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

Section 5 • Integrated Disease Management
Exercise No. 5.04 180
BACTERIAL OOZING TECHNIQUE: IDENTIFYING
BACTERIAL WILT DISEASE OF ORGANICALLY-GROWN
SOLANACEOUS VEGETABLES IN FARMERS’ FIELDS
BaCKGroUND aND raTIoNalE
Diseases of vegetable crops are caused by plant pathogens such
as virus, fungus, bacteria, and nematodes. For organicallygrown
solanaceous vegetables, the most destructive disease
caused by bacteria is bacterial wilt, commonly known as
kuyos. The disease initially causes partial wilting of plants.
The vascular tissue of main stem turns brown. The infected
tubers ooze through eyes or stolon end of tubers from
vascular ring of cut tubers. This bacterium is soil-borne
and can persist for many years. High soil temperature and high soil moisture favor the disease.
Unless farmers know how to determine which plant pathogen causes disease, they cannot employ
appropriate control or management approaches.
For farmers to determine if their fields are infected by bacterial wilt or other bacterial diseases, they
can adopt the bacterial oozing technique 181 . This technique can be used also to determine if other
bacterial diseases infect an organic vegetable field. In farmer field school (FFSs), this technique will
be a useful tool to aid farmers in their decision-making process, hence this exercise.
How long will this exercise take?
• Thirty minutes to one hour for field walks and observations of different solanaceous vegetable
diseases in learning field and adjoining organic vegetable farms; and
• Thirty minutes to one hour brainstorming session in processing area.
180 Adapted from Callo, Jr., D.P., L.B. Teofilo, and H.A. Tauli (eds). 2002. Field Guide of Discovery-based Exercises for Vegetable IPM, Volume II. SEAMEO
Regional Center for Graduate Study and Research in Agriculture (SEARCA), Los Baños, Laguna, Philippines. pp 223-225.
181 IIBC. 1996. Integrated Pest Management for Highland Vegetables, Volume 4: Training Guide for Participatory Action Towards Discovery Learning.
International Institute for Biological Control, BPI Compound, Baguio City, Philippines. pp106-107.
265
when is this exercise most
appropriate?
ɶ In FFS, TOT, and VST
sessions when there
are different vegetable
diseases that can be found
in learning and adjoining
fields; and
ɶ When farmers want to
learn practical tools to
identify bacterial diseases
in their own organic
vegetable fields.