Combining ability of qpm inbred lines for days to tasseling and silking

Tasseling and silking times were studied in 10 QPM inbred lines and their 45 single cross hybrids at Rajendra Agricultural University, Pusa (E₁), Research Station, Madhopur (E₂) and Research Station, Manjhi (E₃) of Bihar. General combining ability (GCA) variances were significant for days to tasseling and silking in E₁ and E₂ environments but not in E₃ environment. Specific combining ability (SCA) variances were significant for days to silking in all environments. For days to tasselling SCA variances were significant in E₁ and E₂ environments but not significant in E₃ environment. The small values of ratio (s² GCA/s² SCA) indicated preponderance of non-additive genetic variance in days to tasseling and silking. Fifty percent of the specific crosses showing high SCA were from parents having average general combining ability.