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The garden isn’t always greener on the other side of the fence

September 8, 2016

Almost everywhere on Nigeria’s rural lands, colourful, varied, and nourishing vegetables grow in abundance. This is the case with worowo, a green plant with large bitter leaves that are delicious once cooked; amaranth, recognizable from the cluster of red grains emerging from between its leaves; or the fluted pumpkin, a large green gourd with pale flesh.  

However, Nigeria’s indigenous vegetables—those that grow naturally in Nigeria—are not popular fare in the countryside, and even less so in urban areas, explains Osun State University agronomics professor Odunayo Clement Adebooye. Urban populations consider them to be unrefined. “Their perception,” he explains, “is that these vegetables, because they grow in the bush and are picked wild, are food for the poor.”

So what do urban gourmets prefer? “Exotic” vegetables that are imported into Nigerian agriculture. But these options, such as cabbage, lettuce, and cucumber, are far less rich in nutrients and more difficult to grow than wild plants.

Therefore, Adebooye’s team undertook a mission to make native Nigerian vegetables popular with growers and consumers. “We faced three problems. The first one was marketing, because people were unaware of the nutritional benefits of these vegetables. There was also a usage problem, because people did not know how to prepare them. Lastly, there was an agronomic problem, because farmers did not know how to grow them profitably.”

However, farmers showed little interest in these out-of-favour vegetables. “They said, ‘You, the scientists, want us to grow something that we are not familiar with, but who will buy them?’” said Adebooye. Recognizing the farmers’ reluctance, the researchers selected the vegetables most likely to gain popularity. They based their rationale on the ease of growing the vegetables and on the public’s perception. They conducted tests on a list of 22 vegetables to identify those that best met their criteria. Three of them stood out: amaranth, fluted pumpkin, and scarlet aubergine.

To convince growers to cultivate these plants, Adebooye’s team had to prove that people would buy them. The researchers launched a radio, television, and print promotional campaign, covering all of southeastern Nigeria, featuring a character named Ramo the vegetable seller. “The first advertisement was about production; we explained how the vegetables could be grown. The second was about use; we told people how to cook them. The third was about distribution; we told people about places where they could buy them,” said Adebooye. Ten million listeners tuned in daily, he added. In all of the advertisements, the researchers provided a telephone number where they could be reached for more information.

Once the Ramo promotions sowed the idea that indigenous vegetables were a good option, the researchers at Osun State University recruited farmers to train in plant cultivation. A total of 22 cooperatives consisting of more than 1200 farmers, half of them female, participated in the project. “It wasn’t easy to recruit them,” said the agronomist, explaining that farmers were hesitant to dive into growing new varieties of vegetables. The farmers were supported throughout the project, learning how to sow the seeds, protect the plants from pests, and maximize their crops. Their status as a cooperative made obtaining loans to modernize their equipment easier.

The researchers also committed to involving women in the process. Women play a major role in growing and selling vegetables in Nigeria, but they rarely have the authority to make decisions, explained Adebooye. “We gave women leadership roles in the cooperatives.”

Although the project participants were already seasoned farmers, the researchers used the opportunity to fine-tune their work techniques. The team at Osun State University worked with researchers at Université de Parakou in Benin. There, Professor Pierre Irenikatche Akponikpe’s team introduced a technique called microdosage, which maximizes crops using minimal amounts of fertilizer.

The technique consists of applying a light dose of fertilizer directly to the root of the plant. “The farmers generally apply fertilizer on the fly, with doses much higher than the microdose,” explained Akponikpe. “Targeting is poor and there are many losses; the fertilizer doesn’t reach the roots.” He adds that in the traditional method, a farmer digs a hole and sows the seed, followed by a second farmer who spreads fertilizer in the field. “With the microdosage technique, the sower can apply the fertilizer immediately,” he says. Akponikpe estimates that the harvest can be increased by a factor of one and a half by using one-third of the fertilizer required in the traditional method.

The efforts of the researchers from Benin resulted in good crops, and the regularly broadcast messages in Nigeria from Ramo the vegetable seller were a success. “Our advertisements lured people into considering these vegetables, and when they noticed that they got value for their money, demand increased,” explained Adebooye.

The researchers also organized cooking workshops in several Nigerian cities to demonstrate how to prepare the vegetables. “We cooked in front of people and they could eat at no cost. Sometimes 600 people attended,” said Adebooye.

The efforts of Adebooye and his team have put green plants, long snubbed by part of the Nigerian population, in a key place on many tables in the country. Amaranth, fluted pumpkin squash, and scarlet aubergine can be incorporated into traditional Nigerian recipes, but the researchers wanted to go even further to get the most out of these foods, which are rich in nutrients such as polyphenols, as well as packing antioxidant properties. “For example, one problem in our part of the world is anemia, which is often due to an iron deficiency,” said Adebooye. “Yet fluted pumpkin and aubergine have large quantities of iron.”

Adebooye’s team also relied on the expertise of Rotimi Aluko, a researcher in the Department of Human Nutritional Sciences at the University of Manitoba. “You have to eat a lot of salad to get enough nutrients,” laughed the specialist. In his Winnipeg laboratory, Aluko is studying how to extract nutrients from select plants and incorporate concentrated doses in other foods such as orange juice, granola bars, and bread.

In the technique that he perfected, the human nutrition specialist pulverized dried plant leaves to a powder and mixed them with water. He then ran the solution through a centrifuge to isolate the polyphenols contained in the leaves. “We are currently working to optimize the extraction by varying the water temperature, the leaf-water ratio, and the duration of the extraction,” he said.

However, when the polyphenol mixture is ready to be used in making other food, it can impart a greenish hue to the product. “People are averse to eating green bread,” admits Aluko. “But they have to be educated, told that just because it’s green that doesn’t mean it’s bad; it’s even good for them.”

The research project described in this article was made possible with the support of IDRC.

The original French version of this article was published in the June-July 2016 issue of Québec Science.