80 FUMIGATION METHODS 
judgment regarding the dimensions of the trees to be 
fumigated, a stick marked off in feet will be of assist- 
ance. 
QUANTITY OF CHEMICALS TO DESTROY BLACK SCALE ON 
CITRUS TREES 
HIGHT Diameter Water Sulphuric Acid Cyanide 
Feet Feet Ounces Ounces Ounces 
6 4 ‘ 146 
8 6 5 14 14 
2 10 2 3 ing 
12 0 
12 14 18 416 416 
14 14 20 5 5 
16 16 24 54% 5% 
18 16 24 6 6 
20 16 26 616 616 
22 i 30 4 714 
24 20 32 8 
26 20 33 84 814 
30 20 35 816 816 
The proportions of chemicals used for citrus trees 
affected with red, brown, or purple scale are given in 
the following table. ‘The same quantity may be used 
for deciduous trees infested with San José or black 
scale. 
CHEMICALS FOR RED, BROWN, AND PURPLE SCALE 
HIGHT Diameter Water Sulphuric Acid Cyanide 
Feet Feet Ounces Ounces Ounces 
6 4 3 34 34 
8 6 M4 1% 1% 
10 8 94 3 3 
12 10 3 416 414 
12 14 27 634 634 
14 14 30 av ub Z 
16 16 36 814 814 
18 16 36 9 9 
20 16 39 934 934 
22 18 45 10% 10% 
24 20 48 12 12 
26 20 4916 1234 1236 
