THE EFFECT OF SOWING DATES AND SEEDING RATES ON YIELD AND PHOTOSYNTHETIC ACTIVITY OF LEAVES OF SPRING WHEAT SEEDLINGS

The article presents the results of research on the influence of sowing dates (May 15 and 22) and seeding rates (4.0, 4.5, 5.0 million grain per hectare) on the yield and leaf surface area of seedlings of spring wheat varieties - Krasnoyarskaya 12, Kanskaya and Novosibirskaya 31. The experiments were conducted in the Yemelyanovsky district of the Krasnoyarsk Territory in 2021-2023 yy. In the second sowing period, the yield of all varieties increased by 0.1-0.3 t/ha compared to the first, the height of seedlings and the area of leaves increased by 0.4-1.4 cm and 0.2-0.4 cm2, respectively. With increased seeding rates, the productivity of wheat varieties was formed by 0.4-1.2 cm2 higher compared to sparse crops, while there was no connection with the leaf surface area.