306 STATE BOARD OP AGRICULTURE. 



MANUFACTURE AND STORAGE OF THE LIME-SULFUR SPRAY. 



BY 



ANDREW J. PATTEN. 



Circular No. 10. 



During the past year man}' requests have been made upon the chemical 

 division of the Experiment Station for some specific information on 

 certain points in regard to the manufacture and storage of the lime- 

 sulfur spray. As the literature on the subject did not furnish the desired 

 information, the investigations reported in the following pages were 

 undertaken during the past summer. 



The methods of analysis used and a technical discussion of the in- 

 vestigation are published in Technical Bulletin No. 6. 



The possibilities of substituting the lime-sulfur solution, as a summer 

 spray, for the Bordeaux mixture have brought this spray solution very 

 prominently to the front during the past few years. Then too, since 

 Headden has shown that, in Colorado, the continued use of arsenical 

 sprays has resulted, in many cases, in serious injury to the trees and also 

 that the fruit from trees thus sprayed actually show traces of arsenic, 

 this subject has become of very great economic importance. 



It is very doubtful, however, that the same conditions existing in Col- 

 orado will ever prevail in the State of Michigan on account of the dif- 

 ference in the soil conditions. Yet, the very fact that we are loading up 

 our soils with materials in the form of spray solutions, that are actively 

 poisonous should demand the attention of every one concerned. Although, 

 at the present time, there may not be, and probably is no danger from the 

 use of the arsenic compound, how long can this practice be continued 

 with impunity? How long will it be before the danger and the damage 

 from the excess of arsenic incorporated into the soil may be even greater 

 than the damage due to the insects? 



These are questions that should demand the attention of every thinking 

 person and should encourage a search for some less poisonous materials 

 to take the place of the arsenic compounds. 



As a contact insecticide and fungicide the lime-sulfur solution is to be 

 liighly recommended because it possesses no poisonous jiroperties. As a 

 stonuich poison it cannot of course replace the arsenical compounds in 

 combating the sucking insects but it is not beyond reason to believe 

 that some comj)ounds may be found, less poisonous than arsenic, that 

 will x)rove equally effective. 



Lime and sulfur may form several combinations depending upon the 

 amount of sulfur uniting with a definite quantity of lime, or more 

 properly speaking, the element calcium. Theoretically one element of 



' This investigation was conducted by Mr. Ja?). S. Harris, temporarily connected with this division 

 during the summer of 1910. 



