Summary: In Congo, rice yields remain low. To better determine the productivity of the panicle in rice varieties, following the different treatments of the mineral nutrition background, it was established that there is a considerable influence of the contributions of nitrogen and carbon compounds coming from the vegetative organs of the plant. Methodology and results: Three treatments were applied (N12 P6 K6), (N24 P12 K12) and (N 36P 18K18) on the two (2) varieties Nerica 14 and Nerica 12. Sowing was carried out according to stencils with the creation of the same density plants 250-300 grains/m2. The results show that the varieties studied react differently to a high level of mineral nutrition (N36 P18 K18). Increased photosynthesis productivity can be seen in the upper leaves, which transmit more light deeper into the crop. Conclusion and application of results: The most favorable nutrition of a developing panicle, balanced in terms of carbon and nitrogen, is observed when the ratio of carbon to non-protein nitrogen in its tissues is equal to 30 - 40 units.