Integrated weed management (IWM) combines various methods to control weeds that negatively impact crops, such as grazing, herbicides, and biological control. Weeds compete with crops for resources and can significantly reduce crop yield and quality, making effective management crucial. Strategies include indirect methods like preventive and cultural practices, and direct methods like manual, mechanical, biological, and chemical controls.

1. INTEGRATED WEED
MANAGEMENT (IWM)
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Department of Agronomy
Bahauddin Zakariya University Multan

2. Introduction:
 What is a weed?
There are numerous definitions of a weed, including:
 a plant out of place and not intentionally sown
 a plant growing where it is not wanted
 a plant whose virtues have not yet been
discovered. (R.W.Emerson)
 plants that are competitive, persistent, pernicious,
and interfere negatively with human activity (Ross,
et. al.)
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3. Integrated Weed Management
Definition:
“An integrated weed management approach to land
management combines the use of complementary weed
control methods such as grazing, herbicide application,
land fallowing, and biological control.”
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4. Importance of Weeds Management
Those plants that interfere with human activity in crop and non-crop areas are considered
weeds. Weeds compete with crops for soil nutrients, water and light; they host insects and
plant pathogens harmful to crop plants, and their root exudates and/or leaf leachates may be
toxic to crop plants. Weeds also hinder crop harvest and increase the costs of such operations.
In addition, at harvest, weed seeds often contaminate the crop produce. Thus, the presence of
weeds in crop areas reduces the efficiency of inputs such as fertilizer and irrigation water,
enhances the density of other pest organisms, and finally severely reduces crop yield and
quality.
(Labrada and Parker 1999)
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5. Crop-weed Compitition
Crop Weeds
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Light
Water
Nutrients
Space

6. Integrated weed management
A) Indirect Methods
1) Preventive Methods
2) Cultural Methods and ecological Methods
B) Direct Methods
1) Manual Methods
2) Mechanical Methods
3) Biological control
4) Chemical control
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7. A) Indirect Methods
1) Preventive Methods:
 Use of clean seed
 Use of clean farm equipments
 Clean leaves, watercourses and irrigation canals
 Control grazing of livestock
 Ensure that farmyard manure and other soil materials are free of weed
 Prevent the formation of weed seeds or vegetative progules
 Act collectively against wind-borne weeds/weed seeds
 Adopt specific measures when harvesting weed-infested crops
 Legislation
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9. 2) Cultural Methods:
I. Tillage
I. Preparatory Tillage
II. Seed Preparation
III. Cultivation/harrowing/hoeing/earthing up
II. Rotation
III. Allelopathy
IV. Flooding and drainage
V. Methods of Planting
VI. Planting density
VII. Variety
VIII. Mulching
IX. Planting time
X. Farm Management Practices
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10. B) Direct Methods
1) Manual Methods
Manual methods includes pulling of
weeds by hand, cutting them with a sickle,
hoeing with hand tools and burying the
weeds under soil or water with the feet.
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11. 2) Mechanical Methods
These methods involve the use of
implements such as bar harrows, weeders,
and cultivators driven by an animal or
engine.
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12. 3) Biological control
Biological weed control involves using living
organisms, such as insects, nematodes,
bacteria, or fungi, to reduce weed
populations. In nature, plants are controlled
biologically by naturally occurring organisms.
Plants become pests - and are labeled
"weeds" - when they run rampant because
their natural enemies become ineffective or
are nonexistent.
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13. Examples of Biological weeds control
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14. Examples of Biological weeds control
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15. Examples of Biological weeds control
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16. 4) Chemical control
Definition:
Herbicides are chemicals that kill or alter the
normal growth of weeds.
They can be divided into two main groups:
selective and nonselective.
Selective herbicides are those that control
the target weed(s) without damaging desirable
turfgrass species.
Nonselective herbicides kill all vegetation
(including turfgrasses) and are used in lawn
renovation or on weeds not controlled by selective
herbicides.
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17. Different ways of Chemical Control
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18. THANK YOU !!!
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