Abstract
Background
Appropriate agronomic practices are required to ensure high and sustainable crop yields. Timely sowing of wheat at an optimum seeding rate plays an important role in weed management and obtaining higher crop yields.
Objective
This study assessed the impact of agronomic practices, i.e., herbicide application, sowing dates and seeding rates on weed management and productivity of wheat.
Methods
Experimental treatments comprised of three sowing dates (20 November, 5 December, and 30 December), three seeding rates (120, 160, and 200 kg ha -1 ) and application of herbicides (tribenuron methyl + clodinafop-propargyl).
Results
Sowing dates, seeding rates and herbicide application significantly affected dry weight of weeds, yield, and yield components of wheat. High seed rate and herbicide application in late-planted wheat (30 December) reduced the weed dry weight. Early-planted wheat (20 November) with 120 kg ha -1 seed rate resulted in a higher number of seeds/spike and 1,000-grain weight. Early-planted wheat (20 th November) with high seed rate resulted in a higher tiller population and total biomass, which ultimately increased the final grain yield and net profit.
Conclusions
Grass + broad leaf herbicide application on early-planted wheat with higher seed rates (160 and 200 kg ha -1 ) suppressed weed growth and helped to improve yield and yield-related attributes, and net returns of wheat in Iraqi Kurdistan region.
Grain yield; Herbicide; Planting density; Sowing dates; Weed dry weight