3.3. Farmers' knowledge and perceptions of plant viruses
Asked what could be the cause of these disease symptoms, most
farmers in Thailand and Vietnam were unaware that these were
caused by a virus.
Of the Thai chili farmers, only 8% identified the
problem as caused by a virus, whereas in Tamil Nadu, 49% of tomato
and 58% of chili farmers were aware that the disease symptoms
were caused by a plant virus.
Private seed companies and government
extension services in Tamil Nadu, India have been active in
educating farmers in this respect, while no such activity was conducted
in the other countries.
Very few farmers in Thailand and Vietnam knewthat insects can
transmit plant viruses.
In tomato production, only 16% of the Thai,
0% of the Vietnamese, and 31% of the Tamil Nadu farmers associated
the spread with whiteflies, thrips or aphids.
In Tamil Nadu farmers have started using certain biopesticides
claimed to be effective against virus diseases.
In some cases they
mixed the biopesticides with synthetic pesticides (such as monocrotophos
or imidacloprid), although government extension services
and agricultural departments do not recommend this.
Private farm magazines also
publish numerous articles in local languages vociferously advocating
the use of biopesticides against plant viruses, without proper
scientific studies.
Government agencies (agricultural and horticultural
departments) provide no practical solution other than
uprooting and destroying virus-infected plants.
The farmers tend to
rely upon the input dealers and their suggestions.