28 BULLETIN 1118, IT. S. DEPARTMENT OF AGRICULTURE. 
The spraying experiments of the writer were interrupted by the 
freeze of February, 1917, and later by circumstances resulting in part 
at least from war conditions. During several seasons no scab de- 
veloped in the orchards where spraying experiments were conducted. 
Nevertheless, a great many careful studies made of spray schedules 
employed in commercial groves in Florida and Alabama where scab 
was successfully controlled, together with the results of inoculation 
tests and of definite orchard spraying experiments, and of demon- 
strations, lead the writer to feel confident that the above-mentioned 
general conclusions are correct and that the disease can be controlled 
satisfactorily and economically. Good judgment must be used in 
selecting and applying the fungicide and in following it with insecti- 
cides if necessary. 
In addition to these field studies and observations, critical spraying 
experiments were conducted in a nursery of sour-orange and rough- 
lemon seedlings at Orlando, Fla., during 1919 and 1920. This 
nursery was set out in the spring of 1918 and was not sprayed that 
year, resulting in a very general infection on leaves and twigs to 
serve as sources of early infection the following year. 
During the progress of this spraying experiment for citrus-scab 
control in the nursery the following materials were used: 
Formula 1 : Bordeaux mixture, 3-3-50, prepared in the usual way. 
Formula 2 : Bordeaux mixture, 3-3-50, plus 0.5 per cent oil in emulsified form. 
The Bordeaux mixture was prepared in the usual manner to which sufficient 
oil emulsion was added to make 0.5 per cent oil in solution. 
Formula 3: Bordeaux mixture, 2-2-50, plus 0.5 per cent oil in emulsified form. 
Prepared in same manner as formula 2. 
Formula 4: Bordeaux mixture, 1-1-50, plus 0.5 per cent oil in emulsified form. 
Prepared in same manner as formula 2. 
Formula 5: Commercial Bordeaux paste (6 per cent metallic copper), 12$ pounds in 
50 gallons of water, the equivalent of 3-3-50, plus 0.5 per cent oil in emulsified 
form. 
Formula 6: Homemade Bordeaux paste, in proportions to equal 3-3-50 Bordeaux 
mixture, plus 0.5 per cent oil in emulsified form. 
Formula 7 : Burgundy mixture, 3-3J-50, prepared in the usual manner. 
Formula 8: Copper soap (Pritchard and Clark's (16) formula). Prepared by adding 
3 pounds of dissolved resin-fishoil soap to one-half pound bluestone dissolved 
in 50 gallons of water. 
Formula 9: Lime-sulphur solution, 32° B. diluted 1 to 40. 
Formula 10: Lime-sulphur solution, 32° B. diluted 1 to 40 plus stabilized oil emul- 
sion, 0.5 per cent. 
The oil emulsion used in these spray materials was prepared 
according to Yothers (32, p. 19) by emulsifying 2 gallons of mineral 
oil with 2 pounds (1 quart) of fishoil soap and 1 gallon of water. 
To dilute 3 quarts of this emulsion to 50 gallons gives a proportion 
of 1 per cent oil. 
In 1919 the sprays were applied at weekly intervals, beginning in 
March and continuing throughout the growing season. The applica- 
