Concept of Prevention, Control and Eradication of weed.
Preventive measures/methods i) Pure and clean crop seeds and seed certification Always use pure, clean crop seeds, which do not add seeds of the existing or new weed species to the soil seed bank.
Similarly weeds not controlled by measures adopted should be removed from the field before they flowered vii) Sand, soil from an infested area should not be transported and used to a clean or cultivated area.
Weed Quarantine Law enforces isolation of an area where a serious weed has established and prevents further movement of the weed into a non-infested area.
No consignment of plants and plant products such as seeds of coarse cereals, pulses, oilseeds and fodder seeds and seeds/stock materials of fruit plants for propagation, if found infested or infected with a quarantine pest or contaminated with noxious weed seeds shall be permitted to be imported.
For example, in crop field, simazine (triazines) is used @ 1.0-2.0 kg/ha depending on soil type, soil pH and organic matter content, but the same as a soil sterilant, may be used as high as 40 kg/ha or more on pathways, roadsides, fence lines, industrial and factory premises and other non-crop areas.
They use to use “control” to mean control of weeds and definitely not to mean management of weeds.
Generally when a single method is exercised towards control of pests/weeds, it is more a control than management aspect of pests/weeds.
However, control still bears significance when many farmers use only herbicide to control weeds in crops.
Successful weed management requires proper plant identification, selection of effective management methods and monitoring the effects over time.

Planting peas and other legumes alongside cereal crops could help make farming greener, say ecologists.
Intercropping, as it’s known, could cut greenhouse gas emissions by reducing dependence on fertiliser, as well as boosting biodiversity, food security and opening up new markets for local food and drinks businesses.
This includes producing impressive crop yields without artificial nitrogen fertiliser — and inventing new ways of brewing and distilling with beans.
This is because peas and other legumes fix their own nitrogen.
And when grown with other crops such as barley, the peas supply the cereal’s nitrogen needs.
Farming also needs to diversify by growing a wider range of crops and develop new markets for local, sustainable food and drinks.
To find new markets for a larger legume crop, Dr Iannetta is also developing new ways of turning peas and beans into alcohol.
By turning pulse starch into fermentable sugars and alcohol from 40% beans intercropped with 60% barley — we have produced a beer using 40% less artificial fertiliser," says Dr Iannetta.
The final benefit of their fermentation process is that it also produces a high-protein by-product, which could be used to make fish farming more sustainable.
"These will have been produced using no human-made fertilisers, and give co-products that provide sustainable and profitable protein production for the food chain," he concludes.