IR maize: Imazapyr resistant maize for Striga management

Boost maize yields while eliminating the issue of Striga infestation

The "Imazapyr resistant maize for Striga management (IR maize)" technology is a maize variety that has been genetically modified to exhibit resistance to imazapyr, an herbicide effective in protecting maize crops from parasitic Striga weeds. These improved maize lines, known as IR maize, have been specifically designed for regions in Sub-Saharan Africa heavily affected by Striga, a parasitic weed that significantly impacts crop productivity by sapping nutrients and water from maize plants. IR maize not only safeguards against Striga but also reduces the growth and negative impact of other common weed types, contributing to improved grain and stover productivity, as well as nutrient and water use efficiency in maize crops. This technology has led to substantial enhancements in food self-sufficiency and economic returns in maize farming across Sub-Saharan Africa.

This technology is TAAT1 validated.

7•7

Scaling readiness: idea maturity 7/9; level of use 7/9

Project adoption

The technology has been integrated into the ENSURE project in East Africa and scaled through the EFPP, PADCV-PTA, and PUPSAN projects in West and Central Africa.

EFPP – Guinea: 35,750 direct beneficiaries, supported via e-Voucher distribution of certified seeds
ENSURE – Regional: 3,000,000 farmers (50% women),, supported through lead farmer training and extension services
PADCV-PTA – DRC: ~900,000 farming households targeted
PUPSAN – Mali: 16,800 producers targeted, with : 30% women, 20% youth, 10% IDPs

EFPP – Guinea: UA 19.39M (~USD 25.23M)
PADCV-PTA – DRC: UA 236.44M for seed capital and scale-up
PUPSAN – Mali: USD 7.040 million
ENSURE – Regional: USD 13.14M

EFPP – Guinea: Nov 2022 – Dec 2024
ENSURE – Regional: 2024–2027
PADCV-PTA – DRC: 2024–2029
PUPSAN – Mali: 2022–2024

EFPP – Guinea: Distribution of 750 t certified seeds + 10 t hybrid seeds; Yield improvement from 1 → 2.5 t/ha
ENSURE – Regional: Adoption facilitated through 3,332 Innovation Platforms
PADCV-PTA – DRC: : 100,000 ha targeted
PUPSAN – Mali: 4,200 ha targeted; Yield increase 2.35 → 3 t/ha; Additional production: 3,780 t

See project details ›

Adults 18 and over: Positive high

The poor: Positive medium

Under 18: Positive low

Women: Positive low

Climate adaptability: Highly adaptable

Farmer climate change readiness: Significant improvement

Biodiversity: Positive impact on biodiversity

Carbon footprint: Same amount of carbon released

Environmental health: Greatly improves environmental health

Soil quality: Improves soil health and fertility

Water use: Same amount of water used

Problem

Severe Striga weed infestations in maize crops, particularly in Sub-Saharan Africa, leading to significant yield losses.
Reduced grain yields and crop productivity due to the parasitic nature of Striga, which competes with maize for nutrients and water.
Limited food self-sufficiency and economic returns in maize farming areas affected by Striga infestations.
Herbicide reliance and the need for effective Striga control methods.

Solution

Development and marketing of improved maize varieties that are genetically modified to be resistant to imazapyr, a herbicide effective in protecting maize crops against Striga weeds.
Introduction of IR maize lines in areas severely affected by Striga, enhancing grain yields and curbing the further spread of the weed when combined with appropriate soil and fertilizer management.
Use of IR maize seeds coated with imazapyr instead of non-resistant hybrid varieties, leading to increased grain and stover productivity and improved nutrient and water use efficiency.
Reduction in herbicide usage for Striga control by precisely delivering the imazapyr agent through seed dressing, effectively inhibiting Striga spore germination near maize roots during the critical stages of crop establishment.
Genetic engineering of maize germplasm to incorporate an 'IR' gene, making maize plants resistant to imazapyr herbicides.
Marketing of maize varieties combining imazapyr resistance with other valuable traits, such as drought tolerance and biofortification.
Season-long protection against Striga on fields, even in areas with varying Striga seedbanks and levels of parasitism of untreated maize varieties.
Compatibility of IR maize with degraded fields and low soil fertility when combined with the appropriate supply of inorganic fertilizers and organic resources.
Use of the non-toxic herbicide imazapyr, which is applied in micro-doses through IR technology.
Coating of herbicides onto maize seeds using a binding agent like Arabic gum, ensuring stable application and effectiveness.

