STATE POMOLOGICAL SOCIETY, 5 1 



3. If lime-sulphur sprays do not injure fruit or foliage and 

 yet are not equal to bordeaux as a spray, is their use com- 

 mercially profitable? 



4. Can arsenate of lead be as safely and effectively used 

 with these sprays as with bordeaux? 



THE NATURE OE EIME-SUEPHUR SOLUTIONS. 



What are these lime-sulphur mixtures, and how do they differ 

 from one another? Briefly, self-boiled lime-sulphur is a chem- 

 ical and mechanical combination of calcium and sulphur ob- 

 tained by adding sulphur to an equal weight of lime when that 

 lime is slaking. The means of effecting this union is the heat 

 of the slaking lime ; no other heat is employed. The spray so 

 made is not as strong as the boiled preparations, and has less 

 sulphur in solution. Probably for this reason it has been found 

 less effective for apple scab. 



The boiled lime-sulphur solution is made by slaking good 

 lime, and after slaking boiling with an amount of sulphur double 

 in weight to that of the lime used. Actual boiling is continued 

 from 30 to 60 minutes, according to the recommendations of 

 various experimenters. 



It is known that calcium and sulphur will combine in differ- 

 ent proportions and form different compounds ; the greater the 

 amount of sulphur present, up to a certain point, and the longer 

 the time of boiling, up to about an hour, the greater the amount 

 of sulphur in solution. The home-made preparations have, of 

 course, a considerable amount of sediment left, which is strained 

 off before using. 



The commercial solutions are usually clear, but have not been 

 found essentially different from the properly prepared home- 

 boiled preparations. 



THE EXPERIMENT. 



For this experiment 25 rows of Ben Davis trees, about 20 

 to 25 years old, were selected in our thriftiest orchard. These 

 were divided as follows : 



Rows one, two and three, contained a total of nine trees. The 

 balance of the plats consisted of two rows of six trees each, ex- 

 cept the plot sprayed with the home-boiled solution, which had 

 II trees. The trees were fairly alike in size and condition. 



