Area for growing robusta coffee
Robusta Coffee is more tolerant of pest infestation and is well adapted to warm and humid equatorial climates. And when handled and processed properly, it can be a product for specialty markets, fetching premium prices on the international market.
Soil and Land Requirements
Robusta Coffee can grow on different soil types. But for best root establishment and high yields, it requires a fertile, well-aerated, free-draining, slightly acidic, deep soil with reasonable humus content and a minimum depth of 1-1.5m in well moist and 3m in drier areas. Robusta does not tolerate waterlogging or ‘wet feet’. The best or ideal soils are volcanic red earth or sandy loams with good structure and texture and rich in organic matter. Avoid heavy clay or poor-draining soils, for good productivity.
Besides, the soil should be just slightly acidic, with a pH range of 5.5 – 6.5, within which it would be well supplied with all the essential major plant nutrients. A pH level below 5.5 will limit crop performance and at this level, adequate liming must be done to correct the pH levels back to a suitable range.
Robusta Coffee production requires an altitude range of 900-1500 meters above sea level. Different altitudes produce different cup profiles. Robusta Coffee grown at higher altitude tends to be more acidic and complex while that grown at lower elevation tends to be more intensely flavored. Uganda is a classic case showing differences in elevation. It produces relatively high altitude Robusta Coffee at an average of 1200m above sea level.
Robusta Coffee requires warmer temperatures ranging from 22° – 28°C (71 – 82°F). It is much more tolerant of hot conditions compared to Arabica Coffee. Temperatures higher than 300C can cause a range of physiological problems, including flower abortion poor fruit setting, development, and premature ripening. At this relatively high temperature, photosynthesis is also reduced. On the other hand, frost damage can occur if temperatures fall around 00C or below.
Rainfall and Humidity
Robusta requires a rainfall range of 1,200 mm to1,800 mm, which is well distributed for 9 months. Both the total amount and the distribution pattern are important. Unless there is regular rainfall, young newly planted coffee seedlings should be irrigated (or hand-watered) at least twice a week to ensure that the seedlings get established. Also, where there is inadequate rainfall during growth, supplementary watering/irrigation to sustain continuous growth, induce uniform flowering and good fruit formation should be carried out. A fairly regular/frequent rainfall pattern throughout the cherry development stage is required. A good soaking of 25 mm every 14 days or approximately 20 liters (1 jerrycan) of water per plant is required to stimulate flowering and sustain fruit formation.
Rainfall triggers the flowering and fruit filling process. Without adequate and sustained rainfall/moisture, flowering may extend over many months
making harvesting uneven, more difficult to achieve
good quality of harvested berries and becomes costly
to the farmer.
Excessive droughts can cause the coffee tree to become dehydrated and thus lead to its defoliation and or increased attacks of pests such as the red spider mite, leaf miner, twig borer and the coffeeberry borer or even death through wilting.
Excessive continuous rainfall can, on the other hand, cause excessive vegetative growth and inhibit the flowering of the coffee tree or destroying it altogether. Thus, locating coffee plantation near a water supply for possible irrigation as well as for processing of cherry is desirable.
Strong winds have an adverse effect on coffee growth because they can cause excessive water evaporation and tree breakage and increase the demand for
irrigation. Therefore in especially windy areas, it is desirable to establish windbreakers along borders of the coffee plantation.