Weed management: the broader context - Ecological Management of Agricultural Weeds - page 496

the outlook of the farmer, the extra labor requirements of ecological manage-
ment can thus be viewed either as an added cost or as a route for obtaining full
on-farm employment without expanding farm size (Lighthall, 1996). Some
farmers may consciously prefer to spend their workdays managing purchased
inputs on a larger farm rather than working with soil, crops, and animals on a
medium-sized farm. Many farmers, however, may be using chemical manage-
ment without careful assessment of all the trade-offs involved.
Farmers also perceive herbicides as low-risk solutions to weed manage-
ment. As all herbicide users know, applications sometimes fail to control
weeds to the desired extent for a variety of reasons related to weather,soil con-
ditions, timing of application, and equipment failure. Increasingly, however,
companies guarantee control by supplying materials for reapplication if
target control levels are not reached (Benbrook, 1996, pp. 47-9). For example,
Owen (1998) estimated that 25% to 30% of maize in Iowa was re-treated in
1994 through herbicide guarantee programs. Since aggressive marketing
gives growers the idea that weed-free fields are the only acceptable condition,
many second applications are probably unnecessary.In other cases,the second
application is untimely and the problem could be better solved through culti-
vation or use of an alternative chemical. Although respray programs are sup-
posedly free for the user, the costs are in fact paid for in the price of the
material. Nevertheless, such programs offer farmers a means for reducing one
of the risks associated with crop production. To the extent that respray pro-
grams foster unnecessary use of herbicides, however, they may increase risks
to human health and the environment.
Solving problems by selling products
Modern high-input mechanized agriculture co-developed with her-
bicide technology. A corollary of this co-development process is that most
growers receive little in-depth information concerning alternative
approaches.As noted in Chapter 1, information on chemical tactics has domi-
nated the weed science literature for the last 30 years. Consequently, the intel-
lectual underpinnings of modern weed management are closely linked and
largely limited to herbicide technology (Wyse, 1992). Additionally, large cor-
porations use well-financed advertising campaigns and extensive networks of
sales personnel to promote herbicides. In developing countries, promotional
campaigns include the free distribution of small quantities of herbicides and
other pesticides. Pesticides are advertised heavily in farm magazines
(Benbrook, 1996, pp. 164-5), whereas relatively few publications inform
farmers about how to manage weeds through the integrated use of cover