(Yicai) June 14 -- Almost 80 percent of the betel nut trees in Wanning, one of China’s largest betel nut growing areas, have been struck by a viral disease, forcing local farmers to find other sources of income.

Around 420,000 mu of betel nuts, equivalent to 28,000 hectares, have been affected, accounting for 78.7 percent of the planting area, Fu Xiqiang, head of the Wanning betel nuts association in southern Hainan province, told Yicai.

Known as a ‘yellowing disease,’ the blight causes the roots to rot, turns the leaves yellow and prevents the tree from blooming and bearing betel nuts, Yicai learned. The nuts fall from the tree before they are ready.

At first, farmers tried to control the spread of the disease by cutting off the yellow leaves, fertilizing more, installing intravenous drips and spraying pesticide with drones but to little effect.

As a result, output has plunged. Wanning is producing less than 250 tons of fresh betel nuts a day at the moment, a fraction of the 5,000 tons a day it used to produce in bumper periods, Fu said. The annual yield tumbled to 56,400 tons in 2020 from 220,000 tons in 2014.

Around half the city’s population has been affected. Betel nut production accounted for half of the municipality’s economic output in 2021 at CNY14 billion (USD1.9 billion), and its processing value was CNY7.7 billion (USD1.1 billion). In 2022, the processing value was CNY7 billion, according to a local government work report.

As local farmers start to lose their main source of income, they are being forced to turn to other crops, such as passion fruit and litchi, but these come with their own set of challenges.

A farmer who planted litchi trees only made profit of between CNY2,000 (USD276) and CNY3,000 last year and he is set to earn even less this year. And passion fruit is very vulnerable to changes in the weather, so it will take time to reach the same scale as a betel nuts plantation, he added.

Editors: Zhang Yushuo, Kim Taylor