Pest management restores mango markets in Southern Africa

Mangoes are a high-value horticultural crop and an important source of nutrition in Southern Africa. However, 80% of mangoes are lost to fruit flies, hampering mango productivity at the local level as well as curtailing export opportunities. Synthetic insecticides are largely ineffective in controlling these pests.  

To improve food and nutrition security, income-generation opportunities and the livelihoods of horticultural farmers working in the mango value chain, a Cultivate Africa’s Future (CultiAF) project developed and validated a fruit fly integrated pest management (IPM) package.  

Following several years of testing, the package was launched in 2019 in four Southern Africa countries: Malawi (Salima, Lilongwe and Ntcheu districts), Mozambique (Manica and Inhambane provinces), Zambia (Rufunsa and Chilanga districts) and Zimbabwe (Murehwa, Mutoko and Zvimba districts). The project, called Alien invasive fruit flies in Southern Africa, aimed to distribute the package of technologies, such as fruit fly lures and traps, to resource-poor men and women farmers, and raise awareness of IPM across the region.  

Outcomes

Fit-for-purpose interventions 

Farmers in the four project countries received IPM starter packs containing five interventions. These included fungal biopesticides, which contain natural toxins that kill the flies, and protein food baits (food injected with insecticide), which are placed inside small plastic “bait stations”. The stations are hung from mango trees where they attract and kill the flies. A further intervention included male annihilation, which uses lures, such as attractants, to draw in and kill male fruit flies. This significantly reduces mating and production of fertilized eggs.  

Farm cleanliness is also part of the IPM package, whereby farmers are encouraged to gather infested mangoes and bury them. In this intervention, farmers were also encouraged to use a tent-like structure known as an augmentorium to store fallen, infested fruits. These structures were provided by the project and are fashioned out of plastic or netting. Fruit flies are too large to pass through the netting, and become trapped and die.  

“I learned that fruit flies destroy mangoes, resulting in a loss of income for me. I now use lures to attract male flies to a poison, eliminating fly reproduction. IPM is effective and helpful,” said Sailor Chimbwali, a mango farmer from Chilanga District, 40 km from Zambia’s capital city, Lusaka. 

The final IPM intervention was the use of parasitoids (small, wasp-like insects). As natural enemies of the fruit flies, parasitoids lay their eggs inside fruit fly eggs and larvae, where they develop and eventually emerge, killing the fruit fly in the process. Since 2019, the International Centre of Insect Physiology and Ecology (icipe), based in Nairobi, Kenya, has released more than 22,000 parasitoids that control fruit flies at the egg stage and 24,000 parasitoids that control the fruit flies at the larvae stage. To promote sustainability and avoid reliance on icipe in the future, the research team established rearing facilities in all four countries. Mozambique and Zimbabwe have managed to establish colonies of the wasps, while Malawi and Zambia are in the process of doing so. 

Partners implementing various activities under the project include Malawi’s Department of Agricultural Research Services, Eduardo Mondlane University in Mozambique, the Zambia Agriculture Research Institute and the Department of Research and Specialist Services in Zimbabwe. 

Scaling out the benefits 

Since the research launched in 2019, the IPM technologies have been demonstrated at 52 farmer fields: 15 each in Malawi and Mozambique, 10 in Zimbabwe and 12 in Zambia. Each hosting farmer received training to relay information about IPM technologies to other farmers. In total, 17,578 men (53%) and women (47%) received training to use the technologies — more than five times the project target. At the beginning of the project, only 7% of farmers in target areas were aware of fruit flies; this increased 12-fold to 89% by the end of the project. 

The use of the IPM technologies saved seven out of 10 harvested mangoes. Farmers — both men and women — increased their mango income and were able to diversify their farms by cultivating new crops. “In the second year of implementing the fruit fly IPM package, we managed to sell clean mangoes in bulk to traders. With the proceeds, I was able to afford maize seed to diversify my income sources,” explained Emily Chakanyuka from Murewa in Zimbabwe. The reduction in fruit flies is also improving the production of other fruit (papaya and passion fruit) and vegetable crops (squash, pumpkin and butternut). 

Participatory farmer groups (10 to 20 per country), which include agricultural extension officers, local farmers and traditional leaders, were set up by the project to encourage regular meetings to discuss IPM strategies. In Zimbabwe, the groups have established mango-grafting activities (a rapid propagation technique used to multiply plants). Members of farmer groups are also pooling their financial resources to diversify into other income-generating activities. In Malawi, for instance, the Linengwe women’s group in Mpingu EPA District pooled its mango income to provide loans to friends, with interest to increase their savings.  

Dried mango markets 

Adoption of IPM packages in the target countries resulted in increased yields of quality mangoes for the smallholder farmers — a positive outcome. However, when COVID-19 hit and lockdown measures were implemented, the farmers had no access to markets, meaning their excess harvest was wasted. To address this problem, the project pivoted its research to develop an innovation — solar-drying baskets — that would allow the farmers to preserve their crop.

Fashioned out of woven polyester netting material wrapped around wire frames, the baskets have between three and seven sealed shelves on which to dry the fruit. The mangoes are cut and placed in the baskets with no preservatives to dry in the sun, which takes up to a day. Provided it is stored in a dry place, the dried mango can be preserved for more than a year, which provides an additional source of food to farmers in the dry season, as well as a new income stream.  

In Zambia, a basket of fresh mangoes fetches 100 Zambian Kwacha (ZK), or CAD7.00, while a basket of dried mango costs ZK 800 (CAD65). In Zimbabwe, 100 g of dried mango costs 19.35 Zimbabwean dollars (ZWL), or CAD1.30 but, when well packaged, 35 g can be sold for between ZWL 14.5 (CAD1) and ZWL 19.35 (CAD1.30). The dryers were also used by women for drying vegetables, such as tomatoes and onions, for household consumption. In Zambia, 28 farmers (27 women and one man) were trained to make the inexpensive dryers, which were supplied to 450 women. In Zimbabwe, 5,982 men and women received training in drying mangoes and making basket dryers.  

For farmer Emily Chakanyuka in Zimbabwe, the training paid dividends. “I dried a good quantity of mangoes in February [2022] and realized up to ZWL 2,545 [CAD194] from what I sold,” she revealed. “I am happy to have learned how to dry mango because it is a tasty food!”  

Nyepudzai Kamundi from Mutoko District in Zimbabwe agreed. “My family loves mangoes and I feel sad that I have denied them this delicacy because I prepared very little of it previously. I have also taught other farmers how to dry mangoes and those who have tasted them really enjoyed them.”  

Conclusion 

The IPM project technologies have proven highly effective in the target region, with significant outcomes for local communities. The combination of sensitization activities through technology demonstrations, access to the IPM package and links to new markets has reduced poverty and increased the food and nutrition security of project beneficiaries. Bringing groups together within communities further strengthened financial resilience through the pooling of resources to enter into new agricultural enterprises — a particular benefit for women’s groups. Women also benefitted from mango-drying training, as they carry out this activity more than men. The dried mango provides an additional income source and off-season nutrition, as well as addressing post-harvest mango losses.  

To further scale the technologies in future, the project has recognized the need for the IPM tools and solar dryers to be produced locally rather than relying on imported materials. However, sustained demand and appreciation for the package will be necessary to engage local manufacturers and agri-dealers. 

Cultivate Africa's Future, a 10-year, CAD35-million partnership between IDRC and the Australian Centre for International Agricultural Research, funds applied research aimed at improving food security, resilience and gender equality across Eastern and Southern Africa.  

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