Mention any one difference in external features of weeds and wheat plant. How do weeds affect crop yield ? Describe how weeds are removed.
Wheat plant is a monocot, with hollow stem, sheathing leaf base and parallel venation. The inflorescence is spike.
If the weed is a dicot like Argemone maxicana, the leaves will have reticulate venation and the leaves will have spiny margin.
Weeds affect crop yield in an adverse manner. They compete with the crop for space, sunlight, nutrients, water and thus affect the growth of crop in an adverse manner. Since, crops do not get enough space, nutrients; water due to weeds their growth is retarded and thus yields is also reduced.
Weeds are removed by the following ways:
$$\cdot$$ Weeds can be removed using herbicides.
$$\cdot$$ By mechanical method of removing weeds manually.
$$\cdot$$ By adopting crop rotation and inter cropping method.