Striga hermonthica, also known as purple witchweed, is an invasive parasitic
plant threatening sub-Saharan Africa's food production. Striga infects the
region's staple crops such as pearl millet, sorghum, and other cereal crops

Striga has an Achilles heel, though. As a parasite that attaches to the
roots of other plants, it dies when it cannot find a host plant to attach
to. Scientists found a way to exploit Striga's Achilles' heel to eradicate
it from farmers' ' fields. A research team from the King Abdullah University
of Science and Technology found that they could trick Striga seeds to think
that a host plant grows nearby. Striga seeds germinate, but do not survive
without a host plant to attach to.

The scientists use plant hormones exuded by plant roots called
strigolactones. These hormones trigger Striga seeds to germinate. By
treating bare crop fields in Burkina Faso with artificial strigolactones,
the scientists found that they were able to reduce the number of Striga
plants by more than half. This method will allow farmers and scientists to
work together to fight the spread of Striga plant, protecting the food
security of 300 million people in the region.

[nph.onlinelibrary.wiley.com]