Fertilizer by crop

Durian

The Silicon Techs durian programme — five stages, tested in our Chanthaburi demonstration orchard in the 2026 season (6-year-old Monthong, 20 trees/rai). Yield was 30% higher than with standard fertilizer alone.

Year-round fertilizer calendar

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1Post-harvest recovery & soil care

2Leaf flushes & food reserves

3Build reserves & induce flowering

4Flowering, fruit set & early sizing

5Pulp filling (2 months before harvest)

✂Harvest

Coloured bars show when to apply at each stage. The current month is highlighted.

Stage-by-stage plan

Jun – Jul

Post-harvest recovery & soil care

Trees are exhausted, soil is acidic and feeder roots are damaged — fix the soil and regrow roots first.

Recommended

Orthosilicic Acid Gold (H4SiO4), PowderMa Ngao brand

Mor Kaset Plus 6-6-6 + OM 10%Sam Ma Ngao brand

Chemical Fertilizer 15-15-15Ma Ngao brand

Rate & method: Broadcast Orthosilicic Acid+ Gold powder 3 kg/tree to correct soil pH → Mor Kaset Plus 6-6-6 at 2 kg/tree → one month later 15-15-15 at 2.5 kg/tree.

Or choose

Orthosilicic Acid + Gold (H4SiO4), GranuleMa Ngao brand

Organic Fertilizer OM 20%, Powder & GranuleSam Ma Ngao brand

Organo-Chemical Fertilizer 10-0-4 + OM 50%Sam Ma Ngao brand

On very acidic soil (pH below 5), use orthosilicic acid powder instead of dolomite to add silicon from the start.

Aug – Sep

Leaf flushes & food reserves

Push 2–3 even leaf flushes that harden quickly and build starch for flowering.

Recommended

Chemical Fertilizer 15-5-20Ask your dealer

Mor Durian (Durian Doctor)Mor brand

Rate & method: 15-5-20 mixed 1:1 with Mor Durian, 3.5 kg/tree in total.

Or choose

Chemical Fertilizer 20-8-20Ma Ngao brand

Chemical Fertilizer 16-8-8Ma Ngao brand

Chemical Fertilizer 15-15-15Ma Ngao brand

If 15-5-20 is unavailable, use 20-8-20 or 16-8-8 at the same mix with Mor Durian.

Oct – Nov

Build reserves & induce flowering

Stop new leaves and load up on phosphorus and potassium for heavy, even flowering.

Recommended

Chemical Fertilizer 8-24-24Ma Ngao brand

Rate & method: 8-24-24 once a month at 1.5 kg/tree (twice), together with water stress for flower induction.

Or choose

Mor Kaset Plus 4-8-8 + OM 10%Sam Ma Ngao brand

Chemical Fertilizer 9-9-9Ma Ngao brand

Avoid high-nitrogen fertilizer now, or the tree will flush leaves instead of flowers.

Dec – Feb

Flowering, fruit set & early sizing

The most sensitive stage — reduce fruit drop, firm the stalks and grow young fruit evenly.

Recommended

Chemical Fertilizer 13-13-21Ma Ngao brand

Mor Durian (Durian Doctor)Mor brand

Rate & method: 13-13-21 mixed 1:1 with Mor Durian, 2.5 kg/tree in total.

Or choose

Chemical Fertilizer 12-12-17Ma Ngao brand

Chemical Fertilizer 15-15-15Ma Ngao brand

Water evenly after flowering — avoid dry–wet swings to cut fruit cracking and drop.

Mar – May

Pulp filling (2 months before harvest)

Fill the segments for firm, well-coloured flesh with fewer hard or watery cores.

Recommended

Chemical Fertilizer 15-5-25Ask your dealer

Mor Durian (Durian Doctor)Mor brand

Rate & method: 15-5-25 mixed 1:1 with Mor Durian, 3 kg/tree in total.

Or choose

Chemical Fertilizer 14-7-35Ma Ngao brand

Chemical Fertilizer 15-10-30Ma Ngao brand

Chemical Fertilizer 10-10-30Ma Ngao brand

If 15-5-25 is unavailable, use 14-7-35 or 15-10-30 instead.

Add every time you fertilize

Mor Durian at 0.25–0.5 kg/tree every time you fertilize, without cutting your usual NPK (use 0.5 kg for large or heavily loaded trees).

Mor Durian (Durian Doctor)Mor brand

Choose the approach that fits your farm

Easy start — keep your formulas

Keep your usual fertilizer, add Mor Durian 0.25–0.5 kg/tree each time and use orthosilicic acid powder instead of dolomite after harvest. Extra cost about 616–1,232 baht/rai for 15–20% more yield.

Mor Durian (Durian Doctor)Mor brand

Orthosilicic Acid Gold (H4SiO4), PowderMa Ngao brand

Recommended

Full programme

Follow all five stages above. In our demonstration orchard it gave 30% more yield and 60% more net profit than standard fertilizer.

Mor Kaset Plus 6-6-6 + OM 10%Sam Ma Ngao brand

Chemical Fertilizer 8-24-24Ma Ngao brand

Chemical Fertilizer 13-13-21Ma Ngao brand

Mor Durian (Durian Doctor)Mor brand

Organic focus for tired soil

For compacted, low-organic soils, use OM 20% organic fertilizer or Mor Kaset Plus 10-0-4 (OM 50%) with Mor Durian, then add NPK by stage.

Organic Fertilizer OM 20%, Powder & GranuleSam Ma Ngao brand

Organo-Chemical Fertilizer 10-0-4 + OM 50%Sam Ma Ngao brand

Mor Durian (Durian Doctor)Mor brand

Good to know

In the south, timings run about 2–3 months later than the east — follow the tree’s stage rather than the calendar.
Apply on moist soil around the canopy edge, then water in.
Avoid high-nitrogen formulas during flower induction and just before harvest.

Rates on this page are general guidance for bearing trees. Adjust for tree age, canopy size, crop load and soil test results. Months are approximate and vary by region.

Source: Silicon Techs durian programme and trial report (2026)

Not sure? Ask a local dealer — our team will visit your farm.

Other crops

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