Vietnamese farmers should not wait for their durian to be rejected by China

Nearly 70% of the 900 farming households In Ha Lam Commune in Lam Dong Province's Da Huoai District have become wealthy thanks to the fruit.

Last year a "100 Billionaire Farmers" Club, made up of those earning in the billions of dong annually from durian, was launched.

But this year that joy has faded.

Unfavorable weather caused widespread nutritional shock to the trees, halving the fruit-setting rate compared to the previous year. Besides, durian prices have dropped sharply.

Farmers are now facing a double blow: reduced yields and prices down by two-thirds.

Durians are harvested in Tien Giang Province in southern Vietnam. Photo by VnExpress/Hoang Nam

Vietnam's durian exports hit a record US$3.2 billion in 2024.

But the business is getting tougher with its biggest buyer, China.

Since official exports to China began in September 2022, more than 30 shipments have been flagged by Chinese customs for containing cadmium, a toxic heavy metal.

Chinese authorities also raised concerns about the presence of yellow O, an additive banned for its cancer risk.

The giant market now requires 100% of shipments to have certificates proving the absence of cadmium and yellow O before clearance.

As a result shipments are piling up at the border and inspection systems are overloaded, but fresh durian cannot wait. Farm-gate prices have plummeted from VND120,000 ($4.63) per kilogram to as low as VND29,000–45,000.

But Vietnamese traders have themselves to blame: Traders in some places advised farmers to dip their fruits in chemicals for cosmetic purposes.

"Traders told us to dip the fruit in something, but we don't know what it is," Thuan, a young farmer who switched from coffee to durian, said.

With respect to cadmium, farmers need better support in terms of technology and regulations.

Durian trees, with their deep roots, can easily accumulate cadmium, especially in acidic, low-humus, clay-rich soils.

The risk increases with overuse of superphosphate fertilizer and industrial chicken manure, both of which can be high in cadmium.

Yet cadmium-contaminated soil is not hopeless. Science shows that cadmium can often be kept in the soil with proper remediation, which involves increasing the organic matter, raising soil pH and using biochar, all of which help reduce plant uptake.

With 150,000 hectares under durian now, farmers urgently need clear regulations and practical guidance.

Key questions include how to quickly detect large-scale cadmium contamination, what support mechanisms exist for remediation if contamination is found and whether authorities will publicly identify fertilizers with high cadmium content.

The answer lies in data and technology.

Rather than waiting for export rejections, researchers that I work with have developed cadmium risk maps by combining soil surveys, remote sensing, topographic data, cropping history, and sensor data.

These tools allow authorities and exporters to focus testing and interventions in the highest-risk areas and help buyers target low-risk regions.

While scientists and officials seek solutions, unsold, rejected durians pile up on roadsides across Vietnam.

So are we consuming fruits another country deemed unsafe? A lack of control at the source not only causes economic losses but also erodes trust and threatens public health.

Vietnam does have food safety standards for cadmium, but no maximum threshold for cadmium in fruits like durian.

The Chinese standard is 0.05 mg per kilogram, consistent with WHO and FAO guidelines.

Without domestic regulations, durians rejected for export are simply sold at home. Should Vietnamese consumers not be equally protected?

To resolve this, Vietnam needs clear standards, effective root-control strategies and cooperation between government, scientists, businesses, and farmers.

Technology can help the industry master these challenges, saving farmers from anxiously waiting for bad news from the border.

If we act collectively for the industry and public health, and help growers improve their soil, cadmium contamination can be resolved quickly.

But in the absence of regulations, importers will impose stricter controls, domestic confidence will erode and the market will become chaotic.

*Nguyen Do Dung is an expert in urban planning and smart agriculture.