The Panama disease caused by a soil-borne fungus is threatening banana crops across Kerala, posing a potential crisis for farmers, even as global efforts to control the disease gain momentum.
Agricultural scientists are concerned that the sporadic cases of infestation in the State would turn into an epidemic.
Most of the popular cultivars including Poovan, Nhalipoovan and Nendran have shown signs of infestation. Scientists at Kerala Agricultural University recommend soil treatment with fungicides for control of the disease but they are worried that farmers who are yet to recognise the enormity of the threat would ignore the need for intervention.
Also called Fusarium Wilt of banana, Panama disease is caused by the soil-borne fungus Fusarium oxysporum f . sp. Cubense (Foc).
The fungus enters the plant through the roots and goes on to colonise the plant through the vascular system, blocking the flow of water and nutrients.
It causes discoloration and wilting of the leaves and eventually kills the plant.
The fungus is spread through infected planting material, soil and water. The fungal spores can persist in the soil for decades.
During the 1950s, Panama disease wiped out the Gros Michel banana, the dominant cultivar.
Over the years, it spread from Panama to neighbouring countries. A new virulent strain of the disease known as Tropical Race 4 (TR4) is now threatening banana crops in Asia, Australia, Africa and the Middle East.
“The disease is yet to assume epidemic proportions in Kerala but if left ignored, it could lead to a crisis,” says C. Gokulapalan, former Professor, Plant Pathology, KAU. The acidic soil in the State is conducive to the fungus.
“The symptoms appear only in the yield stage when the bunches have emerged. This often forces farmers to ignore the signs fearing huge loss,” he says.
“Fusarium Wilt is largely confined to wetland cultivation where waterlogging provides a conducive situation for the fungus to invade plants,” says K. Uma Maheswaran, Professor, Plant Pathology.
Blaming the practice of monocrop cultivation for the situation, he advocates regular crop rotation to manage the disease.
Scientists attending the International Banana Congress which concluded in Miami on April 23 reported on the search for new banana varieties resistant to the Fusarium fungus.
Steps to check the spread of the disease were on the agenda.