TABLE 1.--Approximate number of noninsecticidal pesticides in use in various years, 
1800 - 1960 
= ire 
Year 
Number Number Number Number Number Number 
1800 2 fe) @) 6) O O 
1850 2 ) 0) 0 O 0) 
1900 4 4 al 5 1 10) 
1920 th 4 2 6 1 O 
1930 9 4 3} 8 3 1) 
1940 ) 29 3} 8 6 4 
1945 2 Zi 3} 9 10 7 
1950 9 33 6 9 22 9 
1955 9 B35 8 10 38 12 
1960 £ 36 12 10 Dif 16 
Before 1940 protectant fungicides were almost exclusively inorganic. Subsequently, 
use of inorganic fungicides, with few exceptions, dropped as they were replaced by such 
organic materials as the dithiocarbamates, quinones, and s-triazines (figure 1). A similar 
situation developed with herbicides although large tonnages ofinorganics such as chlorates, 
borates, and arsenicals are still used on noncrop areas. Synthesis and evaluation of new 
herbicides and growth regulators are currently expanding rapidly, but the rate of intro- 
duction of additional fungicides appears to have leveled off. 
300 
250 
200 
150 
100 
MILLIONS OF POUNDS 
50 
1925 1930 1935 1940 1945 1950 1955 1960 
YEAR 
BN-10806-X 
Figure 1,--U, S, Production of copper sulfate for fungicides in years, 1926-1957. 
(From Agricultural Statistics, U, S, Department of Agriculture.) 
19 
