The present dissertation on the topic "Effect of plant growth regulators and phytonutrients on flower and pyrethrins yield in Chrysanthemum cinerariaefolium (Pyrethrum)" was aimed to study the effect of plant growth regulators and phytonutrients on growth, flower yield, enzymes activity, protein and proline content, endogenous hormones (IAA and ABA) and pyrethrins concentration of C. cinerariaefolium using standard procedures. Seed germination studies were conducted to improve seed germination. It can be concluded from the results that application of plant growth retardants (ethrel, chlormequat chloride and paclobutrazol) at appropriate dose significantly increased flower yield and pyrethrins concentration in pyrethrum. Plant growth regulators, especially ethrel is suitable for minimizing lodging in pyrethrum. Plant growth and pyrethrins yield was highest at P75 kg h-1 level and Zn 10 kg ha-1 in north Indian plains. Ethrel, GA3 and pre-chilling treatments improved germination percentage and germination speed in laboratory and glass house conditions. These treatments can alleviate the inhibitory effect of high temperature on pyrethrum seed germination.