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GM Crops
SEARCA BIC October 2002

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 animals.

Why corn?

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 Bt corn.

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 Service(DA-BPI-PQS).

What happened in the public arena during the trial planting?

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 plowed again.

The process continued until May 2, 2000 with negative results for Bt gene checking. On May 10, 2000, the trial planting was declared complete.

What next?

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 environmental conditions.

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.”

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