In agriculture R&D, the last quarter of 1999 was highlighted
by a barrage of protests against conducting the first field
trial of Bt corn in the Philippines. Congressional resolutions
were made and marathon hearings were held to allow both sides
of the issue a chance to air views for or against genetically
modified organisms or GMOs.
GMOs are products of genetic engineering that allows the transfer
of a specific gene within the organism or from one organism
to another. Genes are hereditary materials that are responsible
for the expression of traits like a person’s eye color
or a fruit’s taste.
What makes a Bt corn a GMO?
Bt corn is a GMO because a certain gene, from a naturally-occurring
soil bacterium Bacillus thuringiensis(Bt) var. kurstaki, was
transferred to corn. This gene codes for the production of a
specific protein called delta-endotoxin protein which when eaten
by a specific target insect such as the corn borer and other
lepidopteran pests, makes the insect ill and die. Thus, a Bt
corn plant produces the killer protein. Remember, it affects
only specific target insects.
Why corn borers are pests?
Corn borers are highly damaging pests of corn. They eat the
leaves, bore into the stems and ears of corn, and eat the seeds.
The feeding damages the leaves and the numerous entrance holes
that borers make not only turn the plants ugly, but, destroy
the plants’ vital life processes such as its food manufacturing
system called photosynthesis and the nutrient transport system
. Stems become soft and easily broken, too. Because of the injuries
caused by corn borer, plant disease causing organisms such as
fungi and bacteria can readily come in and attack the corn plants,
making them sicklier than ever. Most popular among these is
the aflatoxin-producing fungi that cause cancer. These fungi
find its way into the corn seeds fed to our livestock and poultry
So why do we bother about corn? Because next to rice, corn
is a major economic crop in the Philippines. Its total annual
production is valued at more than P20B. It is consumed as food
by 20% of the population. But, the major user of corn is the
feed industry which absorbs 70% of total corn production. The
country has been increasingly importing corn in the last 10
years at the rate of 9.8%. This implies that local corn production
is insufficient to meet the industry’s demands.
One of the major limiting factors in corn production in the
country is the heavy infestation of Asiatic corn borer, Ostrinia
furnacalis Guenee. In the Philippines, a 30-40% reduction in
yield have been observed due to this pest. Studies by Sanchez,
1971 and Rejesus, 1983 recorded a yield reduction ranging from
20-80%. In a survey conducted during the 4th quarter of 1999,
the Office of the Provincial Agriculturist in South Cotabato
estimated a yield loss of about 30% valued at P118M. Thus, there
is a need to develop and test other control measures that would
be complementary to existing integrated pest management strategies
for corn borer. One such option is the Bt corn technology where
farmers no longer need to apply expensive chemical pesticides
that are currently being used to control the corn borers.
Is Bt corn new?
The Bt corn is not a new GMO product. It was developed as early
as 1986, and in 1996, the United States has started growing
Bt corn in commercial scale. Canada, Argentina, and China followed.
Today, about eleven(11)M hectares are commercially planted with
Why test Bt corn in the Philippines?
Since GMOs are products of new technologies which might have
potential risk to human health and the environment, GMOs undergo
several rigorous trials both under contained facilities and
planned releases prior to commercialization. These trials ensure
that GMOs deliver its claims and safety concerns have been adequately
addressed. The Bt corn variety to be introduced in the Philippines
is highly effective against European corn borer (ECB), Ostrinia
nubilalis. However, a different species is found in the Philippines
which is known as Ostrinia furnacalis Guenee or the Asiatic
corn borer(ACB). Although, the ACB is biologically and taxonomically
related species of ECB, there is a need to know whether the
Bt corn is also effective against ACB.
Who were behind the Bt corn trial planting?
With approval from the National Committee on Biosafety of the
Philippines (NCBP), the agency tasked by government to oversee
biotechnology research in the country, Fernandez et al (1997)
conducted studies under contained facilities to test the efficacy
of Bt corn hybrids. These studies revealed that Bt corn was
effective against ACB. Encouraged by these results, the Institute
of Plant Breeding, University of the Philippines Los Banos and
the Agroseed Corporation which developed the Bt corn varieties,
in collaboration with the International Service for the Acquisition
of Agri-biotech Application (ISAAA) applied a permit in 1998
to conduct a limited field trial. The movers behind the proposed
trial were researchers of the Institute of Plant Breeding-University
of the Philippines Los Banos (UPLB), namely, Dr. Eduardo C.
