The Canadian Horticulturi^ 



Vol. XXXIII 



MARCH, 1910 



No. 3 



The Preparation and Use of Concentrated Lime- Sulphur 



J. p. Stewart, Experimental Horticulture, State College, Pennsylvania 



THE spraying part of the horticulti- 

 cultural world is just now in a state 

 of transition. This transition in- 

 volves the breaking away from Bordeaux 

 mixture and the whole list of copper 

 sprays which have served for more than 

 a quarter of a century as fungicides and 

 the taking up of what may become an 

 equal list of sulphur sprays. It also in- 

 volves the abandonment of old formulas 

 and processes for making the latter 

 sprays, and the substitution of more def- 

 inite, economical and less disagreeable 

 methods. Just how complete the transi- 

 tion will be can hardly be predicted now. 

 But this much is certain that, whereas 

 two years ago we might easily have told 

 how best to spray a tree, to-day we must 

 wait for further results before this ques- 

 tion can be finally answered. 



Among these coming sprays, the clear, 

 concentrated lime-sulphur solution wiy 

 undoubtedly occupy a leading place. In 

 the commercial form this solution al- 

 ready has a satisfactory insecticidal rec- 

 ord of some seven or eight years. In the 

 new home-preparation, it has an excel- 

 lent record both as an insecticide and 

 fungicide, being first used by Cordley of 

 the Oregon Station in 1907. Realizing 

 the importance of this work, in the latter 

 part of 1908, the writer undertook to de- 

 termine the essential features of the pre- 

 paration of storable lime-sulphur solu^ 

 tions and, if possible, render their use 

 available to orchardists. 



In brief, the results of this study are 

 as follows : In the making of a storable 

 lime-sulphur at home, we must first get 

 the formula right. This is accomplished 

 by using one pound of good lime, (one 

 containing 90 to 95 per cent, calcium 

 oxid and as little magnesium as possible), 

 two pounds of sulphur, and one gallon or 

 a little more of water, boiling it all down 

 so as to havQ about one gallon of total 

 product at the close. This i — 2 — i for- 

 mula can be made up in any quantity, 

 merely noting that the pounds of lime 

 and the gallons of final product are the 

 same in number, while the pounds of 

 sulphur are just twice as many. 



The kind of sulphur may be either 



•Penn. E»pt. Sta. Bui. 92, July. 1909. This 

 bulletin contains full practical directions for 

 making, preserving and diluting lime-salphur 

 Folntions, together with a table of uses Tt mav 

 be obtained for the asking by writing the Experi- 

 ment Station, Btate College, Pa. 



flour, flowers, or "powdered commer- 

 cial" at least 99 V2 per cent. pure. The 

 last named is probably most desirable, 

 with the flour next, on account of cheap- 

 ness and the somewhat lessened tendency 

 to form pellets in the process of mixing. 



The utensils needed are a cooker, 

 measuring stick, strainer and hydrometer. 

 Their total cost need not exceed $15. 

 They are described in detail in our Bulle- 

 tin No. 92*, so that it will suffice here to 

 say that the cooker may be of either iron 

 or wood and use either bottom heat or 

 steam. If steam is used it is preferable 

 for accurate work that it be in closed 

 coils rather than live steam, at least in 

 the latter stages of the process. This is 

 merely because it is desirable that the 



Two Reasons 



The Canadian Horticulturist 

 should be in the homes of every 

 amateur horticulturist in Canada 

 for two reasons : First, it is a 

 worthy exponent of all that is in- 

 teresting and desirable in horti- 

 culture ; and secondly, it has a 

 unique inverse ratio in its mission, 

 being the lowest in price and the 

 highest in quality. — W. M. Rob- 

 son, Lindsay, Ont. 



final volume be under control and be de- 

 creasing rather than increasing. Steam 

 jacketed kettles with mechanical agita- 

 tors are available and they work very 

 nicely indeed. But where storage is not 

 considered and lower densities are per- 

 missible, there is no objection to mak- 

 ing the material with the use of live 

 steam throughout. 



DETAILS OF PREPARATION 



In making fifty gallons of concentrate 

 the procedure is as follows : Materials : — 

 50 lbs. best stone lime (not over 10 per 

 cent, impurities), 100 lbs. sulphur (kind 

 stated above), 50-55 gallons of total pro- 

 duct, at finish. 



Put ten gallons of water in kettle and 

 start fire. Place lime in kettle. After 

 slaking is well started, add the dry sul- 

 phur and mix thoroughly, adding enough 

 water lo maintain a thin paste, which re- 

 quires about five gallons. After the slak- 

 ing and mixing are completed, add water 

 to the height of fifty gallons on the meas- 



«9 



uring stick and bring to a boil and stir 

 until the sulphury scum practically dis- 

 appears. Then add water (preferably, 

 but not necessarily, hot) to the sixty gal- 

 lon height and boil again to fifty gallons, 

 if storage space is limited. If it is not 

 limited, a little more water may be added 

 the third time, and boiling stopped 

 at about fifty-five gallons. The ma- 

 terial should be kept well stirred, 

 especially during the early stages of 

 the process, and any lumps of sulphur 

 or lime should be thoroughly broken up. 

 (If cooker is large enough, the whole 

 amount of water may be added immedi- 

 ately after mixing in the sulphur, thus 

 avoiding the check in boiling though 

 greater care is required to prevent boil- 

 ing over. A seventy-five gallon cooker 

 is large enough for this). 



The time of boiling should be until the 

 sulphur granules are evidently dissolved. 

 This is best determined by dipping and 

 slowly pouring some of the material, un- 

 der close observation. In many cases we 

 have obtained as complete dissolving of 

 the sulphur in less than forty minutes of 

 actual boiling as was obtained by any 

 time up to two and a half hours. In gen- 

 eral a period of forty to sixty minutes of 

 actual boiling should be safe and sufficient 

 to put the sulphur into solution. But the 

 amount of sulfites and sulfates and, 

 therefore, the sediment, are undoubtedly 

 increased by unduly prolonged boiling. 

 Hence the amount of water added in the 

 third addition should be so regulated as 

 to permit the necessary boiling and ^ust 

 reach the desired volume at the close. 

 This gives the least sediment and the re- 

 gulation can be easily accomplished after 

 a few trials. 



The finished product may be immedi- 

 ately poured or strained into a barrel or 

 settling tank. The straining is merely a 

 safeguard to prevent possible clogging 

 due to imperfect materials or failure to 

 break lumps in the sulphur. When pro- 

 perly made the amount of sediment left 

 in the strainer is insignificant. To avoid 

 any considerable loss of materials, it 

 may be washed with part of the water 

 used in making the next lot, simply pour- 

 ing the water through the strainer into 

 the kettle, and any lumps of sulphur dis- 

 covered may be broken up and used 

 again. 



(Continued on page esj 



