Amidst a surge in exports, Vietnamese durian producers are forced to tighten technical standards to avoid the risk of having their produce returned.

Durian is becoming one of Viet Nam's key agricultural export products, and import markets are increasingly demanding stricter requirements regarding quality, food safety, and traceability. In reality, even a small mistake during cultivation can lead to the rejection of an entire shipment, risking the loss of planting area codes, packaging facility codes, and severely damaging the industry's reputation.

According to Dr. Tran Thi My Hanh, Head of the Plant Protection Department - Southern Fruit Research Institute, in the context of rapidly increasing durian cultivation area and continuously raising technical barriers in the export market, quality control cannot be done in a fragmented and isolated manner, but must be implemented synchronously and consistently from the orchard to the harvesting, processing, and export stages.

"Just one step being lax can lead to a high risk of shipments being returned or subjected to 100% inspection, directly impacting the competitiveness of Vietnamese durian," Ms. Hanh emphasized.

One of the main reasons why many durian shipments have been flagged recently is the presence of plant quarantine pests, especially mealybugs and fruit flies. These pests not only reduce fruit quality but are also on the list of strict quarantine measures imposed by importing markets, particularly China.

According to Dr. Tran Thi My Hanh, from 2024 to the present, many batches of durian from Viet Nam have been found to be infested with mealybugs such as Pseudococcus jackbeardsleyi, Planococcus minor, Dysmicoccus neobrevipes, or fruit flies such as Bactrocera correcta. Notably, most of these cases stem from inadequate pest monitoring in orchards and incomplete record-keeping as required by the international ISPM 6 standard.

To address this problem, experts recommend increased and regular pest monitoring, along with the application of integrated pest management (IPM) measures. This includes using food traps, sticky traps, and pheromone traps to monitor fruit flies at the correct density; managing ants to limit the spread of mealybugs; pruning appropriately; and controlling tree height to 5-6 meters to prevent overlapping canopies, thereby reducing pest habitats.

In addition, it is necessary to create favorable conditions for natural enemies such as ladybugs, lacewings, and parasitic wasps to thrive; prioritize the use of biological preparations such as Paecilomyces fungi and Metarhizium combined with vegetable oils to manage mealybugs sustainably and reduce reliance on chemical pesticides.

Beyond plant quarantine, importing markets are now particularly concerned about pesticide residues and heavy metals, especially cadmium (Cd). This is a new issue that could directly impact durian exports in the future.

According to Dr. Tran Thi My Hanh, many cases of pesticide residue exceeding permissible limits stem from failure to adhere to pre-harvest withdrawal periods, using pesticides on the wrong crops, spraying at high concentrations, or spraying too frequently. To minimize risks, it is necessary to prioritize biological pesticides, use the correct dosage, apply them at the time when pests are most susceptible, and strictly adhere to the withdrawal period.

Regarding cadmium, durian trees are capable of absorbing and accumulating Cd if the soil, irrigation water, or fertilizers are contaminated. Meanwhile, many major markets such as China, the EU, Japan, and South Korea are tightening cadmium limits in fruit. The Chinese market, in particular, requires that the cadmium content in durian be below 0.05 mg/kg, and all shipments must be tested at a laboratory recognized by both sides.

If cadmium levels are not properly controlled, the consequences will not only be product returns but also the risk of losing the growing area code, a decline in the reputation of the durian growing region, and difficulty in recovering in the short term. Therefore, regular testing of soil, water, leaves, and fruit, and mapping of cadmium-risk areas for management purposes are urgent requirements.

Regarding technical solutions, experts recommend applying lime to raise the soil pH to around 6.0 to reduce cadmium absorption, using balanced NPK fertilizers, increasing the use of decomposed organic fertilizers, and biochar to adsorb heavy metals in the soil. Additionally, intercropping with plants capable of absorbing cadmium, such as mustard greens, mint, or water spinach, or planting vetiver grass at garden boundaries and ditch edges, can help limit cadmium migration into the durian root zone.

Based on research and demonstration models, Dr. Tran Thi My Hanh affirmed that sustainable durian production is not only a technical requirement but has become a vital condition for the industry to maintain and expand its export market. Controlling pests, pesticide residues, and heavy metals needs to be implemented right from the orchards with the coordinated involvement of farmers, cooperatives, businesses, and specialized agencies.

Source: Agriculture and Environment News