HERBICIDES in Asian rice - IRRI books - International Rice ...

as more lucrative, full-time job opportunities become available in nonagricultural activities,
Asian farmers are finding it increasingly difficult to hire seasonal workers for
transplanting and hand weeding rice. The current movement of labor from agricultural
to nonagricultural sectors in the less developed countries of Asia is characteristic
of a more general process of structural transformation that occurs at varying rates and
degrees in all developing economies. The process is defined broadly by a diminishing
role of agriculture in national income and aggregate employment as an economy grows.
A relative decline in the agricultural labor force occurs in the early to middle stages of
structural transformation; in later stages, the absolute number of workers in agriculture
also falls (Timmer 1988). The process of structural transformation is already well
advanced in several Asian countries (Table 1).
One consequence of this structural transformation is that, in many Asian countries,
real wages for agricultural labor have increased relative to real rice prices (Table
2). In 1995, the world price of rice, adjusted for inflation, was roughly half what it
was in 1970 (World Bank 1996). In a number of regions, that higher cost-to-return
ratio has induced the adoption of herbicides as a substitute for hand weeding
(Table 3).
Herbicides offer one of the most effective means by which rice farmers can reduce
labor costs for two reasons. First, labor inputs for hand weeding are extremely
high, accounting for up to half the total preharvest labor hours in some irrigated rice
systems of Asia (Naylor 1994a). Second, effective use of herbicides permits direct
seeding of rice, which further economizes on labor. Experimental data from IRRI
show that labor costs average 1.8 person days per hectare for direct-seeded rice and
Table 1. Economic indicators for selected Asian countries, 1965-90.
Country
Annual GNP
GNP from
Labor force
growth (real) agriculture (%) in agriculture (%)
GNP capita -1
1990 1965-80 1980-90 1965 1990 1965 1990
Nepal
Bangladesh
India
China
Pakistan
Sri Lanka
Indonesia
Philippines
Thailand
Malaysia
Korea, Rep.
Singapore
Hongkong
Japan
170
210
350
370
380
470
570
730
1,420
2,320
5,400
11,020
11,490
25,430
2.3
2.4
3.8
6.4
5.2
4.0
7.9
5.9
7.4
7.3
9.5
10.2
8.5
6.3
4.6
4.3
5.3
9.5
6.3
4.0
5.5
0.9
7.6
5.2
9.7
6.4
7.1
4.1
65
53
47
39
40
28
56
26
35
28
39
3
2
9
60
38
31
27
26
26
22
22
12
na
9
0
0
3
94
84
73
81
60
56
71
58
82
59
55
6
6
26
92
68
66
68
50
52
48
47
64
32
24
0
0
6
Sources: World Bank, various issues; IRRl (1995); UNDP (1990).
4 Naylor