70 FUMIGATION INVESTIGATIONS IN CALIFORNIA. 
Pa po. 
Fumigation against citrus Bcales, improved system 
advantages 63-64 
apparatus \ -61 
dosage schedule 
in use I 
procedure 61-63 
supply carl 59-61 
method of computing dosage and volume for 
tented trees 25-26 
methods for obtaining measurements and dos- 
age of trees with and without apparatus... . 26-30 
present system, apparatus 18-19 
dosage schedules 19-24 
procedure 18-19 
procedure in improved system • 
present Bystem 18-19 
proportion of materials used by rumigators 32-39 
simplification by improved system 68 
sulphuric acid, amount necessary . 
effecl ol too great an excess. . . 34 
jar and cover 60-61 
removal from drums and car- 
boys 
supply cart ">!!-i;0 
table to replace supply cart on very rough 
ground 61, 62 
tents, marking for estimating dosage... 27-30,55-^56 
sheet 17-18 
time of year 4S-52 
tray for carrying chemicals in present system. . 18-19 
water as a factor 34-35 
correct proportion 
effect of different proportions on tem- 
perature and amount of available gas. 
while fruit is small 5 L-52 
purple scale 40-46 
length of exposure 44-4-3 
preliminary experiments 40-43 
generators, cover 
Fungus, black, or sooty-mold, on citrus trees infested with black scale 15 
Honeydew, secretion by black scale 
Hydrocyanic-acid gas. (See also Fumigation.) 
in drums 55 
Icerya purchasi, enemy of citrus fruits 11 
Insects, beneficial, used against citrus Bcalee in ( California 16 
Kerosene-water spray against citrus Bcales 
Lemon. (See Citrus.) 
Lepidosaphes beckii. v Scale, purple.) 
Mealy bugs, distribution in California J4 
enemies of citrus fruits 11 
Mite, rust, of orange. (See PhyllocopUs oh ivor us and Mite, silver, of Lemon. 
silver, of lemon. (See also Phyllocoptes < is.) 
sulphur spray as remedy 16 
