Dong Thap proactively manages red spider mites on durian during dry season

Red spider mites - a “tiny enemy” causing major damage

At present, the Mekong Delta, including Dong Thap, is entering the peak of the hot season. These conditions are highly favorable for red spider mites to develop and damage durian trees if orchard growers fail to closely monitor and promptly handle.

According to observations from several durian orchards in Dong Thap, red spider mites often appear on the underside of leaves, particularly young leaves, semi-mature leaves, and young shoots. Although extremely small and difficult to detect with the naked eye, this pest reproduces rapidly and sucks cell sap, causing leaves to lose color, dry out, scorch, and fall prematurely.

Mr. Le Trung Thien, owner of a durian orchard in My Phuc hamlet, My Duc Tay commune, Dong Thap province, said that the hot season is the peak period for red spider mite outbreaks. After just several consecutive days of dry and hot weather, mites can spread densely across the underside of leaves. If not detected early, trees quickly weaken, leaves become discolored, dry, and fall off, directly affecting photosynthesis and the trees’ ability to nourish fruit.

"For durian trees, foliage plays a decisive role in fruit development. If red spider mites cause severe damage, the trees become weakened and more likely to drop young fruit, affecting both yield and fruit quality. Therefore, early prevention not only reduces costs but also helps trees remain more stable during the hot season," Mr. Thien shared.

Similarly, Mr. Le Van Phuc, a long-time durian grower in Hamlet 11, Long Tien commune, Dong Thap province, said that this year, red spider mites appeared earlier than usual. Initially, only a few leaves showed mild yellowing, but within several days the infestation spread rapidly.

According to Mr. Phuc, after receiving guidance from technical staff of Viet Nam Pesticide Joint Stock Company (Vipesco) on appropriate control measures, the mite population declined quickly; young leaves recovered better; and the trees regained vigor. However, to achieve sustainable control effectiveness, handling must be carried out at the right time in combination with regular monitoring, rather than waiting until infestations become severe.

In addition to applying pest control products, many orchard growers in Dong Thap have combined cultivation measures such as maintaining soil moisture during the dry season, pruning branches to improve canopy ventilation, and applying balanced fertilization to strengthen tree resistance. Under prolonged hot and dry conditions, preventing orchards from becoming excessively dry is considered one of the key solutions to limit red spider mite outbreaks.

Integrated management to prevent tree decline

According to Mr. Vo Van Nhieu, Head of the Bac Song Hau area at Vipesco, red spider mites tend to break out strongly under hot and dry conditions, especially during extended heatwaves. On durian trees, the pests concentrate on the underside of leaves, feeding on cell sap and causing leaves to lose color, dry out, and scorch, thereby reducing photosynthetic capacity. When the foliage weakens, trees become less capable of nourishing fruit, making young fruit more prone to dropping and directly affecting both yield and fruit quality.

Vipesco currently offers solutions to support orchard growers in early detection of pests on durian trees, timely treatment application, and appropriate active ingredient rotation. Depending on orchard conditions, technical staff provide specific treatment procedures to control populations of green leafhoppers and red spider mites, protect the foliage, and minimize the risk of re-infestation.

"When mite populations begin to increase, growers should apply early treatment using the combination of Zicon 43SC and Tetrazin 20SC. For green leafhoppers, Centrum 75WG can be combined with Vithoxam 350SC. Orchard growers should spray thoroughly on the underside of leaves, apply the correct dosage and sufficient water volume, and rotate active ingredients to reduce the risk of pesticide resistance," Mr. Nhieu explained.

According to Mr. Tran Thanh Tam, Director of the Dong Thap Sub-Department of Crop Production and Plant Protection, following the merger of Tien Giang and Dong Thap, the province now has around 32,100 hectares of durian cultivation, of which 25,685 hectares are currently fruiting. With such a large cultivation area, pest management, especially for red spider mites and sap-sucking insects, needs to be implemented more proactively.

"Sap-sucking pests such as red spider mites often cause severe damage during the dry season, while many diseases tend to develop strongly during the rainy season. Therefore, during the stages when farmers stimulate new shoots and induce flowering for the next crop, regular orchard inspections are extremely important," Mr. Tam recommended.

The Dong Thap Sub-Department of Crop Production and Plant Protection recommends that orchard growers adopt integrated red spider mite management practices, including regular orchard monitoring, early detection when pest populations remain low, maintaining appropriate moisture levels during the hot season, pruning branches to improve canopy ventilation, and ensuring healthy tree care to enhance plant resistance.

When pesticides are needed, farmers should select appropriate specialized pesticides, apply them at the right timing and dosage, use sufficient water volume, and rotate active ingredient groups to minimize the risk of resistance. In the coming period, the plant protection sector of Dong Thap will continue strengthening communication activities, technical training programs, and demonstration models to help orchard growers improve pest management effectiveness.

"Red spider mites may be tiny pests, but they can cause major damage if not controlled promptly. Proactive early detection, combined with proper cultivation practices and technically correct treatment measures, is a key solution to help orchard growers protect yields and fruit quality while ensuring sustainable durian development under increasingly unpredictable weather conditions," emphasized Mr. Tran Thanh Tam, Director of the Dong Thap Sub-Department of Crop Production and Plant Protection.