Tropical Race 4 (TR4), the virulent strain of fungus Fusarium oxysporum cubense that is threatening banana crop globally with the fusarium wilt disease, has hit the plantations in India, the world’s top producer of the fruit. The devastating disease which surfaced in the Cavendish group of bananas in parts of Bihar is now spreading to Uttar Pradesh, Madhya Pradesh and even Gujarat, and threatening to inflict heavy losses to the country’s ₹50,000-crore banana industry.

Alarmed over the spread of the disease, farm policymakers are expected to discuss control measure with various States to curb the spread of the pathogen at the forthcoming National Conference on Agriculture for Kharif Campaign later this week, sources said.

India is the largest producer of banana and accounts for 29.1 per cent of the global output. The country’s output is estimated at around 30 million tonnes from an area of 0.80 million hectares.

TR4, the soil-borne pathogen infests banana plants with the fusarium wilt disease through the roots that spreads to the vascular system and blocks transportation of water and nutrients in the stem, resulting in yellowing of leaves and plant death.

Low awareness

Sources said the fusarium wilt pathogen persists in soil for decades and is extremely difficult to manage.

The disease had initially surfaced in the Katihar and Purnea districts of Bihar in 2015 and had spread to Faizabad district of Uttar Pradesh last year and now to Burhanpur district in Madhya Pradesh and Surat in Gujarat. However, details of total acreage affected hit by the disease were not available.

In India, most of the farmers use suckers as planting material and are not aware of the serious nature of TR4 in banana. The incidence of Fusarium wilt will increase in the years to come said an agenda note on kharif conference. As the banana bunches are transported to various States, the pathogen can spread through peduncle of the bunches and there is a chance for the spread of this virulent TR4 strain to other States as well.

“Therefore, creation of awareness and providing training to all the stakeholders on the importance and identification of Fusarium wilt disease, preventive steps to be taken to arrest the further spread of the disease to the uninfested areas in Bihar,” it said.

‘Burn affected plants’

The National Research Centre for Banana, under the Indian Council for Agricultural Research, has begun advocating of burning disease-hit plantations in the affected regions. In collaboration with the State agriculture departments, it is exhorting banana farmers to take up crop rotation and growers are seen shifting to maize and paddy in Bihar among other States.

Though more than 20 varieties of banana are grown commercially in India, the trade mainly depends on the Cavendish clones that include Grand Naine, Robusta, Bhusaval, Basrai and Shrimanthi among others.

Cavendish variety affected

The Cavendish clones, which account for 55 per cent of the total area and contribute to around 64 per cent of the total output, are highly susceptible to the fusarium wilt disease.

The Cavendish cultivars globally have succumbed to the TR4 race in many producing countries including China, Taiwan, the Philippines, Indonesia, Malaysia, Australia, Pakistan and, most recently, in Jordan, Mozambique and Vietnam.