Evaluation of the Performance of Single Cross Maize Hybrids and Their Parents in the Spring and Autumn Seasons

Abstract

Abstract A field experiment was conducted using five pure lines of maize: 1= NADH 102, 2= NASA 2022, 3= NAEL 2022, 4= NA 9928 E, and 5= NADH 2006. In the first season of spring 2022, a half-diallel hybridization program was implemented to obtain (10) single cross hybrids. Then, the parents and single cross hybrids were planted in a comparative experiment in the fields of the College of Agricultural Engineering Sciences - University of Baghdad / Jadriyah during the spring and autumn seasons of 2023 following a randomized complete block design with four replicates. To study the number of days to tasseling, plant height, leaf number, leaf area, row number, grain number per row, ear length, ear number, weight of 100 grains, and individual plant yield, the results of the study revealed significant differences among the genotypes. Parent 1 recorded the highest plant yield at 289.90 and 297.46 grams plant-1 for both seasons due to its superior weight of 100 grains (25.71 and 26.41 grams) for both seasons. Parent 3 did not differ significantly from parent 1, with a yield of 260.00 and 280.23 grams plant-1 for both seasons respectively, due to its superiority in the highest number of ear rows, grain per rows, and ear grains (18.16 and 18.25 rows ear-1, 30.75 and 32.08 grains row-1, and 559.1 and 585.1 grain ear-1) respectively for both seasons. Among the hybrids, the single cross hybrid (4×2) excelled with the highest plant yield at 427.64 and 450.44 grams plant-1 due to its superiority in plant height and weight of 100 grains (186.75 and 215.37 cm and 29.89 and 28.05 grams) respectively for both seasons. Similarly, the hybrid (5×1) did not differ significantly from hybrid (4×2) with a plant yield of 425.60 and 432.44 grams per plant respectively for both seasons, due to its early tasseling (56.00 and 46.00 days) respectively for both seasons. It also excelled in the number of grains ear-1 (547.2 and 581.4 grains ear-) respectively for both seasons. We propose studying single cross hybrid at different planting dates to demonstrate their ability to adapt to the Iraqi climate and to test them under stressful conditions such as drought.