Watering durian during business period

Durian business needs stable water but is very afraid of waterlogging and water shock. Instructions on irrigation according to recovery stages, flowering, pistil flushing, fruit setting, fruit rearing and pre-harvest treatment for orchards in the West and Southeast.

Summary: Irrigation of commercial durian is difficult in that each stage requires a different water signal. Before flowering treatment, it needs to be moderately dry; When the flower buds are clear, they need to be watered again; When removing pistils, do not shock with water; When growing fruit, it needs to be evenly moist; Before harvesting, avoid excessive watering. This article guides you on reading soil moisture and watering according to the plant's physiological cycle, not on a fixed schedule all year round.

Applies to: Durian Ri6, Dona, Monthong in the Southwest, Southeast and low Central Highlands. Business tree from 5 years old or more.
Duration: Year-round water management.
Difficulty level: Advanced. Need to coordinate with flowering and fruit raising treatment.
Estimated additional costs: 10-40 million VND per hectare per year for electricity/fuel, irrigation maintenance and ditch improvement.

Water principle of durian

Durian has roots that are sensitive to waterlogging and salinity. Silky roots need moist, well-aerated soil:

Lack of water causes leaves to wilt, flowers to fall, and young fruits to fall.
Excess water causes roots to rot, pus leaks, and leaves turn yellow.
Wet and dry shock causes the fruit to crack, the rice to fall, and the fruit to fall.
Salt water prevents roots from absorbing water even though the soil is wet.

Therefore, managing durian juice is to keep it moist at the right time and drain the excess water quickly.

Check soil moisture

Check at the edge of the canopy, where the hairy roots are active:

Dig 20-40 centimeters deep.
Grab the soil lightly.
Soil that is clumpy and does not leak water is moderately moist.
Loose soil means it lacks moisture.
Soil is sticky and smells sour because it's too wet.

Don't just look at the face. The surface of the tissue is dry but the bottom is still moist, so you don't need to water it vigorously.

Irrigation in stages

After harvest

Irrigation if the soil is dry.
Do not skip watering completely because plants need water to grow new roots.
Combined with decomposed organic fertilizer, restores foliage.
Avoid waterlogging because after autumn the plants are weak and the roots are susceptible to disease.

Before flowering treatment

Create moderate dryness according to the flowering process.
Do not let the plant wilt or lose its leaves.
Western orchards need rain cover/ditch water control if dealing with off-season.

Moderate dryness is a physiological signal; If it dries out, it will damage the tree.

When the flower buds are clear

Irrigation slowly restores.
Do not water too vigorously after a dry period.
Keep moisture stable so flower buds develop evenly.

Remove the pistil and set young fruit

Keep moderately moist, don't let it dry suddenly.
Do not water or spray flowers.
Avoid excessive rain/humidity, which can cause flower diseases and young fruit to drop.

Raising fruit

This is the stage that needs the most even moisture.
Irrigate according to the weather and soil moisture, avoid strong fluctuations.
After heavy rain, water must be drained immediately.
The last 45-75 days before harvest need to be especially stable to reduce fragility and cracking.

Before harvest

Keep moderately moist, don't let the plant wilt.
Do not irrigate after a drought.
If there is a lot of rain, prioritize drainage and reduce root moisture.

Irrigation method

Drip or drip irrigation

Suitable for business orchards.
Easy to divide water many times, avoid shock.
Need to filter water and check for blockages.
Do not place the watering point close to the root collar.

Irrigation of ditches

Popular in the West but high risk:

Only put water in the ditch to the level needed.
Do not let water rise close to the root neck.
Proactively discharge water during heavy rain.
Check for salinity before taking water into the ditch.

Original cabinet

Root cabinets help retain moisture in the dry season:

Use straw, dry grass, clean leaves, and processed organic bark.
Leave 15-20 centimeters of root collar.
During the long wet rainy season, you need to remove the roots if they are too wet.

Salt water management

Do not water durian with salt water. Before taking water into ditches or lakes:

Measure salinity with an EC meter or suitable device.
Close the drain when salt water rises.
Storage fresh water before the dry season.
If you accidentally water with salt water, stop immediately and wait for a stable source of fresh water to slowly wash away the salt water.

Do not remove salt water by watering too much at once when the roots are weak. Need to do it step by step and have good drainage.

Common mistakes

Irrigate on a fixed schedule all year round: ignore plant physiological stages.

Leaving the ditch submerged for a long time: roots lack oxygen, root rot increases.

Watering vigorously after drying: water shock, flower drop or fruit physiological disorders.

Do not measure salinity: water that looks clear can still be salty.

Keeping the roots close to the root collar in the rainy season: retains too much moisture, increasing root disease.

Monitor and record

[ ] Watering date, watering hours or water amount.
[ ] Soil moisture before irrigation.
[ ] Ditch water level and drainage ability after rain.
[ ] Salinity of water sources in dry season.
[ ] Rate of flower loss, young fruit loss, fruit cracking/sagging.
[ ] Signs of weak roots or leaking pus.

Water data is the foundation to explain many problems: irregular flowering, fruit drop, rice failure, root rot.