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

Section 6 • Simultaneous Insect Pest and Disease Management
Exercise No. 6.04 224
OVERHEAD IRRIGATION AS AN INSECT PEST AND
DISEASE MANAGEMENT STRATEGY IN ORGANIC
VEGETABLE PRODUCTION
BaCKGroUND aND raTIoNalE
In overhead irrigation, water is applied either in the form of
a fine mist (spraying) or spray simulating rain (sprinkling).
Water may be manually applied using watering cans or
mechanically applied under pressure and at pre-determined
intervals 225 . Experiences shared by farmers in previous FFSs
indicated that overhead irrigation is a cultural management
practice that plays a significant role in pest and disease
management in both conventional and organic vegetable production.
Overhead irrigation is suitable to dislodge spores of many fungus diseases (e.g., powdery mildew of
organically-grown garden pea, downy mildew of cabbage seedlings, rust of beans) from leaf surface
of infected vegetable crops, thereby minimizing disease infections. Likewise, overhead irrigation
reduces population of aphids, spider mites, white flies, and thrips in organically-grown crucifers,
legumes, and solanaceous vegetables.
Many farmers reported also that irrigating the field for at least eight hours using Jetmatic sprinkler (a
type of overhead irrigation equipment) disturbed adult DBM, a major insect pest of crucifers, thus,
minimized egg-laying capacity of female. These experiences and other organic farmer innovations
can be better shared to other farmers in FFSs through field walks and brainstorming sessions, hence
this exercise.
How long will this exercise take?
• Thirty minutes to one hour for field walks and observations of different irrigation practices and
equipment in adjoining organic vegetable farms of learning field; and
• Thirty minutes to one hour brainstorming session in processing area.
224 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 272-274.
225 Bautista, O.K. (ed). 1994. Introduction to Tropical Horticulture. 2 nd Edition. SEAMEO Regional Center for Graduate Study and Research in Agriculture
and University of the Philippines Los Baños, College, Laguna, Philippines. pp326-330.
333
when is this exercise most
appropriate?
ɶ In FFS, TOT, and VST
sessions, before doing an
overhead irrigation in
learning field; and/or
ɶ When farmers want to
learn the best experiences
from other farmers on
how overhead irrigation
minimize pest and disease
occurrence in their
organic vegetable fields.