A Good Mix of Durian Varieties or Cultivars
Growing durian trees from seeds is obsolete.
Durian farmers can now choose to grow and manage specific durian varieties or cultivars based on their own needs and goals.
1st Rule: never plant a single durian variety or cultivar.
The most important rule to remember is that never plant a single durian variety or cultivar in an orchard. Since all plants in a variety have the same genetic make-up, a new disease or disorder that breaks down the genetic defenses will affect the entire variety. This will wipe out your durian orchard and all your efforts will be wasted. To minimize this risk, the best approach to establish a durian orchard is to plant a good mix of durian varieties or cultivars.
2nd Rule: planting several varieties together also help in cross-pollination and fruit set.Planting a few varieties together also helps in cross-pollination and fruit set, thus increasing fruit yield and quality. Remember, almost all durian varieties are self-incompatible or self-infertile and need cross-pollination from another durian variety.
3rd Rule: planting several varieties stretch the durian fruit season over several weeks.
Another advantage is that varieties with different maturity indices can stretch the durian fruit season over several weeks.
Let's take clone D197 or Musang King for an example.
D197 or Musang King
Presently, it is the most popular clone in Malaysia and Singapore. D197 fruits fetch the highest price in the market and is in high demand. There are lots of information on the D197 fruit such as shape, colour, taste, size etc.
But, information on the D197 tree characteristics such as tree vigour, productivity, disease tolerance, etc. is generally lacking. Did you know that D197 is very susceptible to Leaf Spot disease caused by Rhizoctonia solani?
Hot and high humidity favors high incidence of leaf spot disease
Though Leaf Spot or Rhizoctonia disease is relatively easy to control with the proper management practices, there are a host of diseases such as Phytophthora and many others to be wary of.
Therefore, it is very risky to plant only D197 in an orchard unless you have total information on that particular variety or cultivar. The local growing conditions, such as climate and soils, as well as management practices can greatly influence the tree characteristics and its performance. D197 may do very well in a certain area but can be a total failure in others.
D197 is NOT in the list of durian varieties recommended for commercial planting by the Department of Agriculture.
The best approach is to gather as much information as you can, not on just one variety or cultivar but also on other clones or cultivars as well, and talk to as many local people as you can. You can get information from the local agricultural officers, other durian growers in your area, the nurserymen, fertilizers and agricultural chemical suppliers, farm tools suppliers, the fruit buyers etc. Do not forget your immediate farm neighbours for they may have lots of good and/or bad experiences with durian planting.
In Malaysia, the Department of Agriculture recommended 3 varieties for commercial planting in specific agroclimatic zones. They are D24, D99 (Gob kecil) and D123 (Chanee).
Another 4 clones; D145 (Beserah), D158 (Gan Yau), D159 (Monthong), and D169 (Tok Litok) have interim recommendations for very specific areas.
MARDI has 3 durian hybrids - D188 (MDUR78), D189 (MDUR79) and D190 (MDUR88) which are high yielding and of good quality and be considered as good commercial clones.
Recommended durian clones of Malaysia
In Penang, popular clones planted are D163 (Hor Lor), D164 (Ang Bak), and D175 (Ang Hea).
In Selangor, D160 (Buluh Bawah), D162 (Tawa) and Penu (MDUR 505).
In Johore, D168 (Mas Hajah Hasnah).
This recommendation had undergone extensive testing by MARDI.
Like many durian clones, D24 is self-incompatible, and when planted as the only clone in an orchard, will produce low yields and uneven fruit shape. D24 requires cross-pollination from other durian clones for better fruit set.
Research shows that when D24 is planted in a clonal mix with clones such as D99 (Gob kecil), D98 and D114, the performance of D24 increases significantly in terms of yield and fruit quality. D24 has the best fruit quality, follow closely by D99 while D98 and D114 have acceptable quality.
D99 (Kop Kecil)
Another advantage of this clonal mix is that D99 can bear fruits during the off-season and thus is able to produce two crops a year. It is also an early-season clone with fruits ripening in 90-100 days from anthesis. D24 is classified as mid-season clone. Fruits drop from the tree 105-115 days after anthesis.
D98 and D114 are late-season clones with maturity index 120-130 days. This stretches the durian season to more than 3 weeks. Market prices are not affected as early and late-season fruits usually fetch higher prices because of the low production. Even though D24 matures during the peak in the durian fruit season where fruits are plentiful, it always fetches a good price because of its high quality.
Besides D24, three new hybid clones D188 (MDUR78), D189 (MDUR79) and D190 (MDUR88) have been recommended for clonal mix planting. They are all high-yielding mid-season clones with good quality fruits almost at par to D24.
MDUR hybrid durian clones
Thailand uses a similar strategy where 4 major clones are planted according to maturity index;
Artificial cross-pollination using Gra-doom-tawng as a pollinizer is strongly recommended for commercial durian cultivation in Thailand.
|Durian Gra-doom-tawng (Photo Credit DITP)|
Research has shown that when Gra-doom-tawng was used as pollen parent, fruit set percentage was significantly high in Monthong (27.2%), which is a leading cultivar in Thailand. High fruit set was also achieved in Chanee (16.3%) by Gra-doom-tawng pollen.
|Durian Monthong (Photo Credit DITP)|
|Durian Chanee (Photo Credit DITP)|
|Durian Kanyao (Photo Credit DITP)|
In summary, the use of recommended durian clones or cultivars can help you intensify your orchard management to get higher yields, fewer unproductive years, more trees per hectare, higher maximum yield per hectare, much higher mean yield over the orchard's lifespan, more efficient management and lower cost of production.
However, some disadvantages are that the mother tree from where the cuttings or grafted materials are obtained may harbour diseases and pests that are then transferred to the new plants. Ensure planting materials are free from diseases and pests.
A cloned tree generally has a weaker root system than a seedling tree and therefore requires intensive management in keeping with its intensity of cropping.
Clonal trees are expensive and more plants are required for planting.