ABSTRACT
Synthetic pesticides are an invaluable component of agriculture, which enhance agricultural productivity because in their absence, heavy losses caused by pests would be incurred. Plant-based pesticides, which are also known as botanical pesticides, have gained increasing popularity because they are "green pesticides", which reduce the pest population, while at the same time being environmentally compatible. The insecticidal value of pyrethrum flower was discovered by the Chinese more than 2000 years ago. This chapter discusses the pyrethrum plant and the oils extracted from it. Special attention is first given to the botany of the plant. Pyrethrin insecticides block the volt-gated sodium channels in nerve axon insects, resulting in a knockdown effect, hyperactivity, and convulsions. The chapter then evaluates the composition of the oil and its physicochemical properties. The general and pesticidal uses are discussed, with their merits and demerits highlighted. Finally, an evaluation of the strengths and weaknesses of the analytical and extraction techniques is made.
