Plant Sanitation. 



39(5 



SULPHUR AND OTHER FUNGICIDES. 

 Li me-Sulphur-Salt Wash. — The fungicide called lime-sulphur-salt wash is 

 made up as follows : 



Many different formulas are used in making up this wash, all apparently 

 good and giving almost the same result when not too dilute. The above formula 

 seems to be the best, and has been extensively used. If the lime is high-grade 

 stone lime, 15 pounds will be sufficient to dissolve all the sulphur. With average 

 lime 20 pounds is the better quantity, but with poor or partly air -slaked 

 lime 25 to 30 pounds are necessary. Lime absorbs an equal weight of water in 

 becoming air-slaked. The writer has used partly air-slaked lime with good results, 

 but in weighing out the lime the water in air-slaked lime must be taken into 

 account and a larger quantity used. 



Preparation in small quantities.— Place about 10 gallons of water in an iron 

 kettle over a fire, make the sulphur into a paste with a little water, and when 

 the boiling point is nearly reached add the fresh lime and the sulphur together. 

 The mixture should be constantly stirred and the boiling continued for forty 

 to sixty minutes. The object of the cooking is to dissolve the sulphur, and when 

 this is accomplished further boiling is useless but not harmful. 



The salt may be added at any time during the process of boiling or entirely 

 omitted. It is generally conceded, however, that salt increases the adhesive- 

 ness of the wash as it does ordinary lime whitewash, and for this reason it is 

 perhaps advisable to use it, although it is not supposed to strengthen the fungicidal 

 property of the mixture. Possibly, also, the salt hastens the solution of the 

 sulphur by raising the boiling point or by its insolvent action. 



It has been found that the sulphur dissolves more readily in a concen- 

 trated mixture with lime, and the quantity of water used during the process 

 of boiling should, therefore, be reduced to a minimum. The mixture should not 

 be allowed to become pasty, however, and water, preferably hot, should gradually 

 be added till the barrel is nearly full when finished. When the cooking is 

 completed pass the mixture through an iron wire strainer (not brass or copper) 

 and dilute with the required amount of water. 



The wash may be applied either hot or cold with practically the same 

 results, though the warm mixture is less likely to clog the nozzles. If allowed 

 to stand over night, sulphur crystals will form on tne bottom and sides of the 

 containing vessel, necessitating reheating or straining before application. It 

 is difficult to dissolve the lime-sulphur crystals after they have once formed. 

 For this reason it is better not to prepare more than can be used the same day. 



Preparation in large quantities.— The lime-sulphur-salt wash requires so 

 much work in boiling and mixing that it affords an opportunity for ingenious 

 arrangements of outfits and plants. Where only a few barrels of the mixture 

 are to be made— say for not more than a few hundred trees— boiling in a kettle 

 or hog-scalder, or feed-cooker, will answer very well. In fact, quite extensive 

 spraying operations are carried on in California by the use of a battery of iron 

 kettles set in brick furnaces and fired with primings and dead wood from the 

 oi'chards. 



The most economical and convenient way is to prepare a steam plant 

 with tanks or barrels for boiling the spray by steam. Several different forms 

 are in use. Some of the first very successful steam plants consisted of elevated 



Lime, unslaked 



Sulphur (flour or flowers) 



Salt 



Water to make 



pounds 20 



do 15 



do 10 



gallons 50 



