No single Arabica variety is best for all regions: Lessons from a 32-variety trial at 17 countries

One coffee variety can produce very high yields in one region but decrease efficiency when moved to a different climate zone. This does not necessarily mean the variety is of poor quality. It may simply be that the environmental conditions are not suitable for its growth characteristics.

A study published in Scientific Reports on October 2, 2026 analyzed data from the international multi-location trial, evaluating 32 Arabica varieties at 30 trial sites in 17 countries. Rather than simply ranking varieties by average yield, the research team considered the interaction between genotype and environment, and also assessed the severity of coffee leaf rust disease.

The results show that selecting a variety requires answering two questions: which variety has good potential and how does it perform in a specific climate?

What does the multi-location trial address?

In plant breeding research, a variety is usually evaluated at a few trial sites. However, results at one site are not sufficient to predict the variety's performance elsewhere.

Two trial sites can differ in terms of average temperature, daily temperature range, rainfall, humidity, and dry period duration. These factors affect growth, flowering ability, fruit development, and disease pressure.

The International Multilocation Variety Trial (IMLVT) was launched by World Coffee Research in partnership with international partners in 2015. Arabica varieties were taken to different trial sites and evaluated according to a common protocol to better understand the differences in yield and disease resistance between environments.

The key aspect of this design is not just to ask which variety is at the top, but also to see how the ranking of each variety changes as the climate changes.

What is genotype-environment interaction?

In genetics and plant breeding, genotype-environment interaction (Genotype × Environment interaction, abbreviated G×E) describes the phenomenon where different genotypes react differently to changes in the environment.

For example, variety A may produce higher yields than variety B in a cool climate, but at a hot and temperature-stable site, variety B may perform better. When the ranking or the difference between varieties changes with the environment, researchers need to analyze G×E rather than relying on a single average yield figure.

This is why it is not advisable to select a variety solely based on the highest yield reported in a particular location. It is essential to know the conditions under which the variety was tested and its stability across multiple environments.

Which varieties stand out in the study?

Among the 30 trial sites, four varieties with notable average yields were EC16 (Mundo Maya), H1 Centroamericano, Parainema, and Ruiru 11.

However, the varieties do not have the same climate preferences:

• EC16, Parainema, and Ruiru 11: performed better at cooler and more temperature-variable sites.
• H1 Centroamericano: tends to be more suitable for warmer and more stable environments.
• IPR103, Colombia 5, and S4808: were noted for their relatively stable yields and good stability across trial sites.

In the combined assessment of yield and coffee leaf rust disease, the two F1 hybrids, H1 Centroamericano and EC16, followed by the Parainema line, showed outstanding overall performance. It is essential to distinguish this result from the ranking by average yield: a variety that ranks high in yield does not necessarily have the same ranking when both yield and disease are considered.

Coffee leaf rust is not solely dependent on the variety

The study also found that the severity of coffee leaf rust disease is related to the combination of environmental conditions, including high temperatures, high humidity, and shorter dry periods between rainfall events.

This is consistent with the nature of the rust disease caused by the fungus Hemileia vastatrix. The development and spread of the disease are influenced by environmental conditions, leaf canopy status, disease source, and the plant's genetic characteristics.

It is not possible to take a single factor such as average temperature to predict the entire disease risk. Humidity, rainfall, leaf wet time, and the variety's susceptibility must be considered.

The research team observed that hybrid varieties and improved lines with added genetic resources generally performed better than pure Arabica varieties in the combined assessment of yield and rust disease. However, each variety has different levels of adaptability and stability.

What needs to be considered before introducing a variety into production?

International trial results are not a list of recommendations that can be applied universally to every farm. A F1 hybrid variety may have an advantage in terms of yield and resistance, but factors such as propagation, plant cost, material supply, and technical requirements can change the economic effectiveness.

Before widespread variety change, consider:

• Temperature conditions and diurnal temperature range at the planting site.
• Rainfall, humidity, and dry season duration throughout the year.
• History of rust disease and major pests in the local area.
• Yield over multiple crops, not just a favorable crop.
• Bean quality and sensory evaluation results if the goal is high-quality coffee.
• Accessibility of plant material, propagation costs, and suitability with the farming system.

For Vietnam, special caution is needed when interpreting this research. The data surveyed is Arabica, not direct evidence to rank Robusta varieties currently grown in the Central Highlands. Arabica regions in Vietnam also need to be evaluated through local experiments, rather than inferring from a trial in another country.

World Coffee Research is continuing to maintain part of the trial network until 2030. Data from subsequent years may help distinguish between high-yielding varieties in favorable conditions and those that can maintain performance when the environment changes.

References

• Gautron, R. et al. (2026). An international multilocation trial reveals genotype-by-environment interactions in Arabica coffee across climate gradients. Scientific Reports. https://doi.org/10.1038/s41598-026-73765-4.
• World Coffee Research (06/11/2026). Ten years, 17 countries, 32 varieties: what the world’s largest coffee variety trial has taught us about climate resilience.
• World Coffee Research. International Multilocation Variety Trial