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How 2,4,D Kills Broadleaf Plants

Written by Stephanie on March 22nd, 2011
This is the time of year when many people are looking for weed control.  Broadleaf weeds are one of the major groups of weeds that cause problems in lawn — think dandelions, for example.  These weeds are so pervasive that there are products that combine broadleaf weed killer with fertilizer so that a homeowner can kill their weeds and make their grass grow at the same time.  Most of these products contain some form of 2,4,D.
How exactly a particular herbicide works can be hard to distinguish because it is hard to actually watch the events unfold under a microscope.  However, it is widely believed that 2,4,D interferes with protein synthesis in ways that cause the plant cells to undergo rapid, uncontrolled cell division and elongation.  In other words, the plants grow themselves to death.
2,4,D is typically sprayed on a plant or placed around it in granular form, then watered in.  The roots and leaves of the plant readily absorb the chemical and transfer it throughout the plant’s tissue.  The uncontrolled division and elongation of the cells begins immediately and rapidly kills the plant.
This is wonderful news if you are trying to kill the plant.  It is not so good if you put it on something susceptible to 2,4,D expecting to kill the weeds but not the lawn.  However, that happens every spring when individuals with Saint Augustine lawns use some sort of weed and fertilizer product.  It kills the weeds, but it also kills the lawn.
Saint Augustine happens to be a broad leaf plant rather than a true grass, so will die if treated with 2,4,D.  In fact, if you have broadleaf weeds such as dandelions in your lawn, about the only thing you can do is dig them out. Any chemical that will kill them will also kill your lawn.
Herbicides can certainly make our lives easier.  They are responsible for a relatively small number of farmers being able to grow enough food to feed all of us.  However, we must take time to understand their mode of action and where they can and cannot be used if we want to use them safely.

This is the time of year when many people are looking for weed control.  Broadleaf weeds are one of the major groups of weeds that cause problems in lawn — think dandelions, for example.  These weeds are so pervasive that there are products that combine broadleaf weed killer with fertilizer so that a homeowner can kill their weeds and make their grass grow at the same time.  Most of these products contain some form of 2,4,D.

How exactly a particular herbicide works can be hard to distinguish because it is hard to actually watch the events unfold under a microscope.  However, it is widely believed that 2,4,D interferes with protein synthesis in ways that cause the plant cells to undergo rapid, uncontrolled cell division and elongation.  In other words, the plants grow themselves to death.

2,4,D is typically sprayed on a plant or placed around it in granular form, then watered in.  The roots and leaves of the plant readily absorb the chemical and transfer it throughout the plant’s tissue.  The uncontrolled division and elongation of the cells begins immediately and rapidly kills the plant.

This is wonderful news if you are trying to kill the plant.  It is not so good if you put it on something susceptible to 2,4,D expecting to kill the weeds but not the lawn.  However, that happens every spring when individuals with Saint Augustine lawns use some sort of weed and fertilizer product.  It kills the weeds, but it also kills the lawn.

Saint Augustine happens to be a broad leaf plant rather than a true grass, so will die if treated with 2,4,D.  In fact, if you have broadleaf weeds such as dandelions in your lawn, about the only thing you can do is dig them out. Any chemical that will kill them will also kill your lawn.

Herbicides can certainly make our lives easier.  They are responsible for a relatively small number of farmers being able to grow enough food to feed all of us.  However, we must take time to understand their mode of action and where they can and cannot be used if we want to use them safely.

 



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