Tomato farmers in Thailand used an extremely large quantity of
pesticides on average (42.5 kg/ha). The mean and median application
rates were 8 times greater than in Vietnam. On average, Thai
tomato farmers mixed 3.7 different pesticides in a single spray,
which is considerably greater than for the other countries. Such
high amounts of pesticide use in tomato production in Thailand
have also been reported from other recent surveys (e.g.
Schreinemachers et al., 2011; Riwthong et al., 2015). The fact that
60% of the Thai tomato farmers used fungicides against disease
with symptoms recognized by experts as being caused by plant
viruses highlights the difficulty of diagnosing diseases based on
symptoms alonedand also indicates there is a large gap in farmers'
knowledge about plant viruses. Virtually none of the Thai or Vietnamese
tomato farmers indicated that they used tomato varieties
resistant to some plant viruses, but 33% of the tomato farmers in
Tamil Nadu did. However, some of the grafted tomato plants purchased
by farmers in Vietnam may carry some virus resistance in
the scion. The use of protective gear was relatively advanced in
Thailand, as nearly all farmers covered most of their body during
pesticide spraying. However, in Vietnam and Tamil Nadu, farmers
tended to cover their mouths but probablywere unaware that some
pesticides penetrate the body through the skin, as they did not
cover their arms, legs, hands or feet.