Photosynthetic activity is the decisive factor of yield increase in sunflower plants. This activity determines the application of agrotechnical measures such as row spacing and plant density. Experiments have proved that agrotechnical measures allow to control the growth, development and yield of sunflower hybrids and varieties. Row spacing and plants density affect the index of photo synthesis and the yield of sunflower agrophytocoenoses. Cultivation of sun flower at the row spacing of 15 cm in different variants of plants density increased the yield of the hybrid Zaporozhskiy 9 by 0.11-0.70 t/ha, of the hybrid Kharkovskiy 58 by 0.62-1.1 t/ha, of the variety Lider by 0.24-0.59 t/ha, of the variety Prometey by 0.20-0.63 t/ha as compared with the cultivation in agrophytocoenoces at the row spacing of 70 cm.