Fernandez, PhD in Entomology/Host Plant Resistance and Dr. Violeta
N. Villegas, PhD in Plant Breeding and a collaborating scientist
from Agroseed Corp., Dr. Manuel L. Logrono, PhD in Plant Breeding/Host
Plant Resistance. After almost a year of thorough evaluation
of the proposed trial, the NCBP finally gave its blessing for
the first-ever field trial on August 25, 1999. The objectives
were to determine the efficacy of Bt gene against ACB under
field conditions and to generate initial data on the performance
of Bt corn as compared with non-Bt corn hybrids and local varieties.
The field trial was to be conducted in a 500 square meter lot
in the Agroseed Research Station, Lagao, General Santos City.
How was the field trial conducted?
Amid the brewing debates and media hype, the trial started
on December 15, 1999. To ensure adequate testing of the efficacy
of the Bt corn, natural infestation of corn borer was augmented
by artificially infesting about-to-hatch corn borer egg mass
to each plant. Also, in consideration of the concerns of those
opposing the trial, the scientists undertook additional procedures.
These include detasseling (removal of the male flower) and installation
of a 10-foot artificial barrier as an additional measure to
prevent pollen flow from the experimental plants to neighboring
fields. Monitoring of beneficial insect profile and soil arthropod
sampling were done in the trial site as well as outside of the
trial site. These activities were monitored by the members of
the Institutional Biosafety Committee (IBC), the NCBP, and the
Department of Agriculture- Bureau of Plant Industry-Plant Quarantine
What happened in the public arena during the trial
Meanwhile, efforts to stop the trial were launched. The anti-GMO
advocates filed petitions to the local government unit, the
House of Representatives, the Senate and the Supreme Court to
halt the trial. These resulted to congressional resolutions
and senate bills, some of which are anti-biotech and anti-science
in stance. Later, the Supreme Court dismissed the petition for
lack of merit. Amid threats of unauthorized uprooting of plants,
the trial pushed through. (Note: The Senate Agricultural
Committee through its Report No. 397 dated September 8, 2000
has nixed the proposed ban on genetically improved crops).
The debates brought to fore the gap in public understanding
of modern biotechnology and GMOs. The scientific community was
called upon to shed light on this new technology. On some occasions,
scientists are subjected to allegations of being in cohorts
with the multinational firms. As scientists built its capacity
in becoming effective public information officers, more and
more government and international research agencies and academic
institutions organized biotechnology information awareness activities.
These activities also provided opportunities to discuss the
merits and demerits of GMOs.
What were the results of the trial planting?
Finally on March 18, 2000, the Bt corn plants were ready for
harvest. Representatives from NCBP, IBC, BPI-PQS, farmer-groups,
academe, non-government organizations and government agencies
came to witness the harvesting. These representatives saw the
promising results of the trial planting.
The Bt corn hybrids showed high resistance against the Asiatic
corn borer. The corn borer larvae failed to establish in the
Bt plants, thus, the leaves and stems were undamaged. The non-Bt
corn plants, however, showed visible leaf and stalk feeding
damage. The Bt corn ears were also clean and no secondary fungal
rot infection occurred unlike the non-Bt corn ears. This could
mean safer food and feed products and better market price. With
more healthy ears being harvested, yield of Bt hybrids was higher
as compared to the non-Bt entries.
Yield difference between the Bt and non-Bt hybrids ranged from
1.6 to 3.4 tons/ha, or a yield increase from 30 to 69%. Beneficial
insects such as spiders, coccinelid beetles and green lacewings,
as well as soil arthropods were found abundant both in Bt and
non-Bt plots indicating that Bt did not affect non-target organisms.
Corn aphids, another corn pest that like to eat healthy plants,
were also abundant in the Bt plots. This suggests that aphids
were not affected by the Bt protein and showed the high specificity
of the protein.
These promising results clearly showed the potential benefits
of the Bt corn through increased in yield, production of higher
quality and cleaner grains and the possible elimination of the
use of chemical insecticides to control the borer.
The safety of the Bt gene and its product to the environment
is a scorching issue in GMO debates. The NCBP took extra steps
to ensure that concerns of non-GMO advocates on possible escape
of Bt gene to the environment shall be addressed before, during
and after the trial planting despite the empirical data from
abroad that such did not occur. Thus after harvesting, the proponents
burned all the plants inside the test area, plowed the field
under, then, flooded it. Plants that germinated after flooding
were tested for the presence of Bt genes, then, the field was
The process continued until May 2, 2000 with negative results
for Bt gene checking. On May 10, 2000, the trial planting was
The first Bt corn field trial was completed but the story is
not yet over. With the encouraging results of the limited field
trial, the proponents recommended and applied permit for a multi-location
field trials to further test the efficacy of Bt corn in different
With the increasing public understanding on GMOs and the anticipated,
renewed anti-GMO campaign, may its discussion be “carefully
followed through openness, analysis and controls, but, without
a sense of alarm.”