SHOULD ROBUSTA COFFEE FARMERS ONLY PLANT COFFEE CUTTINGS?
By Eriki Andrew
Robusta coffee is the backbone of Uganda's agriculture, accounting for over 80% to 85% of the nation's total coffee production and making Uganda Africa's largest Robusta exporter. Though commonly known as Robusta Coffee, the plant is scientifically known as Coffea canephora (especially C. canephora subvar. robusta, syn. Coffea robusta). Uganda is also believed to be the birth place of Robusta coffee.
The Robusta Coffee plant has a shallow root system and grows as a robust tree or shrub to about 10 metres (30 feet) tall. It flowers irregularly, taking about 10–11 months for the berries to ripen, producing oval-shaped beans. The robusta plant has a greater crop yield than that of arabica, contains more caffeine (2.7% compared to arabica's 1.5%), and contains less sugar (3–7% compared to arabica's 6–9%). It is less susceptible to pests and disease.
Robusta coffee (Coffea canephora) requires cross-pollination to reproduce because the plants are self-sterile, a single Robusta plant cannot efficiently fertilize its own flowers. This coffee plant depends on pollination agents like wind, bees, and other insects to carry pollen between different plants and the plants must flower at the same time so pollen can move successfully between different genetic varieties. The Robusta Coffee plant therefore requires mixed planting where a coffee farmer must plant multiple distinct varieties or clones together in the same field to ensure good yields.
Traditionally robusta coffee trees were raised through seed. A robusta seed germinates and grows into a seedling and is later transplanted in a main garden and develops into a robusta coffee tree. Because cross-pollination mixes genes freely, the genes in the seed from a robusta coffee tree can end up being very different from the genes of its mother coffee tree. Cross pollination can lead to a high yielding coffee tree producing seed that germinate and grow into trees that are low yielding. In order to reduce on genetic variations caused by cross pollination and preserve good genes like high yielding genes, crop scientists introduced vegetative propagation in robusta coffee production.
What is vegetative propagation? It is a type of asexual reproduction where new plants grow from parts of a parent plant such as stems, roots, or leaves without using seeds. How It works; only specific mother plants provide the genetic material; the new offspring are genetic clones (exact copies) of the parent and reproduction relies on specialized tissues or vegetative parts(cuttings) instead of flowers or seeds.
This vegetative propagation strategy is what gave birth to the commonly used words “coffee cuttings” in robusta coffee production in Uganda. Coffee cuttings became an alternative to the traditional coffee seedling and the benefits of planting coffee cuttings were instantly seen by coffee farmers and these include Exact Trait Preservation: Cuttings copy the exact traits of the mother plant, including disease resistance, flavor profile, and high yields. Uniform Growth: Fields planted with cuttings grow and mature at the same rate, making farm management and harvesting easier. Faster Maturity: Plants grown from clonal cuttings start bearing fruit sooner—often within 24 to 36 months after planting—compared to seedlings. Targeted Protection: Growers can select cuttings from parent lines proven to resist local threats like Coffee Wilt Disease.
In spite of the tremendous benefits of planting robusta coffee cuttings, we cannot use a one size fits all strategy when it comes to coffee planting material.
First of all, coffee cuttings also have some disadvantages which generally include; They require a higher cost of production, more technical expertise, they have weaker root systems, are less drought tolerant, they affect genetic diversity among others.
However there a critical and specific challenges that coffee farmers are facing today that may require us to look beyond only using coffee cuttings as planting material in robusta coffee production.
One key challenge we have as farmers is difference in climatic conditions, Robusta coffee production is being promoted across the country but different regions/areas have different climatic conditions and even different soil types. Some areas have shorter rain seasons, less rain, longer dry spells, higher temperatures, soil types with a lot of murram among others. Such conditions require making very careful choices when deciding on coffee planting materials to use.
Another critical factor that affects choice of coffee planting materials would be production/farming system used by a farmer. Just like with animals where we have farmers using separate farming systems, some who are free range leave the animals to cater for themselves, others are semi-intensive and we also have farmers that use intensive production/farming systems with lots of inputs. Still in coffee production, some farmers use free range production systems, and leave the coffee trees to cater for themselves, others are semi-intensive and others use very intensive, using lots of inputs. Many small holder coffee farmers operate with very restricted financial resources and therefore do either free range or semi-intensive coffee production and would therefore need coffee planting materials that suit their systems. Some coffee clones/cuttings are either very heavy feeders or are very susceptible to drought and would require very intensive farming systems. We therefore cannot give blanket advice to all coffee farmers to plant coffee cuttings.
Another key challenge is climate change, coffee farmers today are having to deal with longer dry spells, erratic rainfall patterns, high temperatures and the majority of coffee farmers are still very much dependent on nature. We therefore have to revisit our strategy on choice of coffee planting materials taking into account climate change. One key strategy of dealing with climate change is increasing adoption of irrigation but again no every farmer can be able to irrigate their coffee. Which brings the need of having coffee planting material that is specific for non-irrigated conditions.
Finally, it is very important to differentiate between a coffee seedling and an elite coffee seedling, the key difference between these two seedlings is that for a seedling to be classified as an “elite coffee seedling”, the mother plants where the seed was got should be known. And we can not completely eliminate use of coffee seedlings from our farming systems; it would therefore be better to make deliberate efforts to produce high quality elite robusta coffee seedlings for particular groups of coffee farmers. Robusta coffee planting material can not be limited to coffee cuttings, we still have to consider elite robusta seedlings and even further explore robusta coffee grafted seedlings.
ABOUT THE WRITER
Senior Coffee Agronomist / General Manager, Heritage Kanaani Farms.
eriqueandrea@gmail.com
0777-400998/0700-762165