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

Section 5 • Integrated Disease Management
Exercise No. 5.14 201
USE OF BENEFICIAL MICROORGANISMS IN MANAGING
SOIL-BORNE DISEASES OF ORGANICALLY-GROWN
VEGETABLES
BaCKGroUND aND raTIoNalE
In soil, many microorganisms live in close proximity and
they interact in a unique way. The use of beneficial soil
microorganisms for biological control of soil-borne plant
pathogens is possible only if such interactions between species
as competition, amensalism, and parasitism or predation
occur. Competition is a condition where there is a suppression
of one organism as two species struggle for limiting quantities
of nutrients, oxygen, or other common requirements.
Amensalism, on the other hand, occurs when one species is
suppressed while a second is not affected, typically a result of
toxin production, while parasitism or predation refers to direct attack of one organism on another 202 .
In organic vegetable production, use of a soil fungus, Paecilomyces lilacinus (commercially known
as BIOACT) as parasite of Meloidogyne incognita (root knot nematode) or as competitor of another
soil fungus, Plasmodiophora brassica (clubroot), is a typical example of a beneficial microorganism
used to control a harmful microorganism 203 . Such practices as soil incorporation of guano and
organic matters to increase soil pH will drastically reduce population of harmful soil microorganisms
in favor of beneficial ones 204 . In farmer field schools (FFSs), some innovative farmers can share their
experiences in using useful soil microorganisms to improve current practices in managing soilborne
diseases of organically-grown vegetables. This exercise is meant to address this particular
concern.
201 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. pp253-255.
202 Alexander, M. 1977. Introduction to soil microbiology. 2 nd Edition. John Wiley and Sons, Inc., New York, USA. pp405-437.
203 Davide, R.G. 1990. Biological control of plant pathogens: progress and constraints in the Philippines. Phil. Phytopath. 26:pp1-7.
204 Callo, Jr. D.P. 1993. Recent Development on the Utilization of Soil Microorganisms for Biological Control of Plant Pathogens. Term paper submitted in
partial fulfillment of the requirements for Advance Soil Microbiology, Institute of Graduate School, Gregorio Araneta University Foundation, Malabon
City, Philippines. pp11-12.
297
when is this exercise most
appropriate?
ɶ In FFS, TOT, and VST
sessions, as component
of topic on ‘Integrated
Disease Management’;
and
ɶ When organic
farmers want to learn
from others some
innovative practices
in using beneficial
soil microorganisms
for management of
vegetable diseases.