The poorly known Ethiopian crop Enset

Enset, a relative of the banana, provides the staple food for around 20 million Ethiopians, yet is barely known outside of the region.

The traditions of the highland farmers of Ethiopia may hold the promise of food security for millions of people in region more often associated with famine. But the potential is unknown as the crop is understudied.

Tall enset plants or else it's a tiny tiny man
Large enset plants (landrace ‘Medasho’) grown by small scale farmers in Teticha (Sidama Zone, SNNPR region). Photo Borrell et al. 2019

A review in Annals of Botany looks into the domestic crop. But if you’re not familiar with the plant, you’re not alone as one of the authors, James Borrell explained. “Enset is an enormous, towering and impressive banana-like plant, but despite its size, no-one has ever heard of it! Anywhere it grows it draws the eye because it’s so odd. All the more remarkable is that it has only been domesticated in one tiny part of its range, and that it now provides the staple food for 20 million people.”

Enset distribution
Three species of Ensete occur in mainland Africa, Ensete homblei, E. livingstonianum and E. ventricosum, with a fourth, E. perrieri, restricted to Madagascar. See Borrell et al. 2019 for more details.

The plant is found in Ethiopian highlands, towards the west of the country. It’s an important crop for understanding food security in the region. Borrell said, “This is one of the most fascinating aspects of enset. As far as we know, the enset growing region was very resilient to food insecurity during recent famines in Ethiopia. We think this could be because of enset’s ability to buffer short term food deficits. Enset has been called ‘the tree against hunger’ because it can be planted or harvested at any time of year, propagated easily and stored for long periods. It’s monocarpic, meaning it flowers at the end of its life (perhaps 7-12 years old, depending on the conditions) – but before then, it can be harvested at any time. The flexibility means it can buffer seasonal food deficits. Other regions of Ethiopia that were much more severely affected by famine use other crops as staples, but there are many other variables of course!”

One of the names for Enset is ‘false banana’, but compared to the common banana, Borrell said that enset is a very different plant. “Whilst they look the same, and enset does indeed produce ‘bananas’, the food products are completely different. The most common enset food product is called kocho, and it’s made from the pulped and fermented pseudostem and corm tissue.”

“Enset can be cooked quite quickly – flattened into ‘bread’ it cooks in a few minutes in a hot pan or steamed over boiling water. It’s the processing of the raw tissue that is time consuming and hard work, with fermentation in a pit that can last up to a year!”

As useful as the crop is, it’s not clear how domesticated enset is related to wild enset, including whether or not domestication is still in progress. Borrell said this was for a couple of reasons. “Firstly, enset is harvested before it flowers, reducing the opportunity for gene flow. Secondly, wild enset has disappeared from much of the domestic enset range (or it may never have been there in the first place). Yet despite this, we do expect some limited gene flow, but the implications are still to be determined!”

One of the factors that comes out in the review is that the spread of enset seems to be surprisingly small. The genus is found across quite a bit of Africa and even as far away as China. So is it a crop with a future? Maybe but there are some hurdles as Borrell explained. “Based on the fact that wild enset is so widespread, we think there is probably significant potential to grow enset elsewhere. However, with domesticated enset being ‘endemic’ to Ethiopia, it would be up to the Ethiopian government to permit sharing of genetic resources.”

“Within Ethiopia, the boundaries of the enset growing region are often remarkably abrupt. We think one of the challenges to the spread of enset agriculture is that a significant amount of indigenous knowledge is needed to cultivate and process it to an edible form.”

Borrell and collaborators have a paper examing the uses of domesticated enset in review at the moment, but he also highlights the need for work on the plant. “I would love to see more investigation into enset pest and pathogens. Although we have some limited research in this area, several issues including Bacterial Wilt (Xanthomonas campestris pv. Musacearum) and root mealybugs are pressing concerns for farmers in Ethiopia.”

Roadmap for the sustainable development and exploitation of the Ethiopian starch crop enset for food security and to support livelihoods.

The review concludes with a list of other research topics needed to understand and grow enset. Climate change, obviously, is a problem. Borrell said: “Ethiopia has already experienced 1.3°C of warming and enset is a highland crop that enjoys a relatively cool climate – at least as cool as you can get at 7° North of the equator. This means that in some areas, it is already stressed and farmers are observing changes.” A crop that already grows in the highlands can only move so far uphill.

Another factor the authors identify is genetic diversity. Borrell said, “Landraces could be lost because of changing climate, emerging diseases, loss of indigenous knowledge and also a shift towards other appealing introduced crops. All of these factors will reduce the potential for future-climate adapted enset genotypes and its associated food security benefits.”

Enset currently feeds around twenty million people. The research by Borrell and colleagues shows it has the potential to provide food security to many millions more.

Further reading

Borrell, J. S., Biswas, M. K., Goodwin, M., Blomme, G., Schwarzacher, T., Heslop-Harrison, J. S. (Pat), … Wilkin, P. (2019). Enset in Ethiopia: a poorly characterized but resilient starch staple. Annals of Botany, 123(5), 747–766. https://doi.org/10.1093/aob/mcy214