فهرست نشریات علمی دسترسی آزاد ایران

Objective: This study investigated the effects of row spacing, planting pattern, and weed control methods on maize grain yield, weed control, antioxidant defense system, and osmolyte accumulation.Methods: To conduct the experiment, the maize cultivar TWC647 was planted in the row spacings of 75 cm and 65 cm, using two planting patterns, conventional single-row (CSR) and zigzag double-row (ZDR). Also, five different weed control methods were implemented, including a weedy check throughout the growing season, Trifolium alexandrinum L., Secale cereale L., Vicia villosa L., and the herbicide MaisTer Power OD® 42.5% (containing foramsulfuron and idosulfuron). Then, the protein content, H2O2, total phenols, total soluble proteins, proline, superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and malondialdehyde (MDA), were measured.Results: The biomass of cover crops was significantly affected by row spacing, planting pattern, cover crop, and their two-way interactions. The highest cover crop biomass was obtained for the 75 cm row spacing with the CSR planting pattern. The rye cover crop showed the highest biomass in both row spacing and the CSR planting pattern. The distribution of grass weed species was relatively even throughout the experimental site. The lowest weed biomass was obtained in rye and vetch with the 65 cm row spacing and also under both CSR and ZDR planting patterns. Maize grain yield was significantly affected by the row spacing × cover crop interaction, with maize alongside the rye cover crop producing the highest grain yield per hectare in the 65-cm row spacing, significantly higher than in the 75-cm row spacing. MDA was higher at the 65 cm row spacing and under CSR planting pattern than at the 75 cm row spacing and ZDR planting pattern. The lowest and the highest MDA among the weed-control methods were observed for the rye cover crop and the herbicide MaisTer. H2O2 was also higher in the 65 cm row spacing. The highest H2O2 content of maize leaves was obtained for the herbicide MaisTer under CSR. Proline, total proteins, and total phenols were also greater at the 65 cm row spacing.Conclusion: The narrow row spacing (65 cm) with rye inter-row cover crop reduced weed biomass compared to wider row spacing (75 cm). The 65 cm row spacing also resulted in higher grain yield of maize when the rye cover crop was planted among the maize rows. The 65 cm row spacing also exhibited higher total proteins, total phenols, proline, MDA, and H2O2 content. However, the rye cover crop decreased H2O2 and MDA compared to the herbicide and weedy check.