The research was carried out with aim of examined effects on seed and capsule yield with some alkaloid contents of fertilize with nitrogen treatment from leaves in different development stages of poppy in Isparta conditions in the 2021 year. In the research, in the TMO1 poppy variety, 1. Control (no N fertilizer), 2. traditional production (half of the nitrogen during sowing and the remaining half during rosette period), 3. stalking period (1/3 of nitrogen during sowing, 1/3 from soil during rosette period, 1/3 from foliar application during the stem period), the 4th budding (1/3 of the nitrogen during sowing, 1/3 from the soil during the rosette stage, 1/3 from foliar application during the budding period) and the 5th post-flowering periods (1/3 of nitrogen during sowing, 1/3 from soil during rosette period and 1/3 foliar application after flowering). According to the research results; While the differences between plant height, number of capsule, capsule width, and capsule length were not significant, the differences between seed yield, capsule yield, nitrogen use efficiency were statistically significant, and as general, it was advised to nitrogen treatment from leaves for capsule yield, seed yield and nitrogen use efficiency.