· Weeds are unwanted and undesirable plants which interfere with the utilization of land and water resources and
thus it adversely affects the human welfare.
· It also referred to as plants out of place.
· A weed is plant growing where and when it is not desired
· A plant that is extremely noxious, useless, unwanted or poisonous
· There are over 30,000 species of weed around the world
· Of which about 18,000 cause serious losses to crop
· The extent losses due to weeds depends on
1. Intensity of infection
2. Time of occurrence
· 3.Type of weeds
Weeds induce the fire accidence in electricity department
Loss of quality of agricultural products
Cause health problems to human beings. Eg. Parthenium hysterorus
Reduce the land value
Some weeds are poisonous to livestock
Weeds( thorny) reduces the efficiency of human beings and affect
movement of workers.
Method of Weed Control
Weed control methods are broadly grouped into
CHEMICAL WEED CONTROL
A herbicide is a chemical used to kills some target plants, especially the weeds.
Chemical weed control
The chemical weed control includes the use of herbicides for controlling weeds.
Advantages of chemical weed control
Herbicides can control weeds even before they emerge form the soil
Large area can be covered in a short time
Use of herbicides is possible in areas - labour is scarce/costly
Root system is not damaged as in the case of mechanical weed control
But herbicides action the entire plant system in controlling the weeds.