These blossoms are one of the deadliest weeds in Africa, striga, which parasitizes grain crops, attaching itself to the roots of its victim, and sucking the life out of it. As the human population grows and farmers cultivate the same plots of land more frequently, soil fertility dwindles and striga seed builds up in the soil, favoring mass outbreaks of the weed.
A set of 10 videos filmed in 2011 explain how to control striga with practical techniques. The African farmers who star in the videos are graduates of farmer field schools (FFS), and their experience shows. They explain how to recognize striga before it flowers, for example. Farmers are adept at this. While botanists like to see the whole plant with the flower, farmers can recognize weeds from the seedling stage. This is because of farmersâ work experience and also because rural folk use traits other than morphology to identify organisms, such as where the seedling sprouts and when. In the videos the farmers also explain how to uproot striga roots and all, to make sure it doesnât sprout again. These are hybrid ideas that come from farmersâ knowledge blending with scientific information in a farmer field school.
The videos also show a love of African music and landscape, and include shots of the striga weed at different stages, making its life cycle easier to understand. Farmer field schools may be the best way to reveal complex, ecological ideas to farmers, but not everyone can take a field school. By giving the field school graduates a voice on video, the FFS can reach many more people, and give the field school a second life.
To download the videos for free, go to www.accessagriculture.org and enter âFighting strigaâ into the search window. The videos will appear in alphabetical order of their titles. They can be watched in any order, and each one can stand alone, but the ideal topical order is:
1. Striga Biology. How the weed develops from tiny seeds, not from the roots, as many people think. While other weeds are merely bad neighbors, competing for space and nutrients, striga is a true parasite which attaches itself to the hostâs root, then remaining hidden underground for weeks, so it is the last to emerge, and escapes the first weeding at least.
2. Integrated approach against striga. Fertilize the soil with composted manure, because striga damage is worse in poor soils. Add small doses of mineral fertilizer to the base of the plants and intercrop with legumes which kill striga. Hand pull remaining striga plants before they bear seed.
3. Succeed with seeds. How to test crop varieties to find the ones that are the most resistant to striga.
4. Composting to beat striga. Tips on making compost from manure and crop residues in an arid climate.
5. Micro-dosing. Less is more; apply smaller amounts of fertilizer to the base of the plant, instead of spreading it over the whole field. This improves yields and saves money.
6. Animals and trees for a better crop. Livestock can eat the leaves and seed pods of some trees, leaving manure to fertilize crops, especially if farmers establish friendly relations with herders.
7. Storing cowpea seed. Simple ways to keep seed healthy, so the household has enough seed to intercrop cowpea with cereals.
8. Grow row by row. Cowpeas and other legumes are trap crops which stimulate striga to germinate, but not to attach to the hostâs roots. Intercropping and rotating with legumes kills the striga seed in the soil.
9. Joining hands against striga. Weeding is pretty boring work, but farmers can beat the drudgery by working together. This is basically labor exchange, a time-honored practice in Africa and elsewhere. Advice for farmers should show respect for all good ideas, old and new.
10. Letâs talk money. A brief view of costs and benefits. Managing striga costs more, but the bigger yields are worth it.
All 10 videos have sound-tracts in English, French, Arabic, Portuguese and 18 languages of Africa, including Swahili, Chichewa and Hausa.
The videos were developed by ICRISAT, and funded by EU IFAD (Promiso Project) and by the Bill and Melinda Gates Foundation. They were made by Eva Weltzien, Marcella Vrolijks, Paul Van Mele, Sidi Toure, Tom van Mourik, and many others. They were filmed in Mali, Tanzania, Ghana and Nigeria, and produced by Agro-Insight.
Based on the wide-scale impact of these videos, Agro-Insight received the Industry Award for Communication Effectiveness from the prestigious International Visual Communications Association in London on March 28th, 2014.
See related stories in: New Agriculturalist
http://www.new-ag.info/en/research/innovationItem.php?a=2513
and in: Nourishing the Planet
http://blogs.worldwatch.org/nourishingtheplanet/fighting-striga/