TY JOUR TI Assessment of competitiveness of sunflower hybrids of different maturity groups KW sunflower hybrids KW contamination of crops KW weeds KW species composition KW maturity groups KW yield KW critical period of harmfulness JO INTERNATIONAL AGRICULTURAL JOURNAL AU Mamsirov, N.I. AU Khanieva, I.M. AU Tkhakushinova, L.N. PY 2025 IS 0 PB Electronic science