38 MASS. EXPERIMENT STATION BULLETIN 214. 



largely responsible for this difference. Temperature and humidity were 

 quite high when many of the applications were made in 1921, while to a 

 certain extent the opposite was true in 1922. Apples should never he 

 sprayed when temperature and humidity are both high, as burning of foliage 

 is almost ceHain to resxdt. 



The amount of spray applied does not seem to be as important a factor 

 in burning the foliage as was formerly thought. In 1922 the writer se- 

 lected trees in several plots in the Sabine and Knights orchards and 

 thoroughly drenched tliem with the spray at the pink and calyx apphca- 

 tions. At the end of the season the trees showed only slight injury. 



Sulfur dusts have never burned the foliage, while burning from copper- 

 lime dust is frequent. 



Recommendations for 1923. 



Spraying Program. 



It should be borne in mind that the spray schedule which follows is 

 based on only two years of experimental work, and therefore is subject to 

 change. Where two or more spray materials are given, the first is pref- 

 erable and should be used whenever possible. 



Delaijed-dormant. — Fifteen pounds of dry lime-sulfur dissolved in 50 

 gallons of water, or 1 gallon of liquid lime-sulfur in 9 gallons of water. 



Pre-pink. — A 3-10-50 home-made Bordeaux mixture, or 3 to 4 pounds 

 of dry lime-sulfur dissolved in 50 gallons of water, or 1 gallon of liquid 

 lime-sulfur in 49 gallons of water. 



Pink. — A 3-10-50 home-made Bordeaux mixture, or 3 to 4 pounds of 

 dry lime-sulfur dissolved in .50 gallons of water, or 1 gallon of liquid lime- 

 sulfur in 49 gallons of water. 



Calyx. — Three to 4 pounds of dry lime-sulfur dissolved in 50 gallons 

 of water, or 1 gallon of liquid lime-sulfur in 49 gallons of water. 



Fourth and Fifth Simimer. — Same as the calyx. Unless the rainfall of 

 June, July and August is above normal, the fifth summer spray may not 

 be necessary for the control of scab. On the other hand, if these months 

 are rainy and scab is bad, the fifth summer application will be found 

 very profitable. 



Three-eighths of a pint of 40 per cent nicotine sulfate to each 50 gallons 

 of spray is used at the delayed-dormant, pink and calyx applications. 

 Also, 2 pounds of powdered lead arsenate to each 50 gallons of spray are 

 used at the delayed-dormant, pink, calyx and fourth summer applications. 



Dusting Program. 

 If a dusting program is to be followed, the delayed-dormant spray 

 should be appHed. Dusting sulfur should be used for the pre-pink and for 

 all applications after the fourth summer dust. A dust composed of 90 

 parts sulfur and 10 parts arsenate of lead should be used for the pink; 

 an 85-15 dust for the calyx and fourth summer applications. In case 



