Researchers’ drive to kick out striga
Jun 14, 2011
Scientists based in Nigeria and Kenya have begun a major push against parasitic weeds that have spread across much of sub-Saharan Africa, causing up to $1.2b in damage every year to the maize and cowpea crops of tens of millions of small farmers.
Scientists based in Nigeria and Kenya have begun a major push against parasitic weeds that have spread across much of sub-Saharan Africa, causing up to $1.2b in damage every year to the maize and cowpea crops of tens of millions of small farmers.
The project, coordinated by the Nigeria-based International Institute of Tropical Agriculture (IITA), will introduce proven technologies for fighting Striga, or witchweed and Alectra. Known by some as the “violet vampire†because of its bright purple colour, Striga attaches itself to the roots of plants like maize and cowpea and sucks out nutrients, reducing yields and destroying entire harvests.
The parasitic weeds have spread widely in Africa in recent decades. Witchweed is difficult to control because each plant produces up to half a million seeds that can remain dormant in the soil for decades.
“Africa is plagued by a plant ‘vampire’ that robs farmers of their harvest,†says Hartmann, IITA director general.
The $9m Striga project is supported by a $6.75m grant from the Bill & Melinda Gates Foundation to IITA. Its goal is to help 200,000 maize farmers and 50,000 cowpea farmers who work in areas with high rates of striga infestation in Kenya and Nigeria. By the project’s end in 2014, organisers estimate that over 250,000 individual farmers will potentially see up to 50% higher maize yields and 100% higher cowpea yields.
The four-year project will focus on improving and expanding access to methods of striga control, while supporting research to identify the most effective means of controlling the parasitic weed under varying conditions.
The project will evaluate and implement four approaches: There is the method of using Striga-resistant crop varieties, using a “push-pull†technology that involves inter-cropping with specific forage legumes that inhibit the germination of striga, using herbicide-coated seeds and deploying bio-control of striga. After a two-year evaluation period, the project will scale up the most effective approaches.
Project partners include the International Maize and Wheat Improvement Centre (www.cimmyt.org), African Agricultural Technology Foundation (www.aatf-africa.org), International Centre of Insect Physiology and Ecology (www.icipe.org), and BASF Crop Protection.
The project will work with farmers, seed companies, community-based organisations, extension workers, policy makers and researchers. In pilot areas, it will supply witchweed-resistant maize and legume seed and chemically treated seed to private seed companies and community-based seed producers for production and distribution.
Prasanna Boddupalli, the director of the Global Maize Programme of CIMMYT, based in Nairobi, Kenya says: “Most farmers in the Striga project target areas are highly resource-poor. The Project aims to integrate delivery of Striga-resistant maize and legume seeds with best-bet agronomic technologies to fight the weed menace, while raising farmers’ awareness of the technologies and supporting community-based organisations with technical assistance.â€
The project will research new management techniques such as the use of a biological control method. Biocontrol can help maintain the balance of nature, support biodiversity and sustain complex and beneficial ecological interactions.
The project will also generate scientific data on the biology of witchweed, including the plant’s relationship with different hosts and methods for rapid screening for resistance to the weed in maize and other crops.
In West Africa, IITA and partners have tested the combined use of Striga-resistant maize varieties in rotation with legumes that cause witchweed seeds to germinate but fail to latch on to the host. This approach increased crop productivity by an average of 88%.
International Institute of
Tropical Agriculture
The Situation in East Africa
Icipe and partners have developed a novel cropping system in East Africa, known as “push-pull.†It is an environmentally-friendly, economical approach that inhibits witchweed and attracts insect pests to trap plants (pull) while driving them away from the main crop using a repellent inter-crop (push).
“Increased uncertainty about the continent’s vulnerability to climate change and its spin-off effects on parasitic weeds like Striga have created more demand for ‘push-pull.’ Farmers need more weapons in the fight against these threats,†says Christian Borgemeister, director general of icipe.
The project, coordinated by the Nigeria-based International Institute of Tropical Agriculture (IITA), will introduce proven technologies for fighting Striga, or witchweed and Alectra. Known by some as the “violet vampire†because of its bright purple colour, Striga attaches itself to the roots of plants like maize and cowpea and sucks out nutrients, reducing yields and destroying entire harvests.
The parasitic weeds have spread widely in Africa in recent decades. Witchweed is difficult to control because each plant produces up to half a million seeds that can remain dormant in the soil for decades.
“Africa is plagued by a plant ‘vampire’ that robs farmers of their harvest,†says Hartmann, IITA director general.
The $9m Striga project is supported by a $6.75m grant from the Bill & Melinda Gates Foundation to IITA. Its goal is to help 200,000 maize farmers and 50,000 cowpea farmers who work in areas with high rates of striga infestation in Kenya and Nigeria. By the project’s end in 2014, organisers estimate that over 250,000 individual farmers will potentially see up to 50% higher maize yields and 100% higher cowpea yields.
The four-year project will focus on improving and expanding access to methods of striga control, while supporting research to identify the most effective means of controlling the parasitic weed under varying conditions.
The project will evaluate and implement four approaches: There is the method of using Striga-resistant crop varieties, using a “push-pull†technology that involves inter-cropping with specific forage legumes that inhibit the germination of striga, using herbicide-coated seeds and deploying bio-control of striga. After a two-year evaluation period, the project will scale up the most effective approaches.
Project partners include the International Maize and Wheat Improvement Centre (www.cimmyt.org), African Agricultural Technology Foundation (www.aatf-africa.org), International Centre of Insect Physiology and Ecology (www.icipe.org), and BASF Crop Protection.
The project will work with farmers, seed companies, community-based organisations, extension workers, policy makers and researchers. In pilot areas, it will supply witchweed-resistant maize and legume seed and chemically treated seed to private seed companies and community-based seed producers for production and distribution.
Prasanna Boddupalli, the director of the Global Maize Programme of CIMMYT, based in Nairobi, Kenya says: “Most farmers in the Striga project target areas are highly resource-poor. The Project aims to integrate delivery of Striga-resistant maize and legume seeds with best-bet agronomic technologies to fight the weed menace, while raising farmers’ awareness of the technologies and supporting community-based organisations with technical assistance.â€
The project will research new management techniques such as the use of a biological control method. Biocontrol can help maintain the balance of nature, support biodiversity and sustain complex and beneficial ecological interactions.
The project will also generate scientific data on the biology of witchweed, including the plant’s relationship with different hosts and methods for rapid screening for resistance to the weed in maize and other crops.
In West Africa, IITA and partners have tested the combined use of Striga-resistant maize varieties in rotation with legumes that cause witchweed seeds to germinate but fail to latch on to the host. This approach increased crop productivity by an average of 88%.
International Institute of
Tropical Agriculture
The Situation in East Africa
Icipe and partners have developed a novel cropping system in East Africa, known as “push-pull.†It is an environmentally-friendly, economical approach that inhibits witchweed and attracts insect pests to trap plants (pull) while driving them away from the main crop using a repellent inter-crop (push).
“Increased uncertainty about the continent’s vulnerability to climate change and its spin-off effects on parasitic weeds like Striga have created more demand for ‘push-pull.’ Farmers need more weapons in the fight against these threats,†says Christian Borgemeister, director general of icipe.