LPM 121: Fodder Production and Grassland Management (1+1)

METHODS OF WEED CONTROL

Preventive methods:

• Preventive weed control includes all measures taken to prevent or to arrest the introduction and spread of weeds. This method includes.
  • Use of clean seeds free from weed seed
  • By keeping bunds and irrigation channels clean
  • By using manures free from weeds (decomposed manure) and
  • By avoiding transport of soil from weed infested area.

Control Methods:

• Control methods can be classified into
  • Mechanical methods
  • Cultural Methods
  • Biological methods and
  • Chemical methods.
• Mechanical Methods:
  • Hand-pulling or Hand weeding, Hoeing, Tilling, Flooding, Burning and Mulching are examples of physical methods of weed control. These methods aim at destroying weeds by cutting and removal or by desiccation and exhaustion of weeds. The choice of each method depends on the location, extent and habitat of weeds. Hand-weeding is the most efficient method, but it is time consuming and costly.
  • Tillage is a practical method of controlling most of the annual weeds. Implements like plough, harrow and cultivators are used in this method.
• Cultural method:
  • Crop rotation:
    • Certain weeds are more common in some crops than in others. Rotation of crops is an efficient way of reducing weed growth. The crops that are selected in rotation will occupy the soil at different layers in each season and compete with weeds thus reducing weed growth.
  • Smothering crops:
    • Crops like sunflower, sorghum, sweet potato, fodder grasses are highly competitive and smother the weeds. Seeds with good germination will give the crop a vigorous and close stand and thus enable to reduce the growth of weeds.
• Biological method:
  • In biological control, a natural enemy of the plant is used which is harmless to desired plants.
  • Eg: Eradication of Opuntia weed by cochineal insect (Dactylopius tomentosus). Grass fish controls effectively submerged weeds like Hydrilla, Lemna, etc.
• Chemical method:
  • This method involves the use of a chemical for controlling weeds, chemicals which are used for controlling weeds are called Herbicides or Weedicides. The chemical method is easier, less time - consuming and less costlier.