Coffee trees that have borne fruit for many years eventually become old and unproductive; yields decline and economic returns drop. In such cases, the above-ground parts of the tree can be rejuvenated by cutting back the trunk before the rainy season—ideally about one month in advance. In the Central Highlands, this is usually done in March or April.
Rejuvenation Cutting
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When a coffee plot no longer produces high yields or is no longer economically viable, carry out rejuvenation pruning to start a second economic cycle.
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Cut the trunks at the beginning of the rainy season.
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Saw each trunk so that a 20–25 cm stump remains above ground. The cut surface should be straight and slightly slanted at about 45°. Thin or prune the shade trees so that about 60–70 % of sunlight reaches the coffee.
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One to two months after cutting, select and keep 4–5 strong shoots evenly distributed on the stump. When shoots reach 20–30 cm in height, thin them again to leave only 2–3 main stems. Remove excess suckers regularly.
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Intercrop with shade plants such as legumes to help protect young shoots.
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Pinch or top the main stems at a height of about 1.6–1.8 m and begin shaping and pruning to form a balanced canopy.
Post-Pruning Care
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At each cut stump, apply 5–10 kg of well-decomposed manure plus 0.3–0.5 kg of superphosphate.
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Spread 500–1,000 kg of agricultural lime per hectare.
Irrigation:
Begin watering once flower buds have reached the “pencil tip” stage. Water every 15–20 days until the early rainy season, applying 500–600 m³ of water per hectare each time. The very first irrigation must be heavier—about 700–800 m³ per hectare.
Note: Insufficient watering can dry branches and even kill plants.
Pruning:
Remove weak, spindly, diseased, or overcrowded branches to keep the canopy open. Cut off old branches that have fruited for many years. Where the branch tips have only 4–5 pairs of leaves, prune back 10–20 cm into the canopy so that vigorous secondary branches can develop. If a plant has gaps in the canopy, nurture additional main stems from vigorous suckers.
Fertilization:
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At replanting preparation: For each planting hole, mix 10–20 kg of organic manure with 0.5 kg of phosphate and cover. At planting, add 25 g urea and 25 g potassium chloride (KCl).
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Annual rate per hectare: For a planting density of 1,100–1,300 trees/ha, split applications as follows:
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March–April: 35 % of total nitrogen (N) and 30 % of total potassium (K).
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June–July: 40 % N and 40 % K.
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August–September: 25 % N and 30 % K.
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Application method:
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Organic manure: Every 2–3 years, dig a circular trench (ring) around the canopy drip line about 30 cm wide and 30 cm deep and apply organic fertilizer mixed with phosphate.
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Chemical fertilizers: Mix urea and potassium, apply in a band around the drip line 5–10 cm deep, and cover the soil immediately after application.
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