204 



BACTERIA IN RELATION TO PLANT DISEASES. 



FORMUL/E. 



Copper Sulphate. 



Dissolve in hot water, or by suspending the 

 crystals in a sack in the top of the cold water. 

 This is best done over night. It is convenient 

 to make a strong solution (i or 2 pounds per 

 gallon) and dilute as needed. 



Ammoniacal Solution of Copper Carbonate. 



Use 5 ounces of copper carbonate, 3 pints or 

 less of strong ammonia water (26 B.), i. e., 

 just enough to bring the copper carbonate 

 into solution, and 50 gallons of water. The 

 copper carbonate must be wet with water first 

 and then stirred into the ammonia after the 

 latter has been diluted with 5 or 6 volumes of 

 water. Add always a slight excess of the 

 copper carbonate and use only the supernatant 

 clear liquid. 



Used on foliage and fruit when Bordeaux 

 mixture would be unsightly. Apply frequently 

 in case of rainy weather. 



Bordeaux Mixture. 



There are various formulae in which the first 

 figure represents pounds of copper sulphate, 

 the second figure pounds of stone lime and the 

 third gallons of water. The 6 : 4 : 50 is the 

 usual combination and sticks better than the 

 4:6: 50. It also sprays easier. For sensitive 

 plants 4:4 : 50 may be used or 4 : 5 : 50. 



The lime must be of good quality and fresh 

 slaked. Air slaked lime must not be used, 

 neither should concentrated solutions be mixed, 

 nor hot solutions. Divide the 50 gallons of 

 water into two equal parts. Dissolve the cop- 

 per sulphate in one part. This is usually done 

 over night. Slake the lime with a portion of 

 the other part, adding the water slowly, then 

 add the remainder of the water when the lime 

 has ceased to be lumpy. When ready to spray, 

 stir thoroughly to obtain an even mixture of 

 the lime and water and pour the two fluids 

 together through a strainer tied across the top 

 of a clean barrel. The two streams should 

 blend as they fall to insure a good product, 

 the essential features of which are alkalinity 

 and a fine grain insuring suspension in the fluid 

 long enough to permit of the spraying, which 

 should be undertaken at once. Concentrated 

 solutions give a coarse precipitate which settles 

 quickly. The mixture should be absolutely 

 free from sawdust, sticks, straws, chaff, wool, 

 fragments of leaves or any similar substances. 

 Otherwise, vexatious delays are likely to arise 

 from clogging of the nozzle. In spraying use 



a good force pump. A Vermorel nozzle affords 

 a well distributed fine spray. For dilute 

 Bordeaux reduce the copper sulphate one-half, 

 or double the volume of water. This may be 

 sprayed upon soils to check the damping off 

 of seedlings. 



Stock solutions of the two fluids may be 

 prepared in advance and will keep indefinitely. 

 They are conveniently kept in tubs or half 

 barrels closely covered, the lime always under 

 the required volume of water, and the copper 

 sulphate in strong solution. When needed one 

 then has only to measure out a portion of the 

 copper sulphate water, dilute it to the required 

 volume, stir up the settled lime very thoroughly, 

 dip out the required volume of the milk of lime 

 quickly, and pour the two fluids together, as 

 already described. 



An acid Bordeaux should never be sprayed 

 upon plants. The following are tests for acid 

 Bordeaux : ( i ) A film of metalic copper deposited 

 on polished iron or steel when plunged into 

 the mixture; (2) a purplish red reaction on 

 puttine into the Bordeaux a drop of a water 

 solution of yellow prussiate of potash (i to 10). 

 If either of these reactions is obtained more 

 lime must be added. It is best to avoid dry 

 Bordeaux and similar commercial substitutes. 



Resin Bordeaux. 



This is made by adding to each 50 gallons 

 of Bordeaux a clear liquid made by boiling 

 for one hour i pound resin and 0.5 pounds 

 crystals sal soda in 0.5 gallon water. Another 

 way of making it is to melt 5 pounds of resin 

 in i pint of fish oil, slowly add i pound of 

 potash lye, stirring, and taking care that it 

 does not become too hot and boil over. Then 

 add 2 gallons of water and continue boiling 

 for an hour. Finally add slowly with stirring 

 an additional 3 gallons of water. The finished 

 product should dissolve readily in cold water. 

 Two gallons of this soap is added to each 50 

 gallons of the finished Bordeaux. Resin fish 

 oil soap may also be bought and may be added 

 to Bordeaux at the rate of 5 pounds per 50 

 gallons. 



Soda Bordeaux. 



Soda lye i pound; copper sulphate 3 pounds; 

 lime 5 ounces ; water 50 gallons. 



A r senate of Lead. 



Three pounds to 50 gallons of water, mixed 

 thoroughly with a little water first. 



