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

198
Field Guide of Discovery-based Exercises for Organic Vegetable Production
farmers. For instance, some claimed that better result was obtained when each plant was
installed with yellow soft drink straw dipped in grease oil. Others confirmed effectiveness
of using yellow flaglets with grease oil to sweep adults as we have observed in potato field,
which they said complemented these installed yellow traps.
2. Go back to processing area, brainstorm in small groups, and present output to the big group.
Conduct participatory discussion to allow sharing of experiences among participants and
facilitators. Motivate farmers to share their best experiences in controlling potato leafminers
using different yellow sticky trap materials.
3. Synthesize and summarize output of small groups into one big group output. Draw up
conclusions and recommendation from this exercise. For example, based on field observations
and interactions with officials and farmers in Buguias, Benguet, the following conclusions and
recommendations were made 141 :
5 The leafminer infesting potato in Barangays of Buyakawan and Loo, Buguias, Benguet
is probably Liriomyza huedobrensis (Diptera: Agromyzidae) which was also reported
infesting potato in other Southeast Asian countries (e.g., Indonesia, Malaysia, and Thailand).
5 Based on progressing appearance and severity of symptoms observed in the field, it appears
that an adult leafminer (smaller than a rice whorl maggot adult) will choose a younger
potato plant for oviposition. Thus, newly hatched larvae will be too small to see with naked
eyes at earlier crop stage and a progressing severity of damage will be more visible together
with larger larvae as the crop grows older.
5 The indiscriminate use of pesticides had apparently resulted in the development of
pesticide resistance by this pest as shown by the absence of dead leafminers in the field
after pesticides spraying were conducted. It likewise resulted to elimination of natural
enemies, particularly predators and parasites, as shown by their absence in the field.
5 The practice of continuous and asynchronous planting of potato as well as planting of
alternate host crops, such as Chinese cabbage and celery, by farmers provided year-round
host and uninterrupted reproduction for leafminer. This is aggravated by the improper
disposal of infested potato plant debris as well as alternate host crops and weeds.
5 While the use of yellow sticky traps is more effective than spraying pesticides and is well
accepted as a non-pesticide control strategy against leafminer, its sustainability hinged on
141 Callo, Jr., D.P. 2000. Travel report of leafminer infestation in Buguias, Benguet from 05-08 January 2000. ASEAN IPM Knowledge Network Center,
SEAMEO Regional Center for Graduate Study and Research in Agriculture, College, Laguna, Philippines. pp2-5.