Durian fruit is a strong smelling, strange looking tropical fruit that has been popular in southeastern Asia for several centuries and is finally beginning to gain international appeal. While there are several different types of durian trees native to the region, only a few species bear edible fruit. Today, many producers work hard to cultivate these species and provide the world with the incredible durian fruit
The best location for durian fruit trees
Durian producers know that beginning and maintaining a successful durian orchard requires land that is located within fifteen degrees – about 1,000 miles – of the equator. Although the trees are more tolerant of cool temperatures than many other types of tropical fruits, they do require a great deal of water, prompting many producers to install irrigation systems in their orchards; this goes a long way towards ensuring a good crop even when the weather is drier than normal. While some producers have routinely produced successful durian fruit crops in areas that only receive 75 inches of rain each year, the most profitable crops are grown in areas that routinely receive more than 125 inches of rainfall annually.
One of the biggest challenges producers encounter is determining how to provide the trees with enough water without generating pools of standing water, something the root systems of the durian tree are especially sensitive to. Producers in Penang, Malaysia believe the key is planting durian trees on hills and valley walls. While the steep terrain makes tending the trees more challenging, they also provide the perfect amount of drainage, which is why the region consistently produces the highest quality durian fruit.
Most producers either buy young durian trees or they start their own seedlings in pots filled with sandy soil. Starting the trees in pots allows the producers to better control soil conditions while also protecting the young saplings from disease and predators. The trees do best when planted in soil that is either sandy clay or a clay loam, that drains well and that has a pH level of 6-7. Durian trees have a very low tolerance for any salt in the soil, which is why you will not find any orchards near the ocean.
Caring for durian fruit trees
The amount of care that goes into the trees depends on a series of variables, including the location of the orchard. For example, producers in Thailand are discouraged from using animal manure on their trees because there is concern that the combination of the organic manure and the high moisture in the soil creates an environment for Phythophera palmivora, a fungus associated with fruit and pod rot, to thrive.
However, because there is no proof that organic animal manure has any impact on Phythophera palmivora, producers in other countries not only use it to fertilize their trees, but also report favorable results. Trees grown in drier climates require more irrigation, and producers growing trees in less than perfect soil have to use soil additions including fertilizers, rock dust, and lime to maintain ideal soil pH and nutrient levels.
Producers like to start planting saplings in November and continue planting the trees until about the middle of January. The trees are planted in holes that are two feet deep and two feet wide. Once the hole is dug, the producer pours approximately 10-20 pounds of their preferred fertilizer into the hole and leave it alone for a few weeks before planting the sapling. Care is taken to leave the young tree's roots intact while transferring it from the pot to the hole. The trees do best when they are planted from twenty to fifty feet apart.
In Brunei, producers are urged to mingle both papaya and banana trees with the durian trees.
Starting durian fruit trees
Producing durian fruit is not for anyone interested in instant gratification. Like most fruit trees, it takes time for the trees to become mature enough to produce high-quality fruit. In the case of durian trees, the first fruit crop is harvested when the tree is 4-6 years old. As the trees continue to age, many producers opt to cut down the most mature trees which are not generating as high a yield as the younger trees.
One of the challenges durian fruit producers face is that it is impossible to guarantee how well a tree grown from seedling will produce. Even though the producers strive to only use seeds taken from the most prolific and durable adult trees, the results are inconsistent.
To improve the quality of their orchards, many producers opt to use grafting to replenish their orchards rather than starting new trees from seedlings.
Types of grafting practices durian fruit producers use include:
• Bud grafting
• Wedge grafting (also referred to as cleft grafting)
• Whip grafting
Not only does grafting provide the producers with more consistent results than growing new trees from seedlings, but grafted trees also bear fruit at a younger age than trees grown from a seed. In Malaysia, producers report that it can take trees grown from seedling up to seven years to bear a decent crop, while trees created via grafting will produce the same size crop after just four years.
Durian fruit seeds are not very hardy. They are only viable for a short time after being removed from the fruit and do not tolerate pro-longed exposure to sunlight. Even when placed in cool, airtight storage, the seeds generally only remain viable for less than a month.
Even though many producers prefer to graft trees, there are still some who try to start trees from seeds. In order to increase the odds of success, the producers try to plant the seed as soon as it is extracted from the fruit. It is placed, sprout end pointing downward, into a pot of soil. The seeds do best when only half of the seed is inserted into the soil. If the process is successful, the seed will sprout after just a few days.
Durian trees require the most care right after they are planted. Producers must provide the trees with some protection from both sunlight and wind for approximately one year. Planting the young trees in an area where they are shaded by older trees is one way to reduce the amount of labor needed to care for the sapling. If an older tree is not available, durian producers frequently use shade cloths.
Pruning is an important aspect of Durian fruit production. When pruning the trees, Durian fruit producers remove weak branches and water shoots. Not only does the pruning increase the tree's yield, but it also helps protect the tree from being damaged by broken/falling limbs and increases the odds of the producer identifying health problems that may have a negative impact, not only on the tree, but also on the overall health of the orchard.
Additional crops in durian fruit orchards
It is not unusual for durian fruit trees to be planted in orchards where banana and papaya trees are grown. The taller durian trees help these species by providing a protective canopy. Most producers have also gotten into the habit of planting a legume cover crop in the same area. The legume cover crop does two things: first, it helps reduce the amount of weeding the producer would have to do if they didn't plant a cover crop, second, the sale of the cover crop increases the producer's end-of-year profit.