Field Guide of Discovery-based Exercises for - Aseanipm ...

Section 4 • Integrated Insect and Rodent Pests Management
5 Majority of areas visited was planted to potato at varying growth stages (e.g., early,
mid-vegetative and later stages). Other vegetable crops (e.g., carrot, Chinese cabbage or
wongbok, cabbage, sweet and garden peas) were also planted. The effect of leafminer was
observed to be less serious, as exhibited by punctured but still appearing as green leaves,
at earlier stages and becoming more serious, as exhibited by drying of leaves or dying of
whole potato plants, at later stages. Heavily infested potato plant debris, alternate host
crops, and weeds are left undisturbed in all areas visited;
5 Interactions with farmers and extension workers suggested practice of continuous planting
of potato in those areas, without any fallow period, year in and year out. Likewise, they
indicated that this leafminer problem was first observed in Sitios Magmagaling, Lusong
and Salingao, Barangay Buyakawan, Buguias, Benguet and later in Sitios Mudayan and
Loo Proper, Barangay Loo, Buguias, Benguet. Farmers also said they observed that other
vegetable crops are also infested by leafminers. They said some crops were, however, more
susceptible (e.g., wongbok, celery and peas) than others (e.g., carrots and cabbage);
5 Extensive and indiscriminate spraying of pesticides were practiced throughout those areas
as evidenced by farmers spraying at the time of field visit and by the smell of pesticides
everywhere in areas planted to potato;
5 Interaction with farmers and extension workers indicated that many farmers have increased
their frequency of spraying against leafminer from every four days to every other day.
Likewise, they said some farmers have again cocktailed or mixed several pesticides as
spray materials against leafminer. However, farmers themselves confirmed that such
practice did not help contain this problem. In fact, they observed that leafminers were
unaffected by most of pesticides they have tried. There were also reports from them that
some farmers had started to use cyanide and formalin again but these did not help contain
this problem as well;
5 Several yellow sticky traps (e.g., made of different materials and shades of yellow colors)
were seen installed in many infested areas. Substantial number of adult leafminer catches
were also observed on these trap materials, with more catches on brighter yellow shades ;
and
5 Interaction with farmers showed that among several non-pesticide control strategies
introduced in those areas, so far, only these yellow sticky traps worked. It was also interesting
to note many innovations shared on the use of yellow sticky traps during interaction with
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