Integrated Weed Management
Integrated Weed Management is a system which brings together all feasible methods of weed control harmonizing them into a single unified and co-ordinated system designed to maintain weeds at levels below those at which they would not cause economic loss.
The fundamental principle is to deprive the weeds of the possibilities of developing their strong points.
It includes three broad components: (1) cultural and mechanical, (2) biological, and (3) chemical.
- Ploughing once before onset of monsoon and two times during later period, will eliminate weeds and depletes weed seed bank in the soil.
- In the main field, before planting of rice either dry seeded or transplanted, ploughing the field once, and puddling twice, and ponding of water for one to two weeds; will not only effectively kill the weeds but also, release the soil nutrients, for use by rice due to creation of anaerobic conditions,
- After planting of rice, hand weeding at 20,40 and 60 days, will usually control most of weeds and this is most eco-friendly and economical method of weed management.
- Application of mono herbicides like cheroacetamides, as pre-emergence to weeds at 0-7 days after planting w ill effectively reduce the grassy weed population. In areas when broad leaved weeds emerge, during later crop growth period, sulfonil-urea herbicides can be used at 15-25 DAT as post-emergence application. In case of mixed population of grassy and BLWs appear, during early or mid – season, combination herbicides almix + butachlor, bensulfuron – methyl + pretilachlor or triasulfuron+pretlachlor and anilophos+ethoxysulfuron can be applied at 0-5 or 5-12 DAT for broad spectrum weed control.
- Sequential application of herbicides Grassy weed herbicides at 3-5 DAT and application of sulfonil urea herbicides or BLW killers, at 20-25 DAT, will help in controlling weeds, under such situations.
- In direct seeded rice under puddled conditions, the safener + herbicide compounds can be profitably employed for controlling weeds, without causing injury to rice crop.
- In environmentally sensitive rice growing areas, the non-chemical methods, like adoption of suitable farming systems and crop rotations, also merits serious consideration,. Additionally, the farming systems involving cattle and goat rearing, duckery, piggery, poultry , fish culture in conjunction with rice cultivation will help in removing the weeds during fallows, or during crop season; also helps in supplementing the farm income.