MAINE AGRICUI,TURAL EXPERIMENT STATION. 1/ 



Bordeaux Mixture. Both copper and sulphur are efficient 

 fungicides, and so far the greatest success has been attained in 

 the use of compounds of one of these elements. In the earlier 

 years most of the work was done with various compounds of 

 copper. Of these, bordeaux mixture proved to be the most sat- 

 isfactory from all standpoints. It is an exceedingly efficient 

 fungicide and great success was attained by its use on many 

 varieties of apples. Other varieties it injured in varying 

 degrees. At Highmoor Farm on the Ben Davis and Baldwins, 

 while scab was well controlled, leaf injury was so great and 

 russeting of the fruit was so severe that the injurious effects 

 more than offset the good and bordeaux mixture had to be 

 abandoned. 



Lime-sulphur. Attention was then turned to various com- 

 pounds of sulphur. The best results have been secured with 

 what is known as lime-sulphur, a compound prepared from 

 (Jefinite quantities of lime, sulphur and water which are boiled 

 for a given time and then diluted to proper strength for appli- 

 cation upon the trees. This Station was among the pioneers in 

 the use of lime-sulphur as a means of controlling apple scab, 

 the first experiments being conducted in 1908. These were 

 made with the so-called, self-boiled lime-sulphur, which was 

 later discarded for the more efficient compound mentioned 

 above. It is doubtful if under all conditions lime-sulphur con- 

 trols apple scab as well as bordeaux mixture does, but on the 

 tenderer trees it is to be preferred. On the less susceptible 

 varieties bordeaux mixture is still recommended. Certain pro- 

 prietary compounds of sulphur, but differing from the ordinary 

 commercial or home prepared lime-sulphur concentrates, have 

 produced quite severe injury to both fruit and foliage. 



Method of Spraying. It has been found that the first foliage 

 spraying application is of prime importance in the control of 

 apple scab and why this is so. Valuable results have been 

 obtained upon the question of the proper dilutions of lime-sul- 

 phur to be used. Comparative studies between lime-sulphur, 

 bordeaux mixture and arsenate of lead as a fungicide have 

 given practical results. Arsenate of lead paste has been com- 

 pared with dry arsenate of lead powder and arsenate of zinc 

 with both. 



