Effect of planting dates and DSPER size spraying on maize growth

Aiming to study the effect of planting dates and spraying with the compound DSPER Size on the growth of (Zea mays L.), a factorial experiment was conducted using a randomized complete block design (RCBD) with split-plot design and three replications. The experiment was carried out in one of the agricultural fields designated for the Field Crops Department, College of Agriculture, University of Kerbala, at the Ibn Al-Bitar Vocational School in the Al-Husseiniya region during the summer season of 2024. The experiment included two factors Main plots planting dates (July 10, July 20, July 30, and August 9) and Subplots concentrations of the DSPER Size compound (0, 1.0, 2.0, 3.0, and 4.0) g l-1. The results showed that the third planting date (July 30) outperformed in some of the studied traits, recording the highest mean plant height (223.71 cm) and stem diameter (29.781 mm). Meanwhile, the fourth planting date excelled in leaf area, with a mean of (6853.6 cm²), and chlorophyll content, of (60.581 SPAD). The treatment with the compound concentration of 3 g L⁻¹ significantly outperformed in giving the highest means for all traits plant height (213.25 cm), stem diameter (29.810 mm), number of leaves (13.240 leaf plant-1), leaf area (6697.4 cm²), and chlorophyll content (61.230 SPAD).The results of the study also showed the superiority of the interaction treatment between the third planting date (July 30) and the concentration of 3 g L⁻¹, which resulted in the highest plant height of (225.23 cm) and the number of leaves reaching (14.630 leaf plant-1).