Short answer. No fertiliser can force durian to fruit — flowering is triggered by a dry spell in a healthy tree. Before flowering, feed phosphorus and potassium and cut nitrogen; while fruit develops, potassium matters most. Paclobutrazol, studied for flower induction, is a growth regulator, not a fertiliser.
Growers look for a “durian fruiting fertilizer” when trees will not flower, or flower heavily and then drop their fruit. The honest answer: no fertiliser can force a durian tree to fruit. Fertiliser helps a healthy tree carry the fruit it sets. Flowering itself depends on weather, tree age and tree health.
In aseasonal tropics like Malaysia, durian flowering is triggered by a short dry spell; a study in Johor found flowering followed a period of very low rainfall. Trees also need to be mature enough, and damaged roots limit how well a tree takes up water and nutrients.
Fertiliser’s job is preparation: recover the tree after harvest, build healthy leaves, then shift to a high-phosphorus, high-potassium fertiliser ahead of flowering, as in the Thai Department of Agriculture programme.
Once fruit has set, the priority is potassium, the nutrient durian fruit removes most. The Thai programme used 12-12-17 (2,000 g per tree) and 0-0-50 (1,000 g per tree) during fruit development, then 0-0-50 (1,000 g per tree) before ripening.
| Timing | Nutrient focus | Notes |
|---|---|---|
| Before flowering | P and K (e.g. 9-25-25) | After the post-harvest leaf flush |
| Flowering and fruit set | None in the Thai programme | Manage water; boron only if short |
| Fruit development | High K | Water evenly — drought then heavy rain can crack fruit |
| Before ripening | K | Avoid high nitrogen |
Based on the Thai Department of Agriculture programme for Monthong durian. Set actual rates from your orchard’s soil and leaf analysis.
Potassium matters, but do not overdo it: too much chemical potassium can block calcium uptake and contribute to fruit cracking — see why durian fruit cracks.
We found no formal definition of “flower-forcing fertiliser” in the sources we checked. One substance studied for durian flower induction is paclobutrazol, a plant growth regulator, not a fertiliser. In a Thai study, paclobutrazol at 750–1,500 ppm brought flowering forward by 14–45 days with 29–64% more flowers — but fruit set and fruit development were not affected. Such products must be used according to a registered label and agronomic advice. Agros Empire does not sell growth regulators.
Foliar sprays are used for micronutrients such as boron — an industry source suggests boron sprays from flowering to fruiting where analysis shows a shortage. Treat foliar feeding as an addition to the main programme, not a replacement.
The NEXGROW booklet describes NEXGROW Bio-Organic as supporting flower initiation and development (which affects how many fruit set), husk and flesh development and a strong root system, and as possibly reducing the need for synthetic phosphorus. For trees of 5 years and above the dose is 3 kg per tree, applied after harvest — the recovery stage before the next flowering.
During fruit development a high-potassium fertiliser (for example 12-12-17 or 0-0-50) matters most, because durian fruit removes more potassium than nitrogen. Before flowering, focus on phosphorus and potassium.
No. Flowering is triggered by a short dry spell in a healthy, mature tree. Fertiliser prepares the tree; it does not force flowering.
In a Thai study it brought flowering forward and increased flower numbers, but did not change fruit set or fruit development. It is a growth regulator, not a fertiliser.
Related guides: Durian fertilizer programme by stage · Durian flower to fruit · Durian fruit cracking · Durian programme
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