Canola is a major oilseed crop of semiarid regions throughout the world. The productive performance of canola is influenced by different sowing methods and durations of weed–crop interference. Appropriate sowing methods combined with timely weed management during the early growth stages can significantly improve canola productivity. A field experiment was conducted to evaluate the effect of different sowing methods and durations of early-season weed interference on growth and yield components of canola crop at the Agronomy Research Area, Department of Agronomy, University of Agriculture, Faisalabad, during 2021–2022. The experiment consisted of three different sowing methods (flat, bed, and ridge) with five different weed–crop competition periods weed-free control, weedy up to 30, 40, and 50 days after sowing (DAS), and full-season weed competition. The design of the experiment was a randomized complete block design (RCBD) with a split-plot arrangement. Each treatment was replicated three times. The results showed that the lowest weed density and fresh and dry weights of weeds were observed in ridge sowing, followed by bed sowing, while the highest were recorded under the flat sowing method. Results for leaf area index, grain yield, biological yield, number of pods, number of grains/pod, harvest index, number of branches, plant height, 1,000-grain weight, and oil content showed the highest values in ridge sowing followed by bed sowing, while the lowest values were recorded under the flat sowing method. Among weed–crop competition periods, the weed-free control (season-long weed removal) produced the highest yield and quality parameters, whereas full-season weed competition resulted in the lowest crop performance. Yield and related traits progressively declined as the duration of weed competition increased from 30 days after sowing. In conclusion, the results showed that sowing method significantly influences canola yield and quality, and prolonged early-season weed interference substantially reduces crop productivity. Based on the results of this study, the ridge sowing method combined with weed-crop competition up to 30 DAS is recommended for canola cultivation.
Arshad et al. (Wed,) studied this question.