• Parthenium hysterophorus is a much-branched, short-lived (annual), upright (erect) herbaceous plant that forms a basal rosette of leaves during the early stage of growth. It usually grows 0.5-1.5 m tall, but can occasionally reach up to 2 m or more in height.
• It can germinate throughout the year
• Indian Name- Bhoothkeeda, Carrot weed, Chatakchandani, Coimbatore Chedi, Congress pacha, Gazar ghass and Osadi
• An annual herb, erect, up to 2 m in height; the stem is branched and covered with trichomes.
• Neotropical range; 30-90 cm growth in length
• Exotic situation; 2.5 metre growth in length
• Leaves are pale green, lobed, hairy, initially forming a basal rosette of strongly dissected leaves that are up to 30 cm in length, close to the soil, alternate, sessile, irregularly dissected and bipinnate, having small hairs on both the sides, resembling the leaves of carrot.
• Flowering occurs about a month after germination
• A large single plant produces up to 100,000 seeds in its lifecycle.
• More than 340 million seeds per ha can be present in the surface soil.
• Seeds do not have a dormancy period and are capable of germinating anytime when moisture is available.
• The highest germination rates are at temperatures ranging from 120C to 270C.
• Germination of parthenium seeds can occur between 8° C to 30° C the optimum temperature for germination being 22° C to 25° C.
• Persistence tests demonstrated that more than 70% of parthenium seeds buried at 5 cm below the soil surface survived for at least 2 years, whereas seeds on the soil surface did not survive for longer than 6 months. Seed viability for 20 years has also been reported.
• It prefers alkaline, clay loam to heavy black clay soils, but tolerates a wide variety of soil types.
• The weed grows well in areas where the annual rainfall is greater than 500 mm and falls dominantly in summer. It can grow up to an elevation of 2200 m above sea level.
• The allelopathic effect, coupled with the absence of natural enemies like insects and diseases, is responsible for its rapid spread in its introduced ranges.
• Growth inhibitors like lactones and phenols are released from this plant into the soil through leaching, exudation of roots and decay of residues. These growth inhibitors suppress the growth and yield of native plants.
Crops that are majorly affected by the growth of this Weed:
• Parthenium is reported to have insecticidal, nematocidal and herbicidal properties.
• The odour of the plant is apparently disagreeable to bees and they can be easily kept away by carrying a handful of Parthenium flower heads.
• A root decoction of the plant is used in treating amoebic dysentery.
• Sub-lethal doses of parthenin, a toxin recovered from Parthenium, exhibited antitumor activity in mice and the drug can either cure mice completely or increase their survival time after they had been injected with cancer cells.
• Parthenin is also found to be pharmacologically active against neuralgia and certain types of rheumatism.
• Can be used for mulching and for producing biogas, paper and compost.
• Parthenium weed extract has 95% repellency and oviposition deterrent properties against Callosobruchus chinensis in chick pea grains
• A larval mortality of greater than 50% has been recorded in 2% concentration for Helicoverpaarmigera (Sundararajan, 2002) and a significant decrease in life span and progeny production of the mustard aphid, Lipaphis erysimi, was reported (Sohal et al., 2002).
• Extract of parthenium weed was also found to significantly inhibit the growth of bacterial spot pathogen (Xanthomonas axonopodis pv. vesicatoria) infecting Capsicum frutescens (Sree and Sreeramulu, 2002).
• Foliar supplementation of the leaf water extract of parthenium weed on mulberry leaves stimulated silkworms to feed and utilize them more efficiently, resulting in vigorous growth of larvae, pupa cocoons and silk yield
• The dry leaf powder of P. hysterophorus causes wilting of Salvinia molesta, which is an invasive species in some water bodies
• The species can be used for bioremediation of lead and nickel contaