Evaluation the performance of tree-way crosses of maize under different sowing dates in fall season

تقييم الأداء لتضريبات ثلاثية من الذرة الصفراء Zea mays L. تحت تأثير مواعيد الزراعة في العروة الخريفية

Abstract

 The present study aimed to evaluate the performance of three-way crosses of maize and testing them under different planting dates and estimate their genetic parameters. A field experiment was conducted at Station A in the College of Agricultural Engineering Sciences at the University of Baghdad/ Al-Jadriyah during the fall season of 2022.The experiment followed a split-plot arrangement based on a randomized complete block design (RCBD) with four replications. The main plot included three planting dates (15 July, 25 July, and 5 August), while the sub-plot consisted of six superior three-way cross hybrids and the local cultivar control (Fajr 1).The results showed that July 25th was the most superior planting date with regards to yield (8.55 ton h^-1) due to its superiority in various characteristics such as plant height (205.83 cm), leaf area (6767 cm²) ear weight (195.1 g. The Three way cross (1×3) ×2 excelled with the highest yield per unit area (8.08 ton h^-1) due to its early tasseling (55.2 days) as well. Its superiority was in the weight of ears (180.2 gm).The interaction between genotypes and planting dates was significant for most of the traits. In conclusion, the hybrid (1×3) ×2 outperformed the other hybrids and was classified as superior in most traits, achieving the highest yield and not differing significantly from the triple hybrids (3×4) ×2 and  (3×5) ×2, due to the inclusion of the superior inbred 3. We propose studying these three-way hybrids under different planting dates in the spring season to assess their environmental adaptability to the climate of Iraq, and testing them under stress conditions such as drought.