EXPERIMENT STATION BULLETINS. ~ 401 



FORMULAS. 



BORDEAUX MIXTURE. 



Copper Sulphate 4 pounds 



Fresh Lime (unslal^ed) 4 to 6 pounds 



"Water 40 to 50 gallons 



Care should be taken that the lime is of good quality and well burned and 

 that it has not become air-slaked. If only a small amount is to be slaked it 

 will be best to use boiling water, and the lime should not be allowed to become 

 dry while slaking. When much Bordeaux is to be prepared, it is a good plan to 

 make up stock solutions which can be mixed as required, proceeding as follows: 

 Dissolve 40 pounds of copper sulphate in 40 gallons of water and in a box slake 

 40 or more pounds of lime. These can be kept for some time, but it is best not to 

 prepare more than can be used in a week or ten days. Each gallon of the solu- 

 tion will contain one pound of the copper sulphate, and in preparing it for spray- 

 ing, as many gallons should be used as are necessary to furnish the proper amount 

 of copper sulphate. Thus for each 40 gallons required, 4 gallons of the solution 

 should be placed in a barrel in which there are 16 gallons of water. An equal 

 weight of lime, as near as can be estimated, should be placed in another barrel 

 and 20 gallons of water added to this. After being well stirred, the lime mixture 

 should be allowed to stand for a minute to give the coarse particles time to 

 settle, and then the lime water should be dipped out and slowly poured into 

 the copper sulphate solution, stirring rapidly as the lime water is poured in. 

 The mixture is then ready for use, but as there is danger of burning tender 

 foliage if the amount of lime is insufBcient, it is well to use some simple test, 

 such as dipping a knife blade in the mixture or adding a few drops of ferro- 

 cyanide of potassium (yellow prussiate of potash). If the amount of lime is 

 not sufficient, copper will be deposited upon the knife blade, while the ferro- 

 cyanide of potassium will give the mixture a deep brownish-red color. More 

 lime should be added if necessary until no discoloration is caused in either case. 

 A slight excess of lime will do no harm and is always desirable. 



The copper sulphate can be easily dissolved, if suspended in the water in a 

 coarse sack or basket. If the lime is properly slaked and is handled as recom- 

 mended, there will be little trouble from lumps, but it is always well to strain 

 the lime-water through a sieve, such as a piece of window screening. 



This is the best remedy for fungous diseases except while the trees are dormant, 

 or as the fruit is ripening. It is especially valuable for use with Paris green 

 and other arsenites, as it lessens the danger of their injuring the foliage and 

 the washing effect of rains. 



DUST SPRAYS. 



In places where water cannot be easily obtained, and upon rough and rolling 

 land, the dust sprays have some advantages, but, while they are easier to apply 

 and are less expensive, they are much less effectual against fungous diseases, and 

 hence the liquid sprays should not be abandoned where they can possibly be 

 used. The dust sprays are of value, to supplement the liquid applications, for 

 both broods of codling moths and for the plum curculio. For the last named 

 insect the dust spray gives excellent results. 



Formula 1. 



Copper sulphate 6 pounds 



Paris green 1 to 2 pounds 



Lime 100 pounds 



Formula 2. 



Copper sulphate 6 pounds 



Sulphur 10 pounds 



Paris green 1 to 2 pounds 



Lime 100 pounds 



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