86
180
120u)
U
0
c
0
5 100a
f 80I
._
6 0 :
.lo-;,
2 0
0 ,
dj, , , , , , / . ; - I
= 4
- 3
1
> 2
1910
1920
1930
1940
1950
1960
I
. I
a ,
a .
, .
I
S
I
.
I
.
,
I
*
I
, .
, .
, .
i
*
I
*
*
,
I
$
0
I
*
,2.4-l
i
, a
I *
,:
-
\
- \
I
1940
1945
1950
1955
1960
Date
FIG. 1. The increasing use of herbicides in Britain - the progress of rheinical weed control
in cereals 1911-65. After Woodford, 19G4. Note: Total acreage in 1963 = 7.934 million
acres (3.172 million ha.).
FIG. 2. Changes in the productioii of pesticides in the U.S.A. 1939-63. (Data from
agricultural statistics, USDA. U.S. Government Printing Office, Washington.)
Note: The graphs for the inorganic insecticide lead arsenate, the synthetic organic
insecticides DDT and dieldrin, and the synthetic organic herbicide 2,4-D are of production. Not all the pesticides produced were used in the U.S.A. I n 1963 101 955 000 lb
of DDT, 803 000 lb of lead arsenate and 28 GOO 000 lb of herbicides inr.luding soine
2,4-D were exported.
The graph of pyrethrum, an insecticide dwived from t,he plRnt C'li,!/suntl~e,,,ui,1
cineruriuefolium, is of imports.
Earlier figures for dieldrin not availablc: it, was first, produced about 1950. 1963 figure
for lead arsenate not available.