Thermal Accumulation for Tasseling and Silk Stages and Yield Components for Corn Genotypes Growing in Planting Dates Autumn Season

Abstract

Abstract An experiment was carried out on the extension farm of the extension center in Baladruz district in the fall season of 2023, with the aim of studying nine varieties of corn, namely (Al-Maha, Cadz, American Miami, American BioNTech, Ronaldino, PC Serbian, TORRO, KWS and German Deco Nester) with three planting dates (20 June. 5 July and 20 July). Using Randomized Complete Block Design in a split-plot arrangement, the main plots included planting dates while the varieties were in the secondary plots. The results showed that the Ronaldino variety was superior in terms of the lowest number of days to tasseling and silk, and the thermal accumulations to tasseling and silk reached (46.0 days, 52.3 days, 1249.0°C, and 1402.1°C), while the German Deco Nester excelled in the number of grains per row, which reached (33.9)grains, and Torro Variety in weight 500 grains (170.9) grams, and excelled The two variety Kws and German Deco Nester had a fertility rate of (90.0% and 92.2%). The PC Serbian variety was superior in grain yield,(9033) kg ha-1. As for planting dates, the planting date of 20 July was superior in most of the studied traits, Ronaldinho recorded the lowest number to tasseling and silk in 20 July (45.0 days, 51.0 days), and the thermal accumulation for them was (1247.7)C °and (1280.2) C°, respectively. It is noted that the German Deco Nester was superior in yield in all planting dates due to the high fertility rate and its excellence in grain yield components.