The production and productivity of both species are largely dependent on the climate for attain high yields and quality.
Temperature and rainfall are important variables as the onset of the dry season and drops in temperature are key in terms of the plant flowering and, thus, producing beans.
Arabica coffee evolved in the cool shady environment of the Ethiopian highlands, where this region has well-distributed rainfall patterns, ranging from 1400–2000 mm for two thirds of the year, with the last third being the dry season and coinciding with the coldest months. The optimum temperature range is about 15 to 24 °C with a precipitation of 1500 to 2000 mm per year. Arabica coffee can tolerate temperatures as low as 15 °C and up to 25 °C.
Arabica coffee needs more than seven months of rainy weather but a relatively high temperature for an abundant differentiation of flower buds. The deep root system permits reasonably good drought tolerance.
Robusta is slightly hardier, as it evolved in lowland equatorial Africa, but grows well in areas with abundant rainfall of about 2500 mm per year. Robusta’s optimum rainfall is between 2000 and 2500 mm. For robusta the rainfall should be well distributed as the plants are shallow rooted. The optimum temperature range for robusta is 24 to 30 °C, but it is more sensitive to lower temperatures. Climate disturbance have led to fluctuations in yield in almost all the coffee growing countries.
Both coffee species, Arabica and robusta tolerate shade and share quite similar growth requirements with various forest crops and trees, thus predisposing them to be grown in agroforestry ecosystems. Growing coffee under full sun with little or no forest canopy causes the berries to ripen more rapidly and the bushes to produce higher yields; this requires shade clearing and increased fertilizer and pesticide uses.
The possible yield and quality of coffee is determined by weather condition. The extended drought periods, which resulted in the reduction of coffee amount and quality. In other cause of climate change such unreliable precipitation throughout growth stages of the crop, be able to influence the easy to discover the soil water and reduce of the crops production.
Climates suitable for coffee cultivation
