What is Weed?

Definition of Weeds:

A Great Britain farmer Jethro Tull was the First person who have defined weed in 1731.
A weed is plant growing where it is not desired.
A weed is a plant growing out of its place.
Any plant not sown in the field by the farmer is out of place and is called weed.
Any plant or vegetation excluding fungi interfering with the objectives or requirement of people called weed.

As per the meaning of first two definitions, a plant could be undesirable at one place and desirable at other place. E..g Hariali, foxtail and goose grass are valuable plant in pasture but in crop field these are well known trouble some weeds. Meaning of another two definitions is if farmer has sown a sorghum crop in the field then the plants/ vegetation other than sorghum are considered as weed.

Weed Management and Its Important

Weed Management:

It is the process of keeping or minimizing the weed population and their growth below the level of economic injury to the crop with minimum environment pollution. Weeds can be managed by adopting any suitable method of weed control and if needed by combining two or more methods of weed control.

Importance of Weed Management:

The total annual loss of agricultural produce various due various parts in India is as below

1) Weeds: 45%
2) Insects: 30%
3) Diseases: 20% 
4) Other pests (Rats, wild animals)

A recent estimate shows that weeds cause annual loss of Rs. 1980 crores to Indian Agricultural which is more than combined losses caused by insects, pests and disease. Weed pest is the enemy No.1 to the crops. Weeds compete with crop plants for plant for plant nutrients, soil moisture, space and sunlight. Weeds are hardy ad vigorous in growth habit.