194 Agroecology and Sustainability
In Cambodia and Laos, labelling of pesticide products is often inappropriate as
labels are usually in foreign languages (Thai, Vietnamese). This situation is aggra-
vated by high illiteracy rates in the rural population. Original products are often
repackaged and contain no label at all (EJF, 2001). For example, a recent study
conducted in Cambodia revealed that only 8 of 77 pesticide traders said they could
read foreign labels on pesticides they sold, whilst 97.5 per cent of the pesticides
were labelled in a foreign language (CEDAC, 2000). The extensive use of synthetic
pesticides results in a range of unsustainable production practices arising from
undesirable externalities. The frequent applications of pesticides most often causes
resurgence of pest populations because of the destruction of natural enemies.
Resistance of target pests against pesticides has become a serious problem for many
important vegetable pest problems, such as diamond back moth (Plutella xylos-
tella) on crucifers and fruit and shoot borer (Leucinodes orbonalis) on eggplants.
However, greater awareness among consumers in urban communities of the
dangers of pesticide residues on vegetables has created a growing demand for veg-
etables free of residues. Governments in many developed Asian countries have now
established maximum residue levels (MRL) regulations for pesticides on imported
vegetables. Clearly, the consequences of international trade restrictions related to
residues of toxic pesticides on vegetable produce can no longer be ignored. None-
theless, vegetable production in tropical and subtropical Asia remains in a ‘crisis
phase’ (Lim and Di, 1989; Shepard and Shepard, 1997), requiring urgent atten-
tion to safeguard the production of healthy food and producers’ livelihoods across
Asia.
Vegetable IPM: Ecosystem Considerations and the Need
for ‘Informed Intervention’
What is it that drives the frequent use of pesticides in intensified vegetable produc-
tion in most of Asia? The main factors seem to be the high risk of crop losses, the
acute occurrence of serious crop pests, and the heavy promotion of pesticide use by
the private sector. In addition, the low level of ecological literacy and wider low
level of education of farmers, particularly in a country like war-ravaged Cambodia,
further explains the rampant use of pesticides. However, it is important to under-
stand that there are some major differences between the need for human interven-
tion in ecosystem management when comparing vegetables to rice in tropical
Asia.
While many locally consumed vegetables are native to tropical Asia, most veg-
etables produced in Asia for local consumption and for market supply are exotics.
Many popular cash crops such as tomatoes, crucifers, potatoes were relatively
recently introduced to Asia from temperate regions. Similarly, many important
pest and disease problems are exotic, such as the diamond back moth, which was
introduced from Europe into Asia without its naturally existing complex of natural