Key points to design your program

IR maize technologies help farmers control Striga hermonthica, one of the most destructive parasitic weeds affecting maize production in Sub-Saharan Africa. By using herbicide-coated resistant seed, the technology protects maize during the critical early stages of crop establishment, reducing Striga infestation while improving grain productivity, nutrient- and water-use efficiency, and farm profitability. It is well suited for food security, sustainable crop intensification, and agricultural productivity programmes, contributing to SDGs 2 (Zero Hunger) and 8 (Decent Work and Economic Growth). The technology also promotes the inclusion of women, youth, and vulnerable rural households through improved access to quality seed and extension services. To successfully integrate this technology, consider the following key actions:

Identify priority maize-growing areas where Striga hermonthica significantly constrains productivity, food security, and farmer incomes.
Establish partnerships with IITA, AATF, national research institutions, seed companies, extension services, farmer organizations, and national seed authorities to strengthen technology deployment and certified seed systems.
Strengthen seed systems by supporting the multiplication, certification, herbicide coating, and distribution of quality IR maize seed while promoting improved varieties adapted to local production conditions.
Promote integrated Striga management by combining IR maize with appropriate fertilizer management, improved soil fertility practices, and crop rotations or intercropping with legumes to achieve sustainable control.
Train extension agents, seed producers, agro-dealers, and farmers on the safe handling and proper use of herbicide-coated seed, integrated Striga management, and recommended agronomic practices.
Strengthen extension services through demonstration plots, farmer field schools, and digital advisory platforms to accelerate technology adoption.
Promote equitable access for women, youth, and vulnerable rural households through targeted seed distribution, technical training, and extension support.
Monitor programme performance through indicators such as certified seed distribution, technology adoption, Striga incidence, maize productivity, farmer income, and the participation of women and youth.

IP

Open source / open access

Scaling Readiness describes how complete a technology\’s development is and its ability to be scaled. It produces a score that measures a technology\’s readiness along two axes: the level of maturity of the idea itself, and the level to which the technology has been used so far.

Each axis goes from 0 to 9 where 9 is the “ready-to-scale” status. For each technology profile in the e-catalogs we have documented the scaling readiness status from evidence given by the technology providers. The e-catalogs only showcase technologies for which the scaling readiness score is at least 8 for maturity of the idea and 7 for the level of use.

The graph below represents visually the scaling readiness status for this technology, you can see the label of each level by hovering your mouse cursor on the number.

Scaling readiness score of this technology

Maturity of the idea 7 out of 9

Semi-controlled environment: prototype

Level of use 7 out of 9

Common use by projects NOT connected to technology provider

Maturity of the idea										Level of use
9
8
7
6
5
4
3
2
1
	1	2	3	4	5	6	7	8	9

Enabling Environments for Sustainable Regional Agriculture Extension (ENSURE)

Project funder: African Development Bank & East Africa Community
Planned Budget: USD 13.14 million
Location: East African Community (Burundi, DRC, Kenya, Rwanda, South Sudan, Tanzania, Uganda)
Planned duration: 2024–2027
Deployment means: On-farm demonstrations, training, digital tools (SMS, IVR, video, radio, pictorial guides), bundled inputs + advisory services, Training of Trainers (ToT)
Project main implementer: East African Community (EAC)
Project Description: Strengthen agricultural extension systems using digital tools, private-sector approaches, regional coordination, and multi-commodity focus (maize, cassava, rice, drought-resilient crops).
Objective: Promote regional extension, enhance advisory services, scale climate-smart technologies, build sustainable private sector–led extension systems, strengthen policy and regulatory frameworks.
Expected outcome: Increased adoption of improved technologies, improved farmer productivity and profitability, enhanced access to quality inputs and pest management solutions, strengthened resilience to climate and pest risks, regional market integration, job creation for youth and agripreneurs.
Figures of adoption: Target 3 million farmers reached over 4 years, digital extension pilots in 7 EAC states, training of extension agents, lead farmers, cooperatives, and youth agripreneurs, rollout of Pest Information Management Systems (PIMS).
Profiles of adopters: Smallholder farmers, women, youth agripreneurs, cooperatives and producer organizations, public and private extension agents, National Plant Protection Officers (NPPOs).
Lessons learnt: System-level approaches needed beyond technology delivery, digital tools most effective with in-person facilitation, supportive policy/regulatory environment critical, regional harmonization boosts scalability and cross-border diffusion of technologies.

Projet d’Appui au Développement des Chaînes de Valeurs en soutien au Programme de Transformation de l’Agriculture (PADCV-PTA)

Project funder: African Development Bank
Planned Budget: USD 311.609 million
Location: 6 provinces in Congo (Kongo Central, Kwango, Maï-Ndombe, Kasaï Oriental, Lomami, Sud-Kivu)
Planned duration: 2024–2029
Deployment means: Direct access to improved seeds and planting materials, seed system strengthening (INERA, SENASEM, multipliers), Farmer Field Schools and demonstration plots (1,600 sites), strengthened public extension (SNV), training/capacity building, subsidized or cost-shared inputs and equipment, irrigation infrastructure (5,200 ha), rural road rehabilitation (600 km), contract farming and private sector partnerships
Project main implementer: Social Fund of the Democratic Republic of the Congo
Project Description: Implements the National Pact for Food and Agriculture (PNAA) using an integrated value chain approach combining technology access (seeds, practices), infrastructure development (irrigation, roads), extension services, farmer organization, finance, and market access to boost productivity, reduce imports, strengthen resilience, and structure agricultural value chains.
Objective: Restore national seed capital, scale improved and climate-resilient technologies, increase productivity, facilitate access to inputs/advisory/markets/finance, promote climate-smart agriculture, strengthen farmer organizations and value chain governance, reduce food imports, and enhance resilience to climate shocks and conflict.
Expected outcome: ~80% crop yield increase (rice, cassava, maize, soybean), 1.68 million tons/year additional production, expansion of irrigated rice, improved access to seeds/inputs, stronger farmer organizations, better post-harvest handling and market integration, increased private sector engagement, reduced food imports, improved national food security.
Figures of adoption: 900,000 farming households directly supported, ~295,000 ha cultivated with improved seeds, 5,200 ha irrigated rice, 600 km rural roads rehabilitated, 1,600 FFS/demonstration plots, 2 million households indirectly benefiting, +4.1 million tons private sector processing, ~1.68 million tons annual production increase
Profiles of adopters: Smallholder farmers, women farmers (100% of women-headed households in target areas), youth/agripreneurs, internally displaced persons (IDPs) in South Kivu, seed producers, cooperatives, farmer organizations/inter-professional associations, public extension services, local authorities
Lessons learnt: Infrastructure (irrigation, roads) and market access are critical for adoption, seed system reform is a bottleneck, contract farming/aggregation incentivizes adoption, combining inputs + extension + finance accelerates impact, governance and institutional coordination are key for scaling and sustainability

Projet d'Urgence de Production et de Sécurite Alimentaire & Nutritionnelle (PUPSAN/AEFPF)

Project funder: African Development Bank (AfDB) Group – Transition Support Facility (TSF) loan and grant
Planned Budget: USD 7.040 million
Location: Republic of Mali
Planned duration: 2022–2024
Deployment means: Distribution of certified seeds and subsidized fertilizers, training for extension staff and farmers on climate-resilient practices, use of digital tools (tablets with Rice Advice and WeedMaster applications)
Project main implementer: Ministry of Rural Development (MDR) via Office Riz Ségou (ORS) and the PDIR-PD2 project management unit
Project Description: Emergency intervention to counter food insecurity by providing climate-resilient inputs, supporting the acquisition of 1,027.14 tons of seeds and 2,234 tons of fertilizers, and assisting national seed policy reforms
Objective: Increase agricultural production and reduce the negative impact of rising food and input prices on the Malian population
Expected outcome: Additional production of 11,145.6 tons of food products, yield increase of 30–50% across targeted crops
Figures of adoption: 35,274 producers targeted, 8,829 hectares cultivated, distribution of 1,027.14 tons of seeds and 2,234 tons of fertilizers
Profiles of adopters: Vulnerable producers including 30% women (10,582), 20% youth (7,054), 10% internally displaced persons (3,527)
Lessons learnt: Leveraging existing execution agencies accelerates startup, efficient procurement systems (advance actions, direct negotiation) are critical, and digitalization ensures transparency and traceability in input distribution

Emergency Food Production Project (Projet de Production Alimentaire d’Urgence - PPAU)

Project funder: African Development Fund (ADF) (Loan and Grant) and the Government of Guinea
Planned Budget: 19.39 million UC (~USD 25.23 million)
Location: Republic of Guinea – national coverage
Planned duration: Nov 2022 – June 2024 (Completion) / Dec 2024 (Closing)
Deployment means: Distribution of certified seeds and fertilizers (30% government subsidy), GAP training, digital platforms (e-Voucher/e-Extension), TAAT technical assistance
Project main implementer: Ministry of Agriculture and Livestock (MAL) via Project Management Unit (UGP) of PATAG-EAJ
Project Description: Emergency operation to mitigate rising input/food prices and boost production of rice, maize, and tubers
Objective: Improve food and nutritional security; increase agricultural production and productivity in intervention zones
Expected outcome: Additional production of 71,429 tons rice, 57,000 tons maize, 12,000 tons cassava; significant yield increases across crops
Figures of adoption: 35,750 direct farmers; 2,000 tons rice seeds, 750 tons maize seeds, 20,000 cassava cuttings distributed; 63,286 ha additional sown area
Profiles of adopters: Smallholder farmers (≥10,750 women – 30%), 1,650 livestock farms, youth entrepreneurs; targeting vulnerable populations
Lessons learnt:
- Constraints: High international input prices, climate vulnerability
- Success factors: Strong existing UGP (PATAG-EAJ), e-Voucher digitalization for transparency, TAAT technical support for rapid multiplication technologies (SAH)

Countries with a green colour: Tested & adopted
Countries with a bright green colour: Adopted
Countries with a yellow colour: Tested
Countries with a blue colour: Testing ongoing

Countries where the technology is being tested or has been tested and adopted
Country	Testing ongoing	Tested	Adopted
Ethiopia	–No ongoing testing	Tested	Adopted
Kenya	–No ongoing testing	Tested	Adopted
Malawi	–No ongoing testing	Tested	Adopted
Mozambique	–No ongoing testing	Tested	Adopted
Tanzania	–No ongoing testing	Tested	Adopted
Uganda	–No ongoing testing	Tested	Adopted
Zambia	–No ongoing testing	Tested	Adopted
Zimbabwe	–No ongoing testing	Tested	Adopted

This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.

Agro-ecological zones where this technology can be used
AEZ	Subtropic - warm	Subtropic - cool	Tropic - warm	Tropic - cool
Arid
Semiarid
Subhumid
Humid

Source: HarvestChoice/IFPRI 2009

The United Nations Sustainable Development Goals that are applicable to this technology.

Goal 2: zero hunger

Goal 8: decent work and economic growth

1. Seed Selection and Preparation:

Obtain high-quality IR maize seeds from a reliable source. Use gloves when handling the coated IR maize seeds to avoid exposure to the herbicide.

2. Soil and Fertilizer Management:

Follow the best soil and fertilizer management practices recommended for your specific growing area and conditions.
Ensure that the soil surface is well-tamped down to help the herbicide reach the surrounding soil.

3. Planting IR Maize:

Plant IR maize seeds as you would with any normal maize crop.
Ensure proper seed spacing and planting depth according to local recommendations.

4. Fertilizer Application:

Apply inorganic fertilizers, with a particular emphasis on nitrogen, as these have been shown to increase yields from IR maize and reduce Striga infestation.
Fertilizer application addresses soil limitations and helps the crop grow stronger.

5. Intercropping or Rotation (if needed):

On farmlands with high rates of Striga infestation, consider intercropping or rotating with food legumes like soybean or cowpea, or forage legume like greenleaf clover.
These additional crops can help manage Striga while diversifying agricultural output.

Last updated on 3 July 2026