HOW TO PART WITH PARTHENIUM

While I go for my early walk, I notice many kinds of plants, big and
small all along the way.

One of the small categories, about 50 to 100 cm tall green plants with
full of tiny white flowers do not escape my eyes.

They are in thousands growing happily all along the road and also in
plots where no house is constructed so far.

Residential colonies are invaded by these plants which are called
parthenium causing diseases like dermatitis and asthma.

Along with this, many other unwanted plants grouped as weeds also
grow, flower and die.

They are the annual plants botanically called Parthenium hysterophorus
and popularly known as Congress Grass or Carrot Weed.

It belongs to the botanical family, Asteracae.

These plants are very difficult to eradicate.

It appears that Parthenium is not native to India, but it came with
the imported wheat as a mixture, when the US sent wheat to India under
PL 480 (Public Law 480 passed in 1954 to give food grains to
developing countries) in 1956.

However this concept was contradicted by some as not the real story
because Parthenium was present in India even in 1951 itself.

The tiny seeds spread throughout the country.

Today we do not have a place in India free from this noxious unwanted
notorious weed.

In general, weeds grow widely in waste lands, fields and field bunds.

Controlling this weed was a stupendous task for weed scientists.

So far no single method appears to be satisfactory.

Since the regeneration capacity of this weed is very high, even the
mechanical eradication like cutting or slashing did not work.

Removal by hand or hoe at the pre-flowering stage is one of the
physical methods of eradication recommended.

But there are other methods too.

Weed killing chemicals are sprayed on the land to kill the weed seeds
or on the land to kill the weed seeds or on the post-emergence stage
of the weeds.

One of the potent chemical used was the sodium salt of 2,
4-dichlorophenoxy acetic acid popularly called 2, 4 â€" D which acts as
a plant hormone at homeopathic dose whereas at high concentration it
kills plants.

These chemicals are grouped as herbicides or weedicides.

Large scale usage of herbicides are followed at the US, Australia and
many other advance countries but only limited quantity is being used
in developing countries like India.

These herbicides are specific for certain plant species.

For example, dicot plants are generally susceptible to all herbicides
whereas the monocots â€" the grass family can not be eradicated by most
of them.

Fortunately Parthenium is a dicot plant amenable for a variety of
herbicides.

In fact, research to find out suitable chemicals for eradicating weeds
in cultivated fields as well as in waste land is being extensively
carried out in various agricultural universities and research institutes.

Even biological control measures and biotechnology techniques are
attempted to eradicate Parthenium.

Parthenium, the most unwanted one is around us everywhere.

To control this weed, awareness camps are conducted regularly in every
colony as it has been done in villages for the farmers.

Instructions are given to the citizens for effectively controlling
Parthenium.

I used to watch carefully the growth behaviour of this weed.

At the onset of South West monsoon, the plants emerge from the soil in
rosette form by spreading its leaves close to the ground without an
elongated stem.

Only with the shower of rain, these plants look dark green as if we
have applied good amount of nitrogenous fertilizer.

I do not know how they get such green foliage?

May be they mine the nutrients available in the waste land.

A month afterwards, I used to observe them to put forth elongated stem
which grow to the size of about a metre with good number of branches
with hundreds of tiny white flower buds.

This process is technically called as bolting.

Once the plants reach such a stage, the pollen from the flowers fly in
the air and animals and humans happen to inhale them and end up in
irritation of body and develop allergy symptoms.

I tried to pull out some of these plants which came up in front of my
house.

Fortunately I did not get the allergy, when I enquired with the weed
specialists, they told me that it will affect only some susceptible
people.

I was happy that Parthenium is afraid of me.

Once the Parthenium blooms, the seeds â€" thousands of them are carried
by wind and spread all around the place.

The seeds settle on the dry soil and stay there till another rain comes.

They remain dormant for a long period of time in the dry soil.

Scientists tried to extract the leaves of this noxious weed and used
for controlling some insects affecting crop plants.

The results were not encouraging.

Therefore even today this weed, remains as a menace for human beings.

In residential areas, to control this and other weeds, the only way
comes to my mind is to construct houses as soon as possible without
leaving the plots vacant.

No other method is in sight for the time being to get rid of
Parthenium around the residential colony.

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