Control Techniques of

Parthenium Hysterophorus (L.)

Parthenium Hysterophorus (L.)

• An annual exotic alien weed, currently considered one of the seven most dreaded weeds of the world.

• It is suspected to have sneaked into India along with wheat imported from the USA under PL-480 scheme some time in early fifties.

• It is known by several popular names such as gajar ghaas, congress grass, carrot weed, white cap or top etc. Some of the vernacular names by which Parthenium is called are chatak chandani,broom brush, asadi, gajari, phandriphuli, nakshatra gida, vayyari bhama and safed topi.

• The weed has high reproductive capacity, with light weight seeds which disseminate fast by wind,rain and traffic activity.

• Lack of seed dormancy also enables the weed to complete 3-4 life cycles in a year.

• Though no scientific estimates are available on the magnitude of its infestation in India, the weed is believed to have invaded millions of hectares of no-man’s land like uncultivated waste lands, road sides, railway tracks, parks, grasslands etc.

In Residential Areas

Impact on Crops

Due to the presence of chemicals like parthenin, hysterin, hymenin and ambrosin the weed exerts strong allelopathic effects on different crops grown in association.

• Poor germination and crop growth.

• Affects nodulation in legumes due to inhibition of activity of nitrogen fixing and nitrifying bacteria viz., Rhizobium, Actynomycetes,Azotobactor and Azospirillum.

• Parthenium produces enormous quantity of pollen (on an average 624 million/plant), which is carried away at least to short distance in clusters of 600-800 grains, and settles on the vegetative and floral parts, including stigmatic surface inhibiting fruit setting in crops like tomato, brinjal, beans, capsicum and maize.

• Reduction in yield up to 40% in agricultural crops and 90% in forage crops.

• The weed acts as an alternate host for many diseases caused by viruses in crop plants.

Alternate host for Mealy bug

Impact on Humans

• Direct contact with plant causes contact dermatitis. Adult males are more sensitive than females while children below twelve years age are unlikely to be affected.

• Even the presence of pollen in the air is allergic to some and may result in diseases like fever and asthma.

• It is a major cause of Allergic, Trinities Sinusitis, affecting about ten percent of the people who live near it (Tower & Subarao, 1992).

• It reduces yield of milk and weight of animals.

• It causes irritation to eyes.

Effect of Parthenium on human health

and livestock

Acute and chronic toxicity, ulcers both in the mouth and

digestive tract, oesophagus and abnormal folds, necrosis of

kidney and liver

Ulcerations in buffaloes, horses

donkeys, sheeps, and goats

Restlessness, natural falling of hairs from the dorsal region of

the neck and back, small boils and oozing of boils.

Hypersensitivity in rabbit

Inflamed udder and rashesFever in cows

Loss of scalp, body hair, ridging on nailsSevere dermatitis

General weakness, skin eruptionsFatigue

Sore throat, bubbles in the mouthAllergic papules

Cracks all over the soleAllergic reaction

Skin eruptions and itchingDermatitis

Skin eruptions and itchingEczematoid dermatitis

Chronic lichensified eczema of the exposed skin surfacesEczema

Seasonal eruption of the exposed skin surfaceContact dermatitis

REACTIONDISORDER

Toxicity of Parthenium hysterophorus L. to

cattle and buffaloes

Parthenium when fed to buffalo bull calves and cross bred bull calves resulted in acute toxicity leading to death. The former animals developed severe dermatitis. Autopsy revealed ulceration of alimentary tract. Extensive pathological changes were noticed in liver, kidney and skin.

Cellular and Molecular Life Sciences (CMLS) Volume 33, Number 10 / October,1977,Pages1358-1359

ManagementMechanical Control

• Uprooting the weed manually when the soil is wet and slashing with sword, collecting and burning the weed before flowering are some of the effective means of control.

• However, the manual removal is usually neither very effective nor economical, because of the rapid regrowth requiring repeated removals for season-long control.

• In gardens, tree plantation, roadsides, open wasteland, etc., the weed should be ploughed under before flowering.

THIS HAS PROVED FATAL TO THE PEOPLE INVOLVED AS IT CAUSES SEVERE SKIN DISEASES AND OTHER INFECTIONS ON CONTACT WITH THE WEED. MATURED SEEDS FALL ON THE GROUND AND MAY INCREASE INFESTATION.

BURNING TOO HAS PROVED INADEQUATE AS IT REQUIRED LARGE QUANTITY OF FUEL. MOREOVER, BURNING DESTROYS ALL PLANTS IN VICINITY.

Management

• Post-emergence application (before flowering) of Mera 71 @ 10 gms / L water.

• Parthenium is found mostly in no-man’s land use of chemicals in such areas need community efforts.

• There are many herbicides available in the market. Most of them in any case are effective only on two leaves plant.

Glycel take 10 / 15 days to decay the plant.

Chemical Control

Future strategies for Effective

Parthenium Management,

With the onset of monsoon, emerged seedlings

of sufficient height can be controlled by

spraying of glyphosate @ 1 per cent solution.

This application should be made at any cost

before blooming.

V. M. Bhan, Sushilkumar and M. S. Raghuwanshi, National Research Centre for Weed

Science, Adhartal, Jabalpur - 482 004, Madhya Pradesh, India

(Source : Bhan et. al. (1997) In : Proc. First International Conference on Parthenium

Management (Vol. I) : 90-95.

Management

Biological control

• Zygogramma bicolorata, a Mexican beetle (50-100 beetles/plant) has been found promising.

• Several insect biocontrol agents and fungal pathogens are currently in use in Australia against Parthenium.

• Management of Parthenium through biocontrol is considered as natural and self-sustaining.

• Mycoplasma-like organisms (MLO) could be utilised as they cause seed sterility.

THESE EXOTIC INSECTS ARE NOT EFFECTIVE SOME TIME BECAUSE OF THE INTERFERENCE OF WEATHER. LONG, DRY DAY PERIODS REDUCE THE GROWTH OF THE INCEST TO VERY LOW LEVELS.

Zygogramma bicolorata

Management

Cultural Control

• Growing competitive crops (fodder sorghum sunflower and maize) or

• self-perpetuating competitive plant species like Cassia sericea, C. tora, Tagetus erecta, and

• Abutilon indicum in non-crop areas is recommended for effective management of Parthenium.