Evaluating the Performance of the Lines and Their Half Diallel Cross in Maize (Zea mays L.) Under Plant Density

Abstract

Two field experiments were conducted during spring and autumn season of 2020, which were carried out at the Research Station of the College of Agriculture, Anbar University, in the first season The lines were introduced into the Half Diallel cross-program according to the second method proposed by [24]. the second season the experiment was applied during the autumn season of 2020 in a split-block arrangement according to a randomized completely -block design with three replications. The main block included the plant density, which was expressed through the distance between the holes. While the secondary block occupied the genotypes (lines + crosses). The results of the analysis showed that there were significant differences between densities and genotypes.The cross 3 × 5 was distinguished by giving the least number of days to tasseling. It also gave the highest plant height 188.60 cm, number of rows / heads 15.5, and the highest yield 19.54 tons / hectare. The cross 1× 5 showed the highest leaf area 5925 cm, while the cross 4×5 and 3×4 showed the highest average number of kernels / row 39.33 and 38.97. The cross 1×4 also distinguished with the highest weight of 300 grains. Cultivated plants with a density 62,500 plants / hectare were distinguished by giving them the fewest days to flower, the highest plant height, leaf area, number of rows, number of grains / row and weight of 300 grains. While the yield was low at 14.93 compared to the plants that cultivated at a density of 125,500 plants / hectare, the reason for this is that the increase in the number of plants per unit area was replaced by the decrease in the yield components.