Bio-resourced striga control technologies for african cereal production

Overview

Striga species are parasitic weeds that severely reduce cereal production across Africa, threatening food security for smallholder farmers. Existing control measures are often too expensive, too knowledge-intensive, or harmful to biodiversity. This research program offers bio-resourced alternatives that are cost-effective, accessible, and environmentally safe. Two complementary approaches are being developed: extracts from three local herbaceous plants that induce suicidal germination of Striga hermonthica seeds, and sorghum mutant lines generated through gamma irradiation that resist Striga infestation. Together, these technologies aim to restore cereal yields, reduce reliance on costly chemical controls, and conserve biodiversity in infested farmlands.

Technical specifications

Suicidal germination approach:

• Three locally available herbaceous plants have been identified whose extracts trigger suicidal germination of Striga hermonthica seeds in laboratory bioassays
• When Striga seeds germinate without a host root nearby, the seedlings die, naturally reducing the soil seed bank
• Future work will isolate the active derivatives and optimize field application techniques for maximum effectiveness under screenhouse and field conditions

Genetic resistance approach:

• Sorghum mutants were generated through gamma irradiation mutagenesis
• Two mutant lines have demonstrated resistance to Striga hermonthica across field, glasshouse, and rhizotron screenings
• Ongoing bioassays and in vivo screening will identify the genes responsible for resistance
• Marker-assisted selection and gene pyramiding will combine resistance traits into a single genotype for durable, long-term protection

Key advantages:

• Uses locally sourced plant materials, keeping costs low for smallholder farmers
• Avoids chemical herbicides, preserving biodiversity in and around infested fields
• Combines a biologically based seed-bank reduction strategy with host-plant resistance for integrated Striga management

Technology readiness level

The suicidal germination technology has been validated at the laboratory bioassay stage, with active compounds identified and field-scale application methods still under development. The sorghum mutant lines have progressed further, showing confirmed resistance to Striga hermonthica in field, glasshouse, and rhizotron trials. Next steps include optimizing field application protocols for the plant extracts, continuing molecular screening of the sorghum mutants, and stacking resistance genes through marker-assisted selection. The program is positioned for collaborative field validation and scaling toward smallholder deployment across African cereal-growing regions.