Study of Different Rates of Application of Mixture of Amidosulfuron and Iodosulfuron-Methyl-Sodium on Broadleaf Weed Infestation and Grain Yield of Soft Wheat

Aims: A soft wheat weed control trial was conducted in order to investigate the effect of mixture of Amidosulfuron and Iodosulfuron-methyl-sodium on controlling broadleaf weeds infestation in a soft wheat crop.

Study Design: The experimental design was a random block with three replications. Each block contained 4 elementary plots, 3 plots of which are treated with three doses of mixture of Amidosulfuron and Iodosulfuron-Methyl-Sodium and one untreated control plot.

Place and Duration of Study: Field experiments in Ouazzane region of Morocco. Laboratory measurements were carried out at weed research laboratory of INRA-CRRA Tangier. Morocco, between December 2016 and July 2017.

Methodology: Treatments was applied at weed seedling stage. Three doses of mixture of Amidosulfuron and Iodosulfuron-methyl-sodium were applied. Observations were made 14, 28 and 56 days after application of herbicides (DAT). Observations concerned selectivity of applied treatments, percentage of weed density reduction, biomass reduction and soft wheat grain yield.

Results: Results showed that treatments with mixture of 15 g/ha Amidosulfuron + 3.75 g/ha Iodosulfuron-methyl-sodium and 22.5 g/ha Amidosulfuron + 5.63 g/ha Iodosulfuron-methyl-sodium gave the best control of broadleaf weeds infestations and provided the best wheat grain yield. No phytotoxic symptoms were observed on soft wheat crop. Treatment with mixture of (15g/ha Amidosulfuron+ 3.75 g/ha Iodosulfuron-methyl-sodium) recorded 95.7±1.3%, and 98.5±0.5% respectively on weed density reduction, and weed dry biomass reduction. Treatment with mixture of (22.5 g/ha Amidosulfuron + 5.63 g/ha Iodosulfuron-methyl-sodium) recorded 98.5±0.5% and 98.8±0.3% respectively on weed density reduction and weed dry biomass reduction. Treatment with mixture of (7.5 g/ha Amidosulfuron + 1.88 g/ha Iodosulfuron-methyl-sodium) recorded the lowest efficacies 60.7±10.2% and 70.2±3.3% respectively on weed density reduction and weed dry biomass reduction. Plots treated with mixture of (15 g/ha Amidosulfuron + 3.75 g/ha Iodosulfuron-methyl-sodium) and (22.5 g/ha Amidosulfuron+ 5.63 g/ha Iodosulfuron-methyl-sodium) recorded the highest yields of 3.65±0.1 and 3.46±0.3 tons/ha respectively an increase exceeding 74% over the control.

Conclusion: Mixture of (15 g/ha Amidosulfuron+ 3.75 g/ha Iodosulfuron-methyl-sodium) and (22.5 g/ha Amidosulfuron+ 5.63 g/ha Iodosulfuron-methyl-sodium) gave the best control of weed infestation in soft wheat and recorded the best grain yield. Therefore, mixture of (15 g/ha Amidosulfuron+ 3.75 g/ha Iodosulfuron-methyl-sodium) can be recommended in similar weed infestation in soft weed crop.