COMBATING APPLE SCAB. 31 



Spraying Program for 1922. 



A series of plots in triplicate were laid off in the three orchards pre- 

 viously mentioned. The sprays used were home-made Bordeaux mixture 

 alone, home-made Bordeaux mixture and liquid lime-sulfur, home-made 

 Bordeaux mixture and dry lime-sulfur, a 4-50 and a 3-50 dry lime-sulfur, 

 liquid lime-sulfur, and liquid lime-sulfur plus lime. 



Powdered arsenate of lead, at the rate of 2 pounds to 50 gallons of 

 spray, and 40 per cent nicotine sulfate, at the rate of three-eighths pint 

 to 50 gallons of spray, were used -nith all the different spray materials 

 in the delayed-dormant, pink and calyx. In the fourth summer spray 

 arsenate of lead was used but the nicotine was omitted. 



In the Sabine and Knights orchards the plots were rectangular, 4 rows 

 of 6 trees each, except the check at Sabine's which had 16 trees, and the 

 Bordeaux-dry lime-sulfur plot at Knights' which had 20 trees. In the 

 Frost orchard the plots consisted of single rows of 8 to 11 trees. The 

 data were taken from 5 typical trees of the two middle rows of each plot 

 in the Sabine and Knights orchards; and in the Frost orchard, from 5 

 typical trees of each row. The trees of each of the three sprayed orchards 

 were approximately twelve years old. 



Treatment of Plots. 



All plots, except the checks, were given the delayed-dormant applica- 

 tion. The plots in the Sabine and Knights orchards were sprayed with 

 a 1-10 liquid lime-sulfur plus arsenate and nicotine. The plots in the 

 Frost orchard were sprayed with a 15-50 dry lime-sulfur plus arsenate 

 and nicotine. Plots 1 to 8 were conducted in each of the three orchards. 

 Plots 9 to 11 were conducted only in the Frost orchard. The plots in the 

 Sabine orchard were the only ones given the fifth summer spray. The 

 detailed treatment of plots follows : — 



Plot 1. — Check, unsprayed with fungicides. The same insecticides were used 

 as on the other plots. A single check plot was used in each of the Sabine and Frost 

 orchards. In the Knights orchard two check plots were necessary, because the 

 Bordeaux plot was located in a separate block of trees. 



Plot 2. — A 3-10-50 home-made Bordeaux mixture ' for the pink spray, and a 

 1-50 liquid lime-sulfur for the calyx and following sprays. 



Plot 3. — The same as plot 2, except that dry lime-sulfur was substituted for 

 the liquid. 



Plot 4- — 1-50 liquid lime-sulfur. 



Plot 5. — 4-50 dry lime-sulfur. 



Plot 6. — 1-50 liquid lime-sulfur plus 6 pounds of lump lime to 50 gallons of 

 spray. 



Plot 7. — A 3-10-50 home-made Bordeaux mixture for the pre-pink and pink, 

 and liquid lime-sulfur for the calyx and succeeding sprays. 



Plot 8. — A 3-10-50 home-made Bordeaux mixture only. 



1 Directions for making Bordeaux mixture may be obtained by applying to the Extension 

 Service, Massachusetts Agricultural College. Ask for Extension Leaflet No. 33. 



