of water may also be present, thus lowering the quantity 

 of poison when used at a given strength. A proper arsenate of lead 

 should contain no free arsenic and should have as much as 50 per cent 

 actual arsenate of lead. Ai'senate of lead is used at the rate of 3 to 6 

 pounds to each 50 gallons of liquid, and, as it comes in the form of a 

 putty-like paste, must be worked free in a little water in a bucket or 

 other suitable vessel before it is added to the spray tank. It may be 

 used much stronger than any other arsenical and it adheres well to 

 the foliage. For these reasons it is preferred by many vineyardists. 



Arsenite of lime. — This is much the cheapest of the arsenical poi- 

 sons. On apple it is stated to be very satisfactory, and it should be 

 equally so on grape. It seems not yet to have been used to any ex- 

 tent on grape, and should be tried first in a small way. It may be 

 prepared at home according to the following formula : 



White arsenic pounds . . 1 



Sal soda crystals do 4 



Water gallon. . 1 



All of the ingredients are boiled together for a few minutes or until 

 dissolved, and any water lost by evaporation should be restored. 

 This constitutes a stock solution, 1 pint being used with each 40 or 50 

 gallons of Bordeaux mixture. Wlien it is used in water the vineyard- 

 ist must add the milk of lime made from slaking 2 to 3 pounds of good 

 stone lime, which is necessary to produce the arsenite of lime. 



CONTACT REMEDIES. 



For insects which secure their food by sucking the juices from the 

 plant, such as the grape leaf-hopper and aphides, contact insecti- 

 cides must be used. Two such insecticides are whale-oil soap solution 

 and kerosene emulsion. These preparations are not ordinarily used 

 in Bordeaux mixture. They are sprayed on the vines in the usual 

 way. 



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