Some genetic parameter for maize under different planting dates and environments

"To evaluate the performance of introduced varieties of maize under different sowing dates and locations, in addition to local variety, a field experiment was carried out in two locations;. The study compared five varieties of maize introduced from America, with a local synthetic variety (Ibba 5018) and tested it in two locations at three sowing dates (1, 15 July and 1 August). The Randomized Complete Block Design RCBD was used with four replications, with spilt plot arrangements, the main plots included three sowing dates, the secondary plots included, the varieties. The traits of the days number to tassling and days to silking, plant height, ear height, number of leaves, leaves area, leaf area index, number of ears plant-1 , ear length, the number of rows ear-1, number of grains row-1 , number of grains of the plant, weight of 100 grains, total dry matter weight, the number of days to Physiological maturity, crop growth rate, individual plant yield and yield (tons h-1 ) were studied. The results showed that the values of the standard error (SE) in the two trial locations were low for the studied traits and within the acceptable limit except leaf area which was high in the first and second dates for the Baghdad location and for the three dates of the Diyala incident, as well as the values of the coefficient of variation (CV) were also low and within statistically acceptable limits and for all the traits studied in the three dates and for the two locations. Genetic variations were higher than the = environmental variation for most of the studied traits and the phenotypic coefficient of variation is close to the coefficient of genetic variation for the two locations and the three sowing dates, and this indicates that the traits are genetically governed. The value of heritability in a broad sense was higher than 90% at Baghdad location for first of July for the traits leaves area and its index, weight of the dry matter, number of days to physiological maturity (96.6, 97.4, 93.4 and 94.4%, respectively) and for 15 July for the traits. Leaf area and its index, and number of days to physiological maturity (94.7, 94.7 and 93.4%), and for I Aug for 9 traits; number of days silking, the leaf area and leaf area index, number of ears dry matter, days to maturity, rate of crop growth and yield the plant and unit area ((95.7, 99.4, 99.4, 94, 98.4, 95.5, 98.6, 93.4, 93.5%) Sequentially. As for Diyala, the traits of leaf area, leaf area index, number of days to physiological maturity, yield of plants, and area unit in the three dates were superior to the highest heritability (92.3, 92.3, 98.7, 73.6, 73.6%), (90.2, 90.2, 98.8, 82.9, 82 .9%), (90.9, 90.9, 86.4, 80.7, 80.7% respectively)."