34 



MASS. EXPERIMENT STATION BULLETIN 214. 



some unexplained reason the Bordeaux-dry lime-sulfur plot yielded onlj^ 

 49 per cent clean fruit and 90 per cent marketable fruit. The fact that 

 the total yield of this plot was exceptionally low may justify leaving it 

 out of consideration. 



Liquid Lime-Sulfur tersus Dry Lime-Sulfur. 



For two years dry lime-sulfur has given as good control of scab as the 

 liquid form (Tables IV, V and VI). Four pounds of the dry form in 50 

 gallons of water have been used for all sprays except the delaj^ed-dormant 

 in most of the work, but judging from this year's results 3 pounds will 

 give as good results. Some growers use only 2 pounds in 50 gallons, but 

 in the opinion of the writer this is too dilute. 



Dry lime-sulfur has the advantage of less bulk, and it is claimed that 

 the fungicidal value is not injured by freezing. Both the dry and liquid 

 forms of lime-sulfur used with lead wdll burn the foliage under certain 

 conditions, but judging from the data at hand the liquid form seems to 

 burn slightly more than the dry. 



The Cost of Speaying. 



In figuring the cost of spraying the writer has used the data from the 

 experimental plots of 1922. It is assumed that there are 30 twelve-year- 

 old Mcintosh trees to the acre. Dry lime-sulfur and insecticides are 

 used as indicated in the suggested spraying schedule for 1923: dry lime- 

 sulfur, 15 pounds to 50 gallons of water for the delayed-dormant, and 4 

 pounds to 50 gallons of water for the four later applications; powdered 

 lead arsenate, 2 pounds to 50 gallons of spray; and nicotine sulfate, 

 three-eighths pint to 50 gallons of spray. Four gallons of spray are al- 

 lowed for each tree. The cost of lime-sulfur is placed at 10^ cents per 

 pound; powdered arsenate of lead at 14 cents per pound; and nicotine 

 sulfate at $14 per gallon. Sprajing with either liquid lime-sulfur or 

 Bordeaux mixture costs slightly less than with dry lime-sulfur. 



Table III. • — Cost of Spraying One Acre of Apple Trees. 



