Pyrethrum in Bloom: Bringing back the power of pyrethrum to enhance livelihoods of small holders in Kenya

Developing plant-based formulations and environmentally benign extraction procedures for pyrethrum and reinvigorating the pyrethrum sector in Kenya

Flowers of Tanacetum cinerariifolium that look very similar to daisy

Pyrethrum (Tanacetum cinerariifolium) is a perennial plant in the daisy family (Asteraceae).

The flowers are a source of naturally produced bioactive pyrethrins widely recognized for their rapid knock down of insect pests in horticulture but having very low mammalian toxicity and non-persistence in the environment.

Pyrethrum cultivation in Kenya dates to 1928 when Capt. Gilbert Walker of the Imperial Institute (now our collaborating partner Natural Resources Institute) took some specimens from Royal Botanic Gardens, Kew.

Pyrethrum is now the most widely used botanical pesticide in horticulture. Pyrethrum active compounds are pyrethrins, which have rapid insect knockdown effect.

While pyrethrum is plant based, the use of toxic solvents for extraction and inclusion of synthetic additives as stabilizers, synergists and carriers in formulations means it is not suitable in organic farming so new plant-based synergists and carriers are required. 

Kenya was formerly the world’s leading producer of pyrethrum providing important foreign currency for Kenya but also important revenue for small holders.

The aim of this project is to optimize extraction and production and develop innovative pyrethrum formulations that are plant-based and sustainable and that ultimately benefit smallholder farmers in Kenya through cooperative movements.

New organic formulations and processing methods developed during the project will incentivize more customers and help to support the continued growth of the sector and sustainable food production more widely. 

This project will achieve the following outcomes:

  1. Develop high quality propagules using improved in vitro germination procedures to guarantee axillary shoot multiplication and rooting to optimise pyrethrin content of flowers.
  2. Develop an organic method for pyrethrin extraction based on ethanol and ultrasound.
  3. Develop new plant oil-based solvents (excipients) e.g. from Croton megalocarpus readily available and indigenous in Kenya, to replace synthetic Shell Sol(r) T oil.
  4. Develop new formulations using plant oils/synergists to replace piperonyl butoxide; and plant-based stabilizers e.g., from Salvia rosmarinus to replace butylated hydroxytoluene
  5. Identify and work with key pyrethrum stakeholders and register a pyrethrum-based product for Kenyan organic farming via a farmer cooperative.

Kevin Stephens & Bryan Shand (Bio extractions, Wales)

Prof Josiah Omolo & Prof Paul Kimurto (Egerton University, Kenya)

Dr Mandela Fernandez Grandon (Natural Resources Institute, University of Greenwich)

Belynda Mbuu (JatFlora Ltd, Kenya)

Xavier Bowen & Joyce Macharia (GrowTech Nurseries Ltd)

Innovate UK Agritech Catalyst