MEDICINAL AND AROMATIC CROPS (2+1)

Importance and chemical composition

• The term pyrethrum is applied to the dried flower–heads of Chrysanthemum cinerariaefolium Vis. Family- Asteraceae).
  


• The plant is cultivated for its flowers, whose developing seeds or achenes consist of 3 pairs of esters: pyrethrin I, Cinerin I. Jasmolin I, Pyrethrin II, Cinerin II and Jasmolin II, which are collectively referred to as pyrethrins.
  


• Pyrethrum is one of the safest insecticides known.
  


• It has very low mammalian toxicity and is metabolized if accidentally swallowed.
  


• It disturbs insects forcing them to move out of their hiding places.
  


• It also possesses an instantaneous “Knock-down effect”. It is useful for the preservation of food grains, in the preparation of insect-resistant packaging, mosquito repellent aerosols and coils.
  


• It is an excellent household insecticide.
  


• About 70% of the world’s production finds its way into fly-sprays and insecticidal aerosols, 20% is used in mosquito coils and the balance in other formulations-powder, ointments and creams.