The “Local sage” of Xuan Lap and the billion-dong tree

The land of Xuan Lap Ward, Dong Nai City, where Trinh Cao Khai (66 years old, residing in Phu My Quarter), Director of  Xuan Lap Agriculture, Trade and Services Cooperative, was born, grew up, and has remained attached to throughout his life, is famous for many sweet and high-value crops that generate significant economic returns.

Trinh Cao Khai with his family’s nearly 2-hectare durian orchard in Phu My Quarter, Xuan Lap Ward. Photo: Doan Phu

Developing the economy from crops

During Trinh Cao Khai’s childhood, the fruit trees his parents planted were for family consumption only. It was not until 1980, after he married Tran Thi Ngoc Suong, that they began considering developing the family's economy through agriculture. With all the savings they had after the wedding, the couple transferred ownership of 2.4 hectares of land along a stream to start their livelihood.

Coffee was the first perennial crop chosen by Khai and his wife, alongside crops such as corn, beans, and rice, to generate short-term income while waiting for long-term returns. From the day they bought the land and dug holes to plant coffee trees, Khai and Suong's hopes were tied to long days of enduring sun and rain while waiting for the coffee harvest.

After two initial coffee harvests that brought some profit, the couple was delighted when they achieved a bumper crop in 1987, harvesting 3 tons of coffee beans (at that time, 6 kilograms of coffee beans were worth about one chi, equivalent to 3.75 grams, of gold).

Coffee enabled Khai and his wife to acquire nearly 2 more hectares of land, bringing their coffee-growing area to 4.2 hectares. Later, coffee prices began to plunge, making the crop less attractive to growers. The worst period came from 2001 to 2005, when prices fell to only 2,000-4,000 VND per kilogram of coffee beans.

Although they could not avoid losses from investing in coffee cultivation, Khai and his wife, being naturally astute, gradually converted part of their coffee plantation into fruit orchards growing rambutan, mangosteen, jackfruit, and durian under a diversified farming model. The durian varieties planted by Khai and his wife, as well as many local farmers at the time, had very unusual names, such as Chin Hoa from the Mekong Delta. Some growers did not even know exactly what variety they were planting because the trees were grown from seeds taken from fruits they had bought and found delicious. They were not varieties such as Dona, Ri6, Monthong, or Musang King, which are now considered "billion-dong trees" for farmers in Xuan Lap Ward.

Xuan Lap Ward currently has hundreds of hectares of new durian varieties meeting export standards, including Dona, Ri6, Monthong, and Musang King. The locality is also home to Xuan Lap Agriculture, Trade and Services Cooperative, specializing in durian production, and has been granted a planting area code covering nearly 200 hectares.

Trinh Cao Khai recalled that at the time, durian did not generate as much economic value as it does today. There were no established linkage chains, and consumption mainly depended on local markets and traditional marketplaces. The reasons included unclear origins of the varieties and a lack of cultivation techniques. Trees often died after 8-10 years for unknown reasons, fruits dropped uncontrollably, and the flesh was mushy or dry. The fruit's quality could only be assessed after opening it.

Lessons from the “billion-dong tree”

As he entered his 50s, Trinh Cao Khai, after repeated failures, worked out durian-growing techniques suited to the soil conditions in Xuan Lap Ward. Trinh Cao Khai said candidly that he and many farmers at the time did not have standardized varieties, grew trees from seeds, and "picked up" cultivation experience from one another and from other regions. Failure, therefore, was inevitable.

At that time, farmers dug holes 0.6 meters deep and 0.8 meters wide before planting nursery-grown durian trees. With this method, the holes became waterlogged during the rainy season, and trees that could not tolerate the flooding died. Even the trees that survived eventually died after the holes gradually filled with soil, burying the trunks' bases too deeply and leaving the roots unable to breathe.

Fortunately for Trinh Cao Khai and farmers in Xuan Lap Ward, they practiced diversified farming models in which durian was only one among several fruit and industrial crops. Therefore, even when durian failed, they still had income from other crops.

Farmers in Phu My Quarter, Xuan Lap Ward, use the three-root durian planting technique, similar to that used in many other areas of Dong Nai City.

By 2010, the durian cultivation movement began expanding across many localities in Dong Nai, especially in the Long Khanh - Xuan Loc region. During this period, standardized durian varieties such as Dona, Ri6, Monthong, and Musang King, along with new cultivation and care techniques, became available. As a result, Khai and many farmers in the ward were determined to correct past mistakes.

For seedlings, they selected reputable nurseries and suppliers inside and outside the locality. Cultivation techniques were completely different from the past. On basalt red soil without rocks, trees were planted directly on the surface in rows following the slope to facilitate drainage. In rocky soil, farmers dug deep holes, removed all stones, filled the holes with topsoil to ground level, and planted the trees only then. Farmers now clearly understand that durian trees are extremely sensitive to waterlogged, poorly aerated soil.

Speaking about the “billion-dong tree” durian, many people mention Trinh Cao Khai, Director of  Xuan Lap Agriculture, Trade and Services Cooperative. He not only has deep knowledge of the land and different crops but is also willing to learn and apply new durian varieties, along with organic cultivation and care techniques, as well as scientific and technological applications to maximize economic efficiency.

Vice Chairwoman of the Vietnam Fatherland Front Committee and Chairwoman of the Farmers’ Association of Xuan Lap Ward NGUYEN THI HIEN

Trinh Cao Khai said many growers have become so meticulous that they no longer practice mixed-crop durian farming, choosing instead to plant only one variety for easier care and harvesting. Agricultural extension officers and experienced growers have advised them that intercropping durian with other crops or planting multiple durian varieties in the same orchard can create negative impacts in cultivation and pest control. In particular, water supply during flowering is critical, as both excess and insufficient water can affect yields.

Lessons learned from failure prompted farmer Trinh Cao Khai and many others to boldly change their mindset and farming methods. As a result, not only Phu My Quarter but also many other quarters in Xuan Lap Ward are now planted with new durian varieties that generate annual revenue of billions of VND per hectare.

As an experienced durian grower, Trinh Cao Khai has not only enriched his own knowledge but also shared cultivation and care techniques with farmers throughout the region. Xuan Lap Agriculture, Trade and Services Cooperative, where he serves as director, currently gathers 91 households cultivating the “billion-dong tree” in the locality. Members participate in organic durian farming models for export and have been granted planting area codes to protect the brand and stabilize output during peak harvest seasons.

In particular, cooperative members are eligible for preferential loans, scientific and technical support, and timely updates on market information, as well as strict standards required by export durian buyers.

By Doan Phu - Translated by Diec Quyen, Minho