Selective herbicide are those which are applied to the mixed population and kill only target plants or weeds, while crops are no affected.
Eg. 2, 4 – D, EPTC, Butachlor, MCPA, Alachlor etc.
b.Non – selective herbicide:
Non – selective herbicide are those which are kill all the plants of all the species.
Eg. Paraquat, Diquat etc.
2)On the basis of mode of action:
a.Contact/ Non – systematic:
Contact herbicide kill only the part of the plant to which they are come in contact. The whole plant dies due to loss of functional integrity of the plant. For effective control of weed with contact herbicide a through coverage is essential.
Eg. Paraquat, Diquat etc.
Translocate are those herbicide which applied to the plant translocate throughout the plant body and kill them. Through coverage is not necessary for translocate herbicide.
Eg. 2, 4 – D, 2, 4, 5 – T and MCPA etc.
3)On the basis of place of application:
a.Foliage applied herbicide:
Foliage herbicides are those which are applied above ground parts of plants.
Eg. 2, 4 – D, Paraquat
b.Soil applied herbicide:
Soil applied herbicide are those which applied to the soil and kill the weeds as they emergence through the soil.
4)On The basis of time of application or crop situation:
a.Pre – planting herbicide:
Pre – planting herbicide are those which are applied before planting or sowing of the crops. It is grouped into –
i.Pre – plant post weed emergence: Pre – plant post weed emergence herbicide are those which are applied before planting on the standing crops.
ii.Pre – plant soil incorporated herbicide: Pre – plant soil incorporated herbicide aare applied before the planting of crop but incorporated in the soil during final land preparation.
b.Post – planting herbicide:
Post planting herbicide are those herbicide which are applied after planting of crops. It is divided into –
i.Pre – emergence: Which are applied after sowing but before emergence of seedlings.
Eg. Nitrophen, Butachlor.
ii.Post – emergence: Which are applied after emergence of seedling.
Eg. Propalin, Dicamba etc.
1.On the basis of origin/ source:
a.Inorganic herbicides: Inorganic herbicides are not contain carbon atoms in their molecule.
Eg. Arsenic acid, Sulphuric acid.
b.Organic herbicide: Organic herbicides contain carbon atoms in their molecule
In my opinion, agriculture is the key to advancing the economy. You can understand the fundamentals of agriculture by reading this site, which will improve your academic performance. To serve the country and become a skilled farmer, read carefully. We have a lot of responsibility, so we need to keep learning new things.