Food crop varieties endangered as scientists rush to save them

Big loss. A farmer looks on in disbelief after her banana plantation was destroyed by a rainstorm at Lumpewe village in Nakaseke District recently. Many species of the banana face extinction. PHOTO BY DAN WANDERA.

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Longing for the past. A number of crop varieties that were commonplace in different places of Uganda have since disappeared or are on the verge of disappearing. Daily Monitor’s Paul Tajuba inquires into the nostalgia about the past and plans for the future as scientists endeavour to save the past

About 15 years ago, Ms Sarah Namubiru’s family used to grow nylon and kyebadula potato varieties in Luweero District. Now as the district agriculture officer for Luweero, Ms Namubiru cannot trace the ‘sweet’ potato varieties.

“They disappeared. Farmers decided to go with the new high yielding varieties that were introduced,” Ms Namubiru says sorrowfully.

What she considers as a local problem, however, is actually a national one that scientists at the National Crop Resources Research Institute (NCRRI) recently conducted a survey to ascertain the extent of extinction of crop varieties.

The survey focused on two crops; cassava and potatoes.
Dr Barbara Zawedde, a researcher with NCRRI, says the survey, which conducted with the aim of identifying traditional varieties for conservation, produced disappointing results.

The survey showed many varieties had disappeared or on the margins of extinction. The endangered varieties include ebwanatereka, ofumbachai, magana in eastern Uganda, okonyoladak and oroyokiraa in northern Uganda.

The others under severe threat are njule, kwatamumpale, mpologoma, Kabwa, ddukaobusolo in central Uganda, Kyebandira, nyakapimpiri, rutuga in south western Uganda, abiria, ariwara, mabulu, palawu and Gbasumenge in West Nile, and welobediyo, nyalanda, Rugogoma, Karangwa, Agong, Kikofiira in mid-western Uganda.

Sweet potato varieties lost in Uganda, according to the survey, include alugbea in Arua, Kawogo mukadde in Masaka, Kawa in Iganga District, kawogo in Mukono District, Kisakyamaria in Rakai District, Kahungezi in Mpigi , ntamankusimire in Kamuli District.

“It is extremely important that this resource is protected and conserved because most of the traditional crop varieties are believed to have undergone several years of environmental and human selection, and are better adapted to our environment than the high yielding improved varieties,” Dr Zawedde says.
Cassava is increasingly becoming an industrial crop with capacity to transform livelihoods.

Available statistics show that cassava production has been increasing and Uganda is estimated to produce in excesses of 11.3 million tonnes per year down from six million tonnes.
Cassava can be turned into flour for local consumption, ethanol, animal feed, starch for sizing paper and textiles, among other industrial uses.

However, it is threatened by viral diseases, notably cassava brown streak and cassava mosaic diseases that are affecting productivity and resulted into loss of some traditional cassava varieties.

The conservation, Naro scientists say, is aimed at ensuring that farmers have a backup in case they need to plant a variety that is not available in their communities. They add that researchers will be able to use the conserved plants as raw materials to generate more improved crops that are disease resistant and high yielding.

But it isn’t only cassava and potatoes varieties that are disappearing raising more fear for scientists on the future challenges crop breeding industry will face.

Dr Andrew Kiggundu, a researcher at the National Agricultural Research Organisation (Naro), lists some matooke varieties including what is locally known as ndigobe, siira, nakabululu and ndyabalangira that are believed to have disappeared or on the margins of extinction.

Others are kisubi and kayinja, known for their good juice used in the making of local brew (tonto), embidde, kabula, nalukira and nsowe, all of which are of valuable cultural use.
When a variety disappears, Dr Kiggundu says, it becomes a generational challenge for scientists intending to improve a variety, say against a particular disease or infusion of nutrients.

“In order for you to find or produce a new variety, you have to start with large varieties of different individuals (types). The larger the diversity you have, the better you will succeed,” Dr Kiggundu says.

“The more we lose the native varieties, the more we lose the opportunity to improve our crops,” he adds.

Why crop varieties are disappearing

In danger. Cassava tubers roots infected with Brown Streak Disease. PHOTO BY BILL OKETCH

The causes of biodiversity loss, scientists say, are diverse and complex, but they have been noted to include “inappropriate agricultural practices such as overstocking in rangelands; natural disasters and climate change”.

“Pests and diseases; changes in dietary and use habits; pollution; population expansion exacerbating land fragmentation and introduction of new high yielding varieties,” are some of the factors leading to massive extinction of varieties, Dr Zawedde says.

Since 2000, many farmers’ banana gardens have been wiped out across the country by the bacteria wilt, one of the diseases pointed at as the leading cause of biodiversity loss in banana. Cassava has also been attacked by mosaic and cassava brown streak, diseases which too can wipe out entire garden.

As the research organisation grapples with the challenge in a bid to save varieties from extinction, Dr Zawedde says the Plant Genetic Resources Centre (PGRC), better known as Botanical Gardens in Entebbe, is now collecting and preserving varieties for future use.

Naro has further established other centres such as community seed banks and the newly established conservation facility at the National Crops Resources Research Institute (NaCRRI) Namulonge that is conserving vegetative propagated crops such as cassava.

“We, are now trying to do tissue culture conservation where we take tissues of these crops and maintain in a lab at a very low temperature such that they are not growing but they are just there but that is also expensive [to maintaining the lab] Dr Kiggundu says.

“We have a strategic chalenge as a country to maintain these genetic resources but also make them available to breeders or farmers but we need more support,” he adds.

Dr Kiggundu adds: “We are also trying to conserve the DNA [of varieties]. If we completely lose a variety but have its DNA, in future we can learn from it and be able to use it as a genetic resource for breeding.”

Ms Agnes Kirabo, the executive director of Food Rights Alliance (FRA), a coalition of civil society organisations in the field of sustainable agriculture and food security, says it has taken researchers long to arrest the situation since they have talked about this issue for long time.

“It is very good that Naro is now coming up to recognise that these varieties are in danger of getting extinct. We have for decades made noise to conserve these varieties but we were not considered,” Ms Kirabo, said.

“Many of these varieties have been resistant to diseases just like the local cows,” she adds.

Spare the forests

Despair. Hajjat Nuriat Ssebuliba a farmer in Kaaliti village Wakiso district, shows her maize and cassava gardens destroyed by a storm. PHOTO BY JOSEPH KIGGUNDU

Mr Francis Sabino Ogwal, the National Environment Management Authority (Nema) natural resource management officer, says deforestation, which is rampant is another factor that Ugandans should pay attention to if biodiversity is to remain.

He says if people cut down trees, which are homes to pollinator bees, it means many varieties that depend on bees for pollination will disappear because they their reproduction processes will be curtailed.

“Nature was designed to operate as a system. When one variety disappears, you have no idea how many other species that depend on it will also disappear,” says Mr Ogwal. “Nature is so intertwined.”

Dr Jerome Kubiriba of the National Agricultural Research Laboratories (NARL) in Kawanda, says although biodiversity of varieties is important for agriculture production sustainability especially for small holder farmers, it will be inevitable to keep various varieties by farmers.

He says agriculture is now looked at as a business, and therefore farmers will always go where they will reap big as opposed to “sweetness and resistance attached to a particular variety,”

“I think the farmer is currently making rational decision where one can make more money and produce on commercial basis; we should allow the farmers to make the best choices of varieties on the basis of economics,” Dr Kubiriba says.

“If there are varieties that can best serve two objectives, they (farmers) should choose. And I think eventually when farmers become commercially oriented, more varieties will disappear,” adding that there are still many varieties to support breeding.
In a country that is often plagued by malnutrition challenges, any loss of biodiversity of varieties rich in particular food nutrients has several health implications for the young and old, which calls for intensified efforts to preserve the original food species.

Dr Kiggundu says in future, all food processing companies will be required to fortify their products with more than one food nutrient.

“But as biotechnologists, we can use the potential of genetic engineering to enhance the nutrients of our stables. Other things should be fortifications,” Dr Kiggundu argues.
In the recent years, Naro has released a number of improved crop varieties, which are being conserved at NaCRRI and used as parents for breeding.

But whenever Ms Namubiru, her appreciation of agriculture notwithstanding, tastes the products of the improved food crops, her nostalgia for the “sweet” kyebadula she ate while growing up increases.


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