DAVAO CITY—The viral strain, known as the Panama disease, that’s attacking the cavendish bananas in a Davao del Norte town is one of the most virulent strains of the Tropical Race viruses and banana growers warned authorities that lack of adequate scientific control and failure to contain the threat could wipe out the industry.

The Pilipino Banana Growers Exporters Association (PBGEA) said it was dismayed by the initial lukewarm reaction of the Department of Agriculture but expressed appreciation for the recent directive of Secretary Proceso Alcala to create a task force to control the threat.

Stephen Antig, executive director of the PBGEA, told the  BusinessMirror that agricultural scientists had already monitored the TR4, or the Panama Disease, as the one attacking cavendish bananas in isolated farms in Davao City and Compostela Valley as early as 2006, although some studies showed this also happened in some Mindanao farms as early as 2002.

“This is the most virulent of the Tropical Race viruses, this TR4, and we are deeply concerned with its occurrence in Santo Tomas town, not only because it threatens the livelihood of small farmers but because it has the potential to wipe out the industry,” he said.

The TR4 is soilborne and attacks the roots. Available research indicates that the virus attacks bananas and tomatoes. In the case of bananas, the leaves turn yellow as the first outward manifestation of the attack.

“By then, it would be too late,” he said, “as all leaves would then wilt.”

The Panama disease, also called Fusarium wilt disease, is caused by Fusarium oxysporum f. sp. Cubense or Foc. According to study by six Filipinos presented during the Centennial Meeting of the American Phytopathological Society in July 2008 in Minneapolis, Minnesota, the Fusarium wilt disease “wiped out” the Gros Michel plantations in Central America in the 1950s and “consequently caused a costly shift” to the cavendish variety.

“To date, cavendish remains resistant to the Fusarium strain that prevails in Central America. However, a virulent strain that can attack the cavendish was found causing epidemics in Asia. Known as Tropical Race 4 [TR4], this pathogen destroyed commercial plantations of cavendish in Taiwan, Northern Territory of Australia, Indonesia, Malaysia and China making their banana exports less competitive,” the paper said.

For many years, TR4 has not been found in the Philippines, contributing to its dominance in the export banana trade in Asia, it said. But in 2002, a new strain appeared in a highland cavendish farm in Mindanao.

From 2004 to 2005, new incidences of Foc infections were observed in some traditional lowland commercial cavendish farms, the report said. “Although occurrences of Fusarium wilt disease have been reported in cavendish farms between the period of the 1970s and the 1990s, these were associated with a less virulent strain of Foc. These previous incidences never became significant constraints to production,” it added.

Antig said the TR4 attacks were noted in 2006 in small and scattered banana farms in Calinan district, Compostela Valley,  and Bukidnon, “but destroying only a small area.”

The PBGEA said it was alerted only in September this year when small growers asked the Santo Tomas town officials to look into the wilting of their bananas.

In at least two public hearings in Santo Tomas town, the PBGEA has already appealed to the farmers and farm technicians to observe the minute details of containing its spread to the other farms. This includes not allowing the entry and egress of persons and animals because contaminated soil may stick to the shoes and feet; not allowing cutting of the trunks because the virus are likely to stick to the bolos and when used in other farms would spread the diseases; and to quarantine the area by burning the soil around the affected plants.