Effect of the sowing geometry on wheat yield- A review

Weed infestation is a main cause of low productivity. In Pakistan, wheat yield decreased by 25% due to weeds infestation. Weeds are the most effective in reducing crop yield by competing for; water, nutrients and space. Weeds can be removed manually by hands or handy tools. Excessive amount of cheap manual man power is necessary for manual weeding. Biological control involves the use of insects or pathogens that reduced weeds infestation. However, chemical control involves the use of herbicides. Chemical weeding is the most extensive method has adverse effects on the environment enforcing farmers to adopt mechanical weed control methods. Mechanical control method consists of destroying through physical disruption. Such methods includes; pulling, digging, ploughing and mowing agricultural lands. Weed infestation have comparatively more adverse effect on yield as compared to irrigated areas. In rainfed areas irrigation system is not available, rain is only a natural source of water, which hardly fulfills the crop water requirements, beside the crop requirements weeds infestation additionally compete with the wheat for water and nutrient uptake that is the most important factor of low productivity. To decrease weeds infestation and to increase wheat growth inter row spacing plays an important role. In the present work we highlight the potential impacts of inter-row spacing on growth performance of wheat. Additionally the review also highlights some of the responses and measures adopted globally in order to combat the issue of weed infestation and its impacts on wheat production.