Mariene coffee substation is located in a high potential agro-ecozone whose rainfall pattern favors the months of October through December and a short season covering April to May. The period between May to September is characterized mostly by a long dry spell.

The soils are mainly acidic, low fertility, humic nitisols (Dystro humic nitisols and Acrosols). The soils are also highly erosive. The main crop is mainly focused during the early rainy part of the coffee year. However, constraints such as low fertility associated with high soil acidity, pests incidences and improperly timed pruning should be addressed intensively in order to sustain high coffee yields.

The Mariene substation has mature coffee trees numbering approximately 29,543 trees equivalent to 54.71 acres (based on 540 trees per standard coffee acre). These mainly consists of Ruiru 11, SL 28, SL 34 and K7. Under high management practices, the Substation has the potential of realizing approximately 55 metric tones of clean coffee in a year. If this entire crop is concentrated on the early part of the year the cost of production would be greatly reduced.

This cropping level can be sustained by this early cropping strategy. Timeliness in implementing coffee management practices is a key factor towards achieving the stated production potential at Mariene.

In order to address the Mariene substation coffee production constraints, a technical field visit was made to the station from 6th -8th September 2004 to carry out the following objectives:

•     To assess and advise on proper management of the main coffee pests
•     To assess and advise on coffee nutrition and soil fertility management
•     To assess and advise on proper tree training and canopy management