Weed management‎ > ‎

Preventive

Preventive methods

Preventive measures are those taken to avoid the introduction or spread of specific weed species in an area. It is easier to check the entry of weeds rather than removing them when they are already established. 

Ways of avoiding introduction of weeds in an area:

  • Use of good quality seed – pure, clean and viable.
  • Field sanitation

Clean and healthy seed

By ensuring that the seed used is clean the direct introduction of weed seeds can be avoided to the field or seedling nursery. Good seed can increase yields by 5-15% or even more.

Pure, clean and viable seeds  Unclean seeds with lots of contaminants   Seeds with mixture of other varieties

Good quality seeds

  1. The seed is pure – there is only one variety; not a mix;
  2. The seed is clean – does not contain weed seeds, stones or litter, and the grains are not discolored by disease; and
  3. The seeds are viable – they have high germination and the seedlings are vigorous.

Variety selection

Cultivars may differ in how competitive they are against weeds. Cultivars with greater seedling vigor, greater leaf area development, greater early height growth rates, and/or greater tillering ability are probably more competitive against many weeds.

Field sanitation

Clean bunds and canals

By keeping surrounding areas clean – especially waterways and bunds, the number of seeds being introduced into the field while irrigating can be reduced.

 

Cleaning bunds


Nursery management

As for good seed, a clean nursery with healthy seedlings avoids the direct introduction of weeds into the field fromt he nursery. Further, vigorous and healthy seedlings are better able to compete with weeds.

Nursery management

Clean equipment


Reduce the spread of weeds between fields by making sure equipment (e.g., powertillers, tractor wheels, combine harvesters, etc.) is not contaminated.
Clean equipment

Fallow management

Fallow management is an important option for reducing weed burdens by changing factors such as the aeration of the system - e.g., flooded to aerobic - and/or by preventing the production of seeds by weeds during the fallow period. Changing system aeration tends to force major shifts in weed species from one season to the next. Such strong changes in weed flora helps prevent the build-up of any dominant weeds that are favored by a particular set of growing conditions. Weed burdens can be reduced during fallow plowing, by not allowing weeds from setting seeds, and/or by burning crop residue. Burning, although not recommended because of its effects on reducing soil organic matter, can kill some surface seeds.

Fallow management