Testing Two Varieties of Maize (Zea mays L.) Under Surface and Conventional Farming Systems at Different Speeds, Based on Some Mechanization and Yield Indicators

The experiment was conducted in Al-Abbasi sub-district, Al-Hawija district, about 72.6 km from Kirkuk center (latitude N35.270768, longitude E43.630299) during the spring season of 2025. The study investigated the effect of three factors on maize (Zea mays L.) traits, including mechanization indicators, yield, and its components. The factors were: tillage system (no-tillage and conventional tillage), three forward speeds (6.42, 7.23, and 8.15 km·h⁻¹), and two maize varieties ( Toro and Royal). Twelve treatments were arranged in a randomized complete block design (RCBD) with a split-split plot arrangement and three replications. Duncan’s Multiple Range Test at 0.05 probability was used to compare means. Studied traits included: number of ears per plant, number of rows per ear, number of kernels per row, number of kernels per ear, 300-kernel weight, and emergence percentage. Results indicated that mechanization traits were significantly influenced by the first two factors, while other traits were affected by all factors. The interaction between conventional tillage and 8.15 km·h⁻¹ speed produced the highest significant values for field emergence percentage, number of rows per ear, 300-kernel weight, and ear weight. The speed of 8.15 km·h⁻¹ excelled in number of rows per ear, whereas 6.42 km·h⁻¹ resulted in the highest number of kernels per row. The Toro variety showed superior performance in most yield traits, except 300-kernel weight, which was higher in the Royal variety. Conventional tillage × Toro yielded the best values for ears per plant, kernels per row, and kernels per ear, while conventional tillage × Royal achieved the highest 300-kernel weight. No-tillage × Toro gave the highest number of rows per ear, and 6.42 km·h⁻¹ × Toro produced the best number of kernels per row and per ear.