Dar es Salaam — University of Dar es Salaam (UDSM) scientists have been conducting research on yams and taros to assure farmers of supply of seedlings to increase production.
This is important taking into account the fact that poor crop varieties, bad farming methods and outdated technologies have been hindering agricultural development.
Yam and taros have been given little attention by authorities and are therefore under-researched despite being highly demanded by consumers.
Scientists say the crops are drought-resistant and can easily withstand climate change.
They are less vulnerable to pests and can thrive even without fertilisers. The project on improving yam and taro productivity in Tanzania is being undertaken by the Department of Molecular Biology and Biotechnology of the College of Natural and Applied Sciences.
Under the project funded by the Tanzania Commission for Science and Technology (Costech), plant parts such as stems or small parts of leaves are exposed to plant nutrients and light under clean conditions known as micropropagation or tissue culture to produce many seedlings over a period of up to three months.
Since no genes are modified, the technology is different from genetic engineering.
Nigeria is the global leading yam producer, accounting for over 70-76 per cent of the world production, according to reports.
The country has adopted the technology.
In Tanzania, yams and taros are mainly cultivated in Kilimanjaro, Morogoro, Kagera, Coast Region, Arusha and Zanzibar.
But poor technology has hindered cultivation.
A project principal investigator, Dr Gladness Temu, told The Citizen during the Third UDSM Research Week recently that the technology is potential for massive production of seedlings in 1-3 months. Thus, farmers' challenges can be solved.
She said the two-year project started in June 2015.
Other organisations involved in it are the Root and Tuber Crops Section of the Sugarcane Research Institute Kibaha (SRI-Kibaha), Zanzibar Agricultural Research Institute (Zari) and Mikocheni Agricultural Research Institute (Mari).
Costech finances it under the National Fund for Advancement of Science and Technology.
Use of tissue culture
The idea of using tissue culture to produce yam and taro seedlings came out because Dr Temu used a similar approach using cassava during her PhD studies.
Dr Temu is currently a senior lecturer in biotechnology.
During the ongoing project, the scientists realised that yam and taro farmers faced difficulties in getting improved varieties and planting materials.
The situation has led to poor production while the demand is high.
The majority of people living in coastal areas, where the study was conducted, like eating taros and yams, especially during the Holy Month of Ramadhan.
Yam is also among the types of food recommended for diabetics.
The project is traced back to 2014 when Costech announced a call for proposal on leveraging technologies for social economic transformation.
Dr Temu promptly sent her project proposal. The competition was tough as out of over 100 researchers only 21 were selected. "Mine was among them and that's where the journey started," she recalls.
Before they started the project, they conducted a baseline survey in Mkuranga, Rufiji and Zanzibar where the crops are grown.
"Basically during our survey farmers and local government officials were surprised because it was their first time to see or hear a researcher or government talking about yams and taros."
Since farmers have no any improved varieties in those areas, production is extremely low while the demand is high.
How the technology works
Using the micropropagation approach, up to 16 planting materials can be attained from a single tuber of taro; while for yams up to 500 seedlings can be attained from the same single plant using vine nodal cuttings.
The technology is simple: even farmers can use it if they are trained.
According to Dr Temu the great challenge that researchers face is the huge demand for seedlings compared to duration and amount of funding of the project since all over the visited areas farmers are want them.
Currently the trials are at the greenhouse at Mari and field trials at SRI-Kibaha.
The researchers intend to distribute the seedlings to coastal farmers in August 2017.
Farmers have been planting rotten tubers due to the lack of seedlings.
The university has benefited through generation and expansion of networks and links of collaborators, visibility especially in solving community problems and capacity building whereby the established platform of knowledge can be used by other students and researchers.
Contribution to industrialisation
Industrialisation and research cannot be separated. Through research, technologies are developed. Using cost-effective technologies like micropropagation to provide practical solutions to long-term farming problems will ultimately increase incomes.
"Moreover, how can think of industrialisation if a farmer is worried about food insecurity?" says Dr Temu.
According to Dr Temu, during a conference on roots and tuber crops early this year Ghanaian and Nigerian researchers congratulated Tanzania on its efforts of improving yam and taro production.
During the recent UDSM Research Week, a number of visitors to Dr Temu team's pavilion were interested in what was going on and wanted to know how to get yam and taro seedlings.
The government responded to farmer's problems through studies and thus the researchers hope to get more funding to extend the project to cover the whole country.
Mr Julius Mtweve speaks highly of the research findings, saying the technology has come at the right time when farmers are unsure of where to get proper seedlings for yams and taros.
"The technology will help farmers a lot because I have been told that they can also produce seeds themselves using a small laboratory. I call upon the government to roll out the project countrywide as we cannot realise our industrialisation dream without research," he said.
UDSM's Dr Richard Maganga said more funds was needed to reach out more farmers. "Taros and yams don't need fertilisers and consumers like them."
Patterns of yam cultivation and consumption in Tanzania
In Tanzania, varieties of yams grown include Vigonzo, Mahombo, Mahole, Buyu, Tona, and Vitungi with the major growing areas being Mtwara, Morogoro, Kibaha, Kondoa, Arusha, Mwanza and Zanzibar.
The highest volume of 9,800 tonnes was realised in 2011.
Other varieties grown in Mtwara and Newala districts are Vinyamilwa, Mhoko, Mkonga wa nembo, Hangadi, Hamandeke, Vitundi, Luvale, Matu, Mnyuvele and Vyekundu.
Harvesting is done by women.
Yams take six to 12 months to mature, depending on variety.
Generally, yams have a relatively higher cost of production than other root crops because they require staking in many areas, greater labour input for land preparation (clearing and mounding), stake-tying, weeding and careful harvesting. These labour requirements exceed those for other starchy staples such as cassava, accounting for about 40 per cent of yam production costs while 50 per cent of the expenditure goes to planting materials.
The yam is mainly consumed raw or boiled, baked or fried.
The tubers may also be mashed or pounded into dough after boiling, processed into flour, or cooked into soup with added protein sauce and oils.
There is little processing of yams in Tanzania and Uganda, with only one processor having been identified in this study.
Besides production, producers also undertake a number of other activities including marketing and storage. They also participate in training. There are more producers in Tanzania than Uganda who access improved planting materials. Yams are mainly sold in raw form and to small amounts as flour and dried chips in Tanzania and Uganda.
Among retailers in Tanzania, Uganda, Kenya, Burundi and Rwanda, prices are mainly determined by market forces, negotiations.
Market forces of demand and supply are the key determinants of prices for 80 per cent of retailers in Tanzania.
Between 2003 and 2011, yam production increased in Tanzania. It reached 9,800 tonnes in 2011.
Productivity climbed to 6.6 tonnes per hectare in 2011, up from 4.9 tonnes per hectares in 2009.