Robusta Trees with Many Branches but Few Fruits: A Lesson from Canopy Management and Pruning

Looking at a healthy coffee plantation, with a dense canopy and numerous branches, it's easy to think that the trees are thriving. However, the number of branches visible on the trunk does not necessarily mean that they are all contributing to the yield.

A study at the Bangelan coffee plantation in East Java, Indonesia, observed a notable case: the 1957 planting group had an average of 49.8 fruit-bearing branches per tree, but the coffee yield was only around 1.1 kg per tree. The researchers attributed this to the dense and deep branching, as well as the strong development of suckers, which hindered the effectiveness of the branch system.

This is a significant issue in long-term Robusta management: it's essential to retain the framework of fruit-bearing branches rather than trying to maintain as many branches as possible on the tree.

When the number of branches no longer reflects the yield

A 2025 study published in Buletin Agrohorti surveyed five areas at the Bangelan plantation, corresponding to plantings in 1935, 1957, 1967, 2007, and 2012. Each group of planting years was observed on 10 trees during the January-April 2020 period.

The results of the two groups showed that the number of branches needs to be read in conjunction with the growth status and actual yield:

• The 1957 planting group had an average of 49.8 fruit-bearing branches but only around 1.1 kg of coffee per tree.
• The 1967 planting group had an average height of 212.3 cm after pruning and 84.5 fruit-bearing branches; the B0 ratio, i.e., branches without fruit at the time of evaluation, accounted for 56%.

The researchers noted the phenomenon of excessive branching, deep damage, and strong sucker development in the low-yielding group. The authors also pointed out that the implementation of wiwil kasar and wiwil halus operations did not meet the required cycle and care area, which may have led to an unbalanced branch system.

It's worth noting that this study is not a controlled experiment to prove a single cause. This is a field survey of trees with different ages and management histories. The numbers should be viewed as case studies, not a standard branch threshold applicable to all Robusta plantations.

Another study in Malang, published in 2024, surveyed Robusta plantations with the same 2013 planting year at three locations. The authors noted that the thinning method had a positive impact on the number of fruit-bearing branches and yield. The report recorded a 73% increase in yield under the study conditions.

This increase should not be understood as a 73% increase in yield for all Robusta plantations simply by pruning. The conditions of the plantation, tree status, pruning method, nutrition, and care history can all lead to different results.

Distinguishing Fruit-Bearing Branches and Suckers

Coffee trees have two important types of branch growth in canopy management:

• Orthotropic (straight): grows vertically, creating the tree's framework and new growth axes.
• Plagiotropic (horizontal): grows horizontally, creating fruiting positions on the tree.

Suckers are not always harmful. Some suckers need to be retained to replace the main stem or recreate the tree's framework when necessary. The problem begins when suckers develop excessively, competing for space and making the canopy dense, while fruiting branches are not well maintained.

In reality, the plantation manager needs to observe all three factors: the number of living branches, the percentage of branches that are actually fruiting, and the degree to which suckers occupy space in the canopy. A tree with many branches but most of them are weak, unfruiting, or shaded cannot be evaluated like a tree with well-distributed branches.

Before pruning, it's essential to read the status of each tree

Instead of applying a fixed number of branches to the entire plantation, a table for observation can be used to determine the areas that need intervention:

It's crucial not to mechanically remove all suckers. A healthy shoot can become a useful replacement when a tree needs to replace its stem or regenerate its framework. Conversely, retaining too many unplanned suckers will make canopy management more challenging

Measure pruning efficiency using data from the orchard

To determine if a pruning method is truly effective, monitor the same group of trees before and after intervention:

1. Record the number of fruiting branches, suckers, and disease status before pruning
2. Mark the trees or rows that have been pruned
3. Record the remaining branches, regrowth status, and canopy openness after pruning
4. Monitor the fruit yield per tree and processed kernel yield
5. Compare with the area that has not changed its care method under the same seasonal conditions if possible

The key indicator is not the number of branches cut, but the tree's yield and growth after adjusting the branch system. If pruning causes the tree to lose too many fruiting positions, the cost of lost yield may outweigh the benefits of a well-aerated canopy

For old or complex canopy structures, test on a small area before applying it widely. Planting year, variety, density, pruning history, and soil conditions all need to be considered

Two studies in Java found that having many branches does not automatically result in high yields. The canopy needs to be managed according to the function of each branch, fruiting ability, and tree renewal rhythm

For further information on coffee plants and production techniques, please refer to the SAVINA Coffee Library at https://caphesachvietnam.com/.

References

• Febrianto, H. N., Supijatno & Djoefrie, M. H. B. (2025). Robusta Coffee Pruning Management in Bangelan Estate, East Java. Buletin Agrohorti, 13(3), 401–410. https://doi.org/10.29244/agrob.13.3.67704.
• Atikah, N., Suhartanto, M. R. & Wachjar, A. (2024). Pruning Increases Productivity of Robusta Coffee in Malang, East Java. Buletin Agrohorti, 12(2), 294–303. https://doi.org/10.29244/agrob.v12i2.51583