The formation of agrophytocenoses of sunflower hybrids when using fertilizers in the Middle Volga forest-steppeVasily G. Vasin, Denis V. Potapov, Lyudmila V. Kiseleva, Ramis N. Saniev and Mikhail A. ZhizhinBIO Web Conf., 17 (2020) 00006DOI: https://doi.org/10.1051/bioconf/20201700006