Herbicide resistance is the inherited ability of an individual plant to survive a herbicide application that would kill a normal population of the same species. Due to more use of chemical herbicide , weed become resistant to particular herbicide then a normal recommend dose can not kill that weed.

1. Herbicide resistance
Submitted to:-
(A. P) Mr . Bishal kr Mishra
Submitted by :-
Dharmendra kr.
Bsc. Agri. 6th sem

2. Contents
1. What is herbicide resistance
(definition)
2. Area of high risk
3. Favorable cconditions.
4. Resistance mechanism.
5. Types of resistance.
6. Management.
7. stress weed and Super weed.

3. what is herbicide resistance
Herbicide resistance can be defined as the acquired ability of
a weed population to survive a herbicide application that
previously was known to control the population.

4. Area of high risk
• No physical or mechanical methods
use.
• only depending on chemical method.
• Repeated use of single type of
herbicide.
• Repeated use of same mode of action
herbicide.
• only one type of crop rotation.
• Heavy infestation of weed
• poor weed control.
In indogangetic plan Phalaris minor found resistance to
Isopruton

5. Favorable
conditions
1. Weed factor
• initial population of resistance weed.
• Prolific seed production.
• Quick germination.
• Fast dispersion.
• Hypersensitivity to herbicide
2. Herbicide factors
• Repeated use of similar herbicide
• Repeated use of similar mode of action.
• More residual effect.
• Specific mode of action

6. Resistance development

7. Resistance mechanism
1. Site of action resistance
• Alter the the site of action. ie. change the enzyme binding
site so herbicide become non effective.
• it is due to change in gene.
2. Excess production of enzymes/ site of
action
3.Exclusinory
ie. no herbicide molecules reach to site ofaction

8. Types of resistance
1. Single resistance
2. cross resistance
3. multiple resistance
4. Negative cross or collateral
resistance.
5. Reverse resisrance
6. Compound or co
resisistance

9. Management
• Check favorable and high risk
conditions.
• No totaly depend on chemicals.
• Use of intigrated weed
management.

10. Stress weed
Definition
Weed developed or grow in stress area or condition with
development of special mechanism for that condition which
support to grow and survive.
Stress
• abiotic (High temp.
low moisture)
• biotic ( pest and
diseas)
Char..
• special mechanism to survive.
• Hardy nature.
• No kill at normalrate of
herbicide
In stress weed absorption, translocation and mode of
action islow.l

11. example of stress and character of weed for survival against
herbicide
1. Low moisture condition weed.
• slow absorption and low respiration somolecule of herbicide does
notbreach to site of action .
2. Im dry conditions dust on leaf work as protection from
spray and reduce penitration
3.High temp. condition
weed chek transpiration with thickcuticle, waxy coating so no or
less herbiside penetrate.

12. Super weed
characters
• Highly resistant
• Difficult to manage
It is developed due to more use of
Herbicide tolrent crops such as
Glyphosate tolrent or Roundup reafy
crop.
Here in fig. Roundup ready crop is
growing and some weed also seen.we
use only glyphosate in this crop because
it is tolrent to glyphosate.
But some weed does not kill and develop
resistance

13. Pollen from resistance weed pollinate normal weed of same
species and develop a new highly resitant weed
×
More resistance
weed
Normal
weed
Resistance
weed

14. Thank you