Determination of Genetic Coefficients of Some Maize (Zea mays L.) Cultivars of Iran for Application in Crop Simulation Models

A field experiment was conducted at the research field of the University of Lorestan in 2011 as a randomized complete block design with three replications to estimate genetic coefficients of some maize (Zea mays L.) cultivars. Treatments include six maize cultivars (T.V.C.767 and S.C.704 from late maturing group, T N.S640 and Maxima from mid-maturing group, and Koppany and D.C.370 from early maturing group). Results showed that there were significant differences among cultivars in terms of stem dry weight, maximum number of kernel per ear, thermal time from the flag leaf appearance to flowering, thermal time from flowering to maturity, phyllochron interval, grain weight, maximum plant height and minimum growth degree days during vegetative period. The highest (649.2) and lowest (350.6) maximum number of kernel per ear belonged to cultivars S.C.704 and D.C.370, respectively. Also, the highest and lowest stem dry weight, phyllochron interval and maximum plant height belonged to cultivars S.C.704 and D.C.370, respectively. Among genetic coefficients, the minimum growth degree days required for vegetative growth and the maximum number of kernel per ear had the greatest correlation with grain yield (r=0.72 and r=0.84, respectively). Overall, the results portrayed that the estimated genetic coefficients of the cultivars are not identical in different models and varied in a defined range.