To identify the perceived pest and disease problems, farmers
were given a stack of photographs of the most common pests and
diseases as suggested by various experts and had to select the
photographs of symptoms and pests that they recognized from
their field. Each photograph depicted one pest or disease. We used
32 photographs for tomato, 21 for chili and 23 for mungbean as
each crop is affected by a different number of pests and diseases.
The photographs came from ourselves, from colleagues and from
Internet websites of various organizations dealing with crop protection.
Therefore, the resolution was not the same for each
photograph. Photographs of insect pests included both the insect
and the damage it causes, while for plant diseases the photographs
showed only the damage symptoms. The complete list is included
in the Annex and the photograph tool will be shared upon request.
We included photographs of all possible pests because yield losses
due to plant viruses are likely to be overstated if only photos of
virus diseases are presented, which is a limit of previous studies