Physiological studies on different phases of growth and development in poppy plant (Papaver somniferum) have been undertaken by various workers. These contributions give a better understanding of the development of the plant and its active principles. The physiological maturity of the capsules occurs about 15 days after flowering when it is considered fit for the collection of opium with maximum morphine content. The content of codeine and the baine are reported to be high after flowering. Mika, E. S. reported that on a whole-plant basis the greatest concentration of morphine was found in plants harvested 98 days after germination, whereas the greatest amount of morphine was found in plants collected after 98 and 114 days. Magnesium deficiency brings about a marked elongation of stem and early flowering without a decrease in morphine contents, while calcium deficiency causes a drop in alkaloid contents.