The parasitic weed Striga hermonthica, commonly known as witchweed, is one of the main pests devastating cereal crops in sub-Saharan Africa, where it can cause an estimated 40-80 percent yield loss in pearl millet and sorghum. This parasite thrives
in fields with very low soil fertility and frequently cultivated with cereals. It attaches itself to the roots of pearl millet, sorghum, maize, rice and other cereals, and sucks the nutrients out of healthy plants causing widespread damage.
Witchweed infestation can be very rapid if not properly managed. A single mature witchweed plant can produce up to 200,000 tiny dust like seeds that can easily spread via contaminated crop seeds, farm tools, wind, water and animals, and can stay viable
in the soil for up to 10 years or more.
To try and tackle this, farmer communities are now sharing tried and tested ways to control witchweed via video.
“If I control witchweed in my fields, my neighbours need to do the same in theirs. Otherwise my efforts will be in vain when it rains heavily because rainwater will wash
Striga seeds into my plot. So for a good result you and your neighbour must work together to fight against witchweed,” says farmer Christine Keita, one of many farmers who share their experience on video. Managing this pest therefore calls for widespread
community action using well researched methods adapted to smallholder farmers.
The witchweed problem is nothing new as scientists have been studying ways to control it for almost 40 years. To get this research out to farmers in West Africa, the
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and partners have developed an integrated set of
Striga and soil fertility management practices (ISSFM) that farmers can adapt to sorghum and pearl millet, which are traditional crops important for food security and income for farmers in this region.
This kit, or
Striga pack (photo to the right), covers a plot of 6700 square feet (.06 hectares) and has been produced as part of the foundation funded
project Hope (“Harnessing Opportunities for Productivity Enhancement of Sorghum and Millets), to encourage smallholder farmers to experiment a new way of cultivating cereals on their farm and see the results for themselves.
It includes “Toronion” or improved pearl millet seeds, Dunanfana (cowpea seeds), di-ammonium phosphate to apply as fertilizer during sowing and first weeding, urea, and an information leaflet explaining what needs to be done to manage soil fertility and witchweed.
The key is that it’s affordable, costing 1500 francs (just under $3), making it accessible for farmers.
Since the early 2000s, ICRISAT scientists and partners in West Africa established “farmer field schools” to test combinations of witchweed
control practices and share them among farmers. This reached out to a hundred farmers at a time. Still, given the scale of witchweed damage in West Africa, researchers needed to come up with efficient ways to train not hundreds but thousands of smallholder
farmers to fight the parasite.
Scaling up, farmers talking to farmers
And what could be better than
farmers spreading the word via video to other communities? ICRISAT has partnered with farmer field school groups in Ghana, Mali, Niger, Nigeria, and Tanzania, and with development organisations, local extension workers and professional video film makers,
to produce a series of ten farmer-friendly videos on 'Fighting Striga'. Each video focuses on a different aspect of weed management using farmer feedback, including testing different seed varieties for their resistance to witchweed, adding compost to soil
and intercropping cereals and legumes to improve soil fertility (witchweed develops in very poor soils), and the importance of community effort to eradicate witchweed.
Videos were produced in French and English but also in West African national languages : Bambara, Bomu,Fulani Hausa, Mooré and Zarma, and a Swahili version will soon be out for Eastern Africa. They can be freely downloaded on the following website http://www.accessagriculture.org/#
which serves as a rich resource for groups working with smallholder farmer communities.
The 10 minute videos are a valuable interactive training tool for farmer field schools, rural radios, or other training initiatives by farmers’ cooperatives or extension services, and generate lively discussions. New communication technologies may further
help disseminate this vital information; why not via mobile phones?
The key is that farmers were fully involved in the film making process. They are proud and motivated to share their experience with other farmers, and farmers watching these videos relate easily to the content, making the learning process more enjoyable
Witchweed control research and video production have been supported by several donors : Bill and Melinda Gates Foundation, Aga Khan Foundation, IFAD and EU Food Initiative for West Africa.