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

Section 5 • Integrated Disease Management
Exercise No. 5.13 198
DEHAULMING AS A MANAGEMENT STRATEGY AGAINST
LATE BLIGHT DISEASE OF POTATO
BaCKGroUND aND raTIoNalE
Dehaulming is a cultural management strategy employed against
late blight disease of potato. The practice consist of defoliating
potato crop but leaving at least one foot of stem intact on tubers
that are kept in field with rows well hilled-up to prevent late blight
spores to get in contact with tubers. The tubers are not harvested
for at least two weeks after diseased foliage had been cut off to
allow time for spores to be washed off 199 .
The importance and economic value of this activity is highly
appreciated during and after harvesting of potatoes. It prevents
spread of late blight disease from foliage to tubers and allows production of disease-free seed tubers
for next planting season. Consequently, productivity is improved, production cost is reduced,
and higher profitability is achieved. In farmer field schools (FFSs), some innovative dehaulming
practices must be shared among farmers to improve their current best practices. The foregoing
exercise was designed to ensure participatory sharing of these best experiences.
How long will this exercise take?
• Thirty minutes to one hour field walks, observations, interaction with farmers, and hands-on
in learning field; and
• Thirty minutes brainstorming session in processing area.
learning objectives
• To create awareness and understanding among participants on the role of dehaulming as a
management strategy against late blight disease of potato; and
• To learn and do hands-on of dehaulming potato when late blight is observed before harvesting
in learning field.
198 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. pp256-258.
199 Milagrosa, S.P. 1998. As cited in: 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. 366p.
293
when is this exercise most
appropriate?
ɶ In FFS, TOT, and VST
sessions, when potato
crop is ready for
harvesting in learning
field; and
ɶ When organic
farmers want to learn
innovative dehaulming
practices from
other farmers as a
management strategy
against late blight
disease of potato.