The rainy season marks the time when Robusta coffee cherries start to expand rapidly, while branches and shoots also grow vigorously. It is therefore essential to provide sufficient nutrients and regulate sunlight to match the plant’s physiological stage so that the tree can both nourish the developing fruit and form a healthy framework of reserve branches for the following year.
Key Care Practices for Coffee During the Rainy Season
Table of Contents
1. Timely Pruning of Shade Trees
In young coffee plantations (in the establishment stage), prune temporary shade trees such as Cassia siamea planted between coffee rows. Cut them back to a height of 50–70 cm to stimulate regrowth. During the rainy season, prune these trees 2–3 times so that coffee does not compete for light. Use pruned branches and leaves as mulch around the coffee base.
In mature plantations with permanent shade trees like Leucaena or Albizia, prune at the beginning of the rainy season to increase light, ensuring new coffee shoots grow strong and healthy. At the start of the rains, prune heavily, leaving only 1–2 small sap-sucking branches on the shade trees. Place pruned branches on the coffee rows temporarily for their leaves to drop and form green manure before clearing larger branches out of the field. Perform 2–3 prunings per rainy season, with the last one about a month before the rains end.
2. Removing Excess Shoots
Shoots grow very quickly in the rainy season and should be removed about once a month. Also pinch off thin or weak twigs growing in clusters at a single node. At each node, leave no more than three reserve shoots. Thin out secondary branches growing densely at the canopy top to let light penetrate.
3. Green Manuring Trenches
Create green-manuring trenches from about 20 days after the first chemical fertilizer application until 1.5–2 months before the end of the rainy season. Dig trenches 30 cm deep, 1 m long, and 20–25 cm wide along the inner edge of the coffee basin, one or two per tree. Fill with weeds, litter and any available manure before covering with soil. Alternatively, plough furrows 50 cm deep between rows, alternating rows each year to reduce root damage. These furrows also serve as sites for green manure and organic matter.
4. Weeding and Fertilizing
Keep coffee rows weed-free to avoid competition. Apply fertilizer only when the soil is moist.
-
Organic fertilizer: Every 2–3 years, apply 20–30 m³/ha of farmyard manure or 1–2 t/ha of bio-organic compost, combined with green-manuring trenches.
-
Lime: Apply 300–400 kg/ha/year of powdered lime evenly on the soil surface.
-
Chemical fertilizer:
-
Young coffee (years 1–3): Use NPK 16-16-8 or 20-20-15:
-
Year 1: 400–600 kg/ha
-
Year 2: 600–700 kg/ha
-
Year 3: 800–900 kg/ha
Divide into 3 applications during the rainy season.
-
-
Bearing coffee: Use balanced NPK formulations suited to rainy-season needs. For yields of 3–4 t/ha, apply:
-
Early rains: 500–700 kg/ha
-
Mid rains: 700–800 kg/ha
-
Late rains: 800–1,000 kg/ha (at least 20 days before rains end).
If yields exceed 4 t/ha, increase each dose by 150–200 kg/ha. Dig shallow trenches around the canopy edge, spread fertilizer evenly, and cover with soil.
-
-
5. Shaping and Branch Management
For young productive trees, once the canopy is stable, develop a second tier at the start of the rains by allowing one shoot to grow about 10 cm above the first topping point. When the tree reaches 1.6 m, top again and maintain that height. Remove any vigorous new shoots at the canopy top.
For older coffee fields, after harvest remove old, weak, diseased or unproductive branches. At the beginning of the rains, carry out a light pruning to eliminate any newly formed dry or useless branches. Around August–September, when cherries are large, prune again to set a framework of healthy, short-internode branches for next season’s flowering.
6. Pest and Disease Management
-
Green scale (Coccus viridis) and Brown scale (Saissetia hemisphaerica): They attack young shoots, branches, leaves and developing fruit, sucking sap and causing defoliation and fruit drop.
Control: Keep plots weed-free, remove low branches that allow ants to spread scales. Spray Bi58, Subatox, Suprathion, Supracide or Pyrinex at 0.2–0.3% concentration, two applications 7–10 days apart, only on infested trees. -
Coffee Berry Borer (Stephanoderes hampei): Attacks maturing and ripe cherries and can develop in dry cherries left on trees, on the ground or in storage.
Control: Collect all ripe and dry cherries promptly and maintain storage beans at moisture below 13%. -
Coffee Leaf Rust (Hemileia vastatrix): Appears early in the rains and peaks late rainy season, causing orange spores on leaf undersides and defoliation.
Control: Spray Tilt, Bumper, Bayleton at 0.1% or Anvil at 0.2%. Spray thoroughly on the leaf undersides. First spray when about 10% of leaves show infection (2–3 months into the rains), repeat 2–3 times at one-month intervals. Remove heavily infected trees and graft with rust-resistant Robusta clones. -
Anthracnose of branches and fruit (Colletotrichum coffeanum): Causes brown lesions on branches and fruits leading to dieback and fruit drop.
Control: Maintain balanced fertilization and proper shading, prune affected branches. Spray Carbendazim 0.2%, Tilt 0.1% or Bumper 0.1% two to three times, 15 days apart. -
Pink disease (Corticium salmonicolor): Appears late in the rainy season on upper branches near branch junctions and tips, starting as white spots that turn pink and can girdle branches.
Control: Detect early and prune infected branches. If widespread, spray Validacin 2% or Anvil 0.2% two to three times, 15 days apart.
Summary
During the rainy season, proper pruning, balanced fertilization, timely pest and disease control, and careful canopy management help coffee trees both support the current crop and build strong reserves for next year’s harvest, ensuring sustainable high yields.