THE MONTHLY BULLETIN. 441 



Naturally, the increasing evidence of injury induced by Bordeaux 

 mixture called forth a deal of investigation on the part of agricultural 

 investigators in the several state experiment stations as well as in the 

 Federal Department of Agriculture. As a result of such work, the fol- 

 lowing points seem fairly well established : 



i^irsf— Bordeaux injury is a definitely recognized trouble. 



Second — Improperly made Bordeaux is not the sole cause of injury, 

 and excess of lime does not seem to have an appreciable effect in pre- 

 venting it. 



Third — Bordeaux appears to be aggravated in its injurious action by 

 unfavorable weather conditions following the time of spraying. Wet 

 weather so following is especially conducive to injury. 



Fourtli — Agencies such as frost and other factors not accounted for 

 may produce a characteristic russeting on fruit, entirely independent of 

 any spray. 



Fifth — Varieties vary greatly in susceptibility to injury. 



Sixth — The severity and general occurrence of injury in certain sea- 

 sons of untoward weather conditions make it probable that weather is an 

 important factor in causing injury. Even small differences of local 

 atmospheric conditions may account for entire difference of results. 



The means by which such injury is effected by the spray was also 

 extensively studied by scientists both in this country and abroad. The 

 differences of opinion regarding the actual method of injury have no 

 place in a brief discussion of this kind. Suffice it to say that the fact 

 accepted by all investigators in this field is that the copper of the copper 

 sulphate in the Bordeaux mixture is the injurious element ; recognizing 

 this fact, the next step was to find a satisfactory fungicidal substitute in 

 which the copper containing compounds would be eliminated. 



In this effort attention was chiefly directed to solutions of sulphur in 

 chemical combination. The result has been the now widely used and 

 deservedly popular lime-sulphur sprays. 



In connection with these lime-sulphur sprays it is interesting to note 

 that a lime-sulphur mixture was recommended for the treatment of 

 grapes affected with mildew as early at 1833, long before the general use 

 of fungicides. This was the forerunner of the now well known "self- 

 boiled" lime-sulphur mixture of Mr. W. M. Scott, formerly of the 

 United States Department of Agriculture. 



Two forms of lime-sulphur sprays have been used as fungicides since 

 1907 — the self-cooked or so-called ' ' self-boiled ' ' preparation devised and 

 first used by Mr. W. M. Scott, and the boiled solution first tried as a 

 summer spray by Prof. A. B. Cordley of the Oregon Experiment Station. 



Briefly, self -boiled lime-sulphur is a chemical and mechanical combi- 

 nation of calcium of sulphur obtained 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. 



