The first thing that a durian farmer or grower must do right the first time is when sourcing for durian saplings.
The issue is not about not getting a fair price for the saplings bought but rather to buy the correct clone type saplings that one intends to grow. The mistake that could happen (and it happens quite often) is when a grower buys the wrong clone type saplings only to know it after the tree has bear its first fruit. This will be 5-6 years down the road.
Some of the clones do exhibit specific characteristics mostly in its leaf shape or form or even color (eg: the Musang King or D197 has a wavy form at the edges of its younger leaves) while the Duri Hitam or D200 clone exhibits droopy branches. These characteristics could help the farmer or grower to identify the clone.
The issue nonetheless, is some clones exhibit similar or identical characteristics while some does not even have special characteristics at all.
The safest bet for a farmer or grower in getting the correct clone types is by sourcing saplings from an SPBT certified fruit plant nursery. SPBT or Skim Pengesahan Bahan Tanaman (Planting Material Verification Scheme) issued by the Department of Agriculture.
This SPBT certification scheme does not only apply to durian saplings but to most tropical fruits such as mango, jackfruit, pineapple and mangosteen whereby the Department of Agriculture shall verify the clone/cultivar type and records the origin of the matured trees upon which the scion or young stem/shoot is taken for grafting by the nursery.
These record documents the verification and trace-ability of the scions or other vegetative propagation materials that the nursery sources for its clone seedlings grafting activity.
It has to be said that this scheme is for clone fruit saplings and not heirloom saplings of any fruit.
Farmers and growers could sourced their durian saplings from these certified fruit nurseries which are listed in the Department of Agriculture's website at http://www.doa.gov.my/index.php/pages/view/399. This list will be updated periodically.
As for myself, I sourced my saplings from three certified nurseries in Kajang, Muar and Bidor. I once bought 2 Musang King saplings from Universiti Putra Malaysia (UPM) , formerly the Malaysia Agricultural University. This university managed plant nursery doesn't have an SPBT certification but I do trust them.
I would like to advice that not all nurseries with saplings planted in polybags bearing the Department of Agriculture's logo are SPBT certified. Likewise, a normal polybag without the department's logo does not indicate that particular nursery doesn't have an SPBT certification.
Why buy grafted durian saplings?
In Malaysia and I would believe likewise in other durian producing countries, there are 3 categories of durians. One is the native durians, another is the clone durians. The last category is the wild or jungle durian.
The native durians are also called 'kampung' durians meaning although they are not considered heirlooms but these fruits are produced from matured trees which grew naturally from seed.
The reason I would not call these kampung durians as heirlooms is because their trees grew from seeds which is a result of sexual reproduction between a male gene and a female gene either from the same tree or genes (male or female) from other kampung durian trees.
Kampung durians are inconsistent in taste and other characteristics. They have large seeds with thin flesh and mostly are pale cream or even off-white flesh coloration. Some of it have watery flesh as well.
Because of this, kampung durians have lower commercial value since buying kampung durians is like rolling the dice. It doesn't have a standard quality or fruit expectation and even the sellers don't really know what to expect until he opens the fruit for the buyer to see.
The clone durians come from trees which were grafted. These durians have much more commercial value, better tasting, flesh coloration and overall consistency in terms of flavor.
In Malaysia, clone durians are the ones with registered names starting with the word 'D' followed by a number, eg; D197, D99 or D168. It has to be noted nonetheless, that some clones doesn't have a 'D' name. This is by virtue of it not being registered with the Department of Agriculture.
Clone durians comes from trees that were originally produced from a scion of a known clone and grafted with a rootstock of a native or kampung durian. This is an asexual reproduction hence the word 'çlone' durians.
The reason of having a native/kampung rootstock is that these rootstocks have better root disease resistance, drought tolerant and better adaptability to local soil conditions.
It has to be noted, while native/kampung rootstock are the normal practice but the best rootstock is still the seedling from a jungle durian.
The jungle durians are considered fairly heirloom. Its tree are quite hard to find especially in Peninsular Malaysia although it still exist in deeper areas of the forests. The reason behind this is due to forest clearing to make way for commercial crops or even clone durian plantations.
Jungle durians have an unpleasant taste, some could have nauseating effect if consumed in large amounts. Physical appearance wise, it has longer and winding thorns.