Coffee tree management and crop protection

Tree management 

Closer spacing provides higher yields in the first few years of a plantation’s life, but can lead to competition once trees are fully established. Traditionally, Arabica was planted at around 1350 trees/ha – 3 m apart. The more vigorous Robusta was spaced more widely at around 1000 trees/ha.

However, with today’s more intensive production systems, the planting densities are higher, around 4-5 000 plants in shaded plantations and up to 10 000 plants when grown in full sunlight with double rowed plantings. A line of taller tree windbreaks - or intercropping with plantains – is often practiced to minimize wind damage.

While some older plantations were completely shaded, it is now common practice to plant coffee without shading trees and to use fertilizer to fuel the higher yield potential crop. 

Pruning is essential to maintain good coffee production. Fruit is mainly formed on two year-old wood, so pruning to encourage the formation of fresh branches is critical for high berry numbers and maximum coffee yields. 

It is also important to allow light and air movement into the tree canopy to reduce pest and disease problems. Pruning will also aid spray penetration, remove old or diseased wood and ensure easier harvesting of the crop. Arabica, in particular, is prone to biennial bearing, which puts the tree under considerable pressure because coffee is unable to shed fruit. Pruning and a good fertility regime helps regulate production across the seasons.

Irrigation 

There are 3 main irrigation methods: basal irrigation (drenching), Sprinkler and drip irrigation. Basal irrigation is the most popular methods in Vietnam because it is simple and cheap. By using this method, a very certain and uniform amount of water (200-600 liters/tree/round) is provide to the tree. The grower needs only a pump and water pipe in order to irrigate tree by tree. Nowadays, due to lacking of labor in agriculture, some grower invest for sprinkler irrigation, however, this method is sometime leading to uneven or overlap irrigated area within a same field.

Leaf litter management 

In some coffee area with long dry season, keeping leaf litters onto space around coffee stump is very effective to maintain soil moisture hence it allow coffee root developing during dry season. In other areas, growers also keep weeds around coffee stump but this will lead to nutrition competition between coffee and weeds. Therefore, an official recommendation of leaf litter cover during dry season is applicable in Robusta coffee area in Vietnam.

Crop protection 

Coffee is at risk of damage and yield loss from a wide range of pests and diseases. Arabica is particularly susceptible compared to the more vigorous Robusta species. Leaf miners, mealy bugs, scale insects and mites attack leaves, stems and branches. Borers attack stems and also cherries and nematodes damage roots. Diseases that cause significant yield loss include.

Hemileia vastatrix, leaf rust, which leads to premature leaf drop, significantly curtailing the following year’s yields and Cercospora coffeicola, brown eye spot which also attacks berries rendering them unmarketable.

The coffee berry disease, anthracnose causes black, sunken lesions in berries, which eventually rot and drop from the tree.

An important fungal disease in coffee is Mycena Citricolor (Ojo de Gallo). Copper fungicides have been widely used to control these and other diseases, but the use of systemic fungicides is now more common.