Pepper replanting technique

Replanting pepper should not be replanted immediately on diseased soil. Instructions for liquidating the old orchard, collecting roots, plowing and drying the soil, rotating crops, analyzing nematodes/fungal diseases and preparing safer replanting holes.

Summary: Replanting pepper is a more difficult problem than planting a new one because the soil already has a history of pepper roots, nematodes, root mealybugs and fungal diseases. If you uproot the old orchard and replant it immediately, the risk of slow/quick death is very high. This article guides the replanting process in the following order: clean liquidation, plowing and drying, crop rotation, soil testing, pit treatment and choosing healthy varieties.

Applies to: Old pepper orchards, low productivity, seriously diseased orchards that need to be liquidated in the Central Highlands and Southeast.
Duration: 1-2 years if the soil has few diseases; 3-5 years if the orchard has ever died quickly, died slowly or had severe root mealybugs.
Difficulty level: Advanced. Need to be disciplined in handling soil, not in a hurry to replant.
Estimated additional costs: 20-60 million VND per hectare before replanting, depending on the level of improvement and crop rotation time.

When to replant

Replant when the orchard shows one or more signs:

For trees over 12-15 years old, productivity clearly decreases.
The turret death/failure rate is over 20-30 percent.
The orchard dies slowly, with nematodes and root mealybugs repeating for many years.
The pillars are degraded and difficult to care for.
The cost of maintaining the orchard is higher than the profit.

Not all old pepper orchards can be replanted immediately. If the soil is still healthy, the tree will only decline due to lack of care, and can be restored in parts first.

Why should we not replant immediately

Old pepper orchard land often exists:

Remaining pepper roots carry fungal diseases.
Nematodes in the root zone.
Root mealybug or bamboo shoot.
Pathogens die quickly, die slowly.
Soil is poor, organic matter is poor, microbiological imbalance is present.

Replanting immediately is like putting a young tree into an old "disease nest". Seedlings are weaker than mature trees, so they die faster.

Step 1 — Liquidate the old orchard

After harvest or when deciding to abandon the orchard:

Remove all pepper vines, roots and large roots.
Collect stems, branches, and roots from the plot.
Burn or destroy disease residue.
Do not chop diseased pepper stems to use as green manure in the orchard.
If using a spinal column, evaluate whether to retain or liquidate depending on the disease level and new design.

Remaining roots are a huge source of disease. During the subsequent plowing process, it is necessary to continue picking up the roots many times.

Step 2 — Plow and dry the land

At the end of the rainy season or in the dry season:

Plow the land twice horizontally and vertically.
Depth 40-45 centimeters if conditions allow.
Dry the soil for 1.5-2 months during the dry season.
Then harrow again to a depth of 20-30 centimeters.
Before harrowing, apply 1-2 tons of lime powder per hectare depending on soil pH.

Plowing helps break up the compacted soil layer, reduces pathogens on root residue, and improves aeration.

Step 3 — Crop rotation and soil improvement

Should be rotated for at least 1-2 years before replanting. For orchards that have died from serious illnesses, the time should be longer.

Suitable crop rotation:

Peanuts, soybeans, green beans.
Corn.
Yellow flower bed.
Chrysanthemum or green manure plant.
Some short-term plants are not in the same disease group as pepper.

Goal of crop rotation:

Cuts the life cycle of nematodes and fungal diseases that damage pepper.
Organic supplements.
Cover the soil, reduce erosion.
Give time for the soil to recover.

Do not plant plants that are strong nematode hosts if the soil is already heavily infested with nematodes.

Step 4 — Test the soil before replanting

Before deciding to replant:

Soil sampling at a depth of 0-50 centimeters.
Check pH, organic, basic nutrients.
Analyze nematode density if the orchard has experienced slow death.
Check for fungal diseases in the soil if possible.

If nematodes/fungal diseases are still high, crop rotation and renovation should continue. Replanting now only increases the risk of losing the seed.

Step 5 — Digging and treating holes

Dig holes at least 1 month before planting:

Pit 50 x 50 x 50 centimeters or larger depending on the land.
Burn the remaining remains in the pit if any.
Mix topsoil with 10-15 kilograms of decomposed manure.
Add Trichoderma to compost.
Add 0.2-0.3 kilograms of fused phosphate per hole.
Add 0.2-0.3 kilograms of lime powder if the soil is acidic.
Fill the hole and incubate for about 2 weeks before planting.

Organic fertilizer must be thoroughly decomposed. The replanted soil is already susceptible to the disease, so do not add unrotted manure to the hole.

Step 6 — Choose seedlings

Seedlings used for replanting must be stronger than the "temporary" level:

The roots grow evenly, without twisting the pot.
Green leaves, not mosaic, not curly.
No mealybugs, nematodes, and collar fungus.
Obvious seed source.
Priority is given to varieties suitable for the region, do not chase strange, unproven varieties.

If the old orchard had a viral disease, absolutely do not take seeds from that orchard.

Care for the first year after replanting

Good shade for young trees.
Irrigate to keep evenly moist, not waterlogged.
Do not fertilize heavily with nitrogen.
Organic fertilizer, microorganisms, Trichoderma periodically.
Check the root collar every month during the rainy season.
Dig to check the roots if the tree grows slowly or has yellow leaves.

The first year, don't set a goal for the tree to grow quickly. The goal is a strong root system and a high survival rate.

Monitor replanting

[ ] Proportion of old pepper roots collected.
[ ] Time to plow and dry the soil.
[ ] Rotation crops are planted and biomass returned to the soil.
[ ] Results of pH, organic, nematodes.
[ ] Percentage of trees surviving 30, 60, 90 days after planting.
[ ] The tree shows signs of yellow leaves and root rot.

Good replanting requires data. If you just follow the feeling, it is very difficult to know which step is making the ground return.

Common mistakes

Pick up old plants and replant them immediately: pathogens in the soil are still high, seedlings die early.

Do not collect roots: diseased roots decompose slowly and retain sources of fungi/nematodes.

Cultural rotation is too short in seriously diseased orchards: not enough to cut off the disease source.

No soil analysis: replant when nematodes or pH remains unfavorable.

Using cheap seeds from unknown sources: replanting is already risky, bad seeds double the risk.

Take notes

Reasons for liquidating the old orchard.
Proportion of diseased trees before liquidation.
Day of plowing, harrowing, and liming.
Rotation crops and rotation time.
Soil analysis results.
Source of seeds for replanting.
First-year survival rate.

The replanting diary helps learn from experience if you have to renovate other plots.

References

*Pepper replanting technique* — Hainong technical document.
*Training materials on good pepper production techniques* — National Agricultural Extension Center.
*Pepper pests and prevention measures* — Vietnam Academy of Agricultural Sciences, National Agricultural Extension Center.