Pyrethrum in Bloom: Bringing Back the Power of Pyrethrum to Enhance Livelihoods of Small Holders in Kenya

Pyrethrum (_Tanacetum cinerariifolium_) is a perennial plant whose flowers are a source of 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. They are the basis of established and globally traded natural plant insecticides. Pyrethrum is the most widely used plant pesticide in horticulture and its use is increasing with \>9000 MT grown in 2016, increasing from only 4509 MT in 2007\. Kenya was formerly the global leader in production contributing 90% of global supply in 1983 with nearly 30,000MT indicating the potential for this technology and scope for income generation among smallholders. Pyrethrin content is variable and dependent upon variety and growing conditions while flower proliferation is dependent on propagation. 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. The aim of this project is to optimise extraction and production and develop innovative pyrethrum formulations that are plant based and sustainable and that benefit smallholder farmers in Kenya through a cooperative movement. The economic benefits will serve as drivers for those farmers and the processing plants to grow once the sector is revived. New organic formulations and processing methods developed during the project will provide new products that incentivise more customers and help to support the continued growth of the sector and sustinjable food production more widely. We believe we can achieve our primary goal of making these improvements to revive the pyrethrum sector during the 36-month timeframe of the project, leaving a sustainable industry.

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 the 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.