(a) What are weeds ? Name any one weed found in a crop field.

(b) How do weeds affect the growth of crops ?

a)

Weeds are the undesirable plants that grow in fields along with the crops. They damage the crops by using the same nutrients that crop plants use, often in very similar proportions. They also compete with the crops for resources such as water, sunshine and space. Ultimately these affect the growth of crops and their productivity.

Xanthium is the weed found in a crop field.
b)

Weeds are the unwanted plants that compete with the crop plants for nutrition and various other factors. Thus, they damage crops by affecting their growth.

Weeds compete with the main crop plant for air, water ,sunlight and nutrients in the soil making them deficient for the main crop. Also, they are not of use to humans. Thus they affect the growth of the plant and their removal is necessary.

Some measures to control weeds :

1. Manual removal .
2. Spraying weedicides.
3. proper soil and seed preparation.
4. timely sowing of crops , intercropping and crop rotation.
5. use of resistance variety crops , which resist the attack of pathogens.
6. summer ploughing , which includes deep ploughing to destroy weeds and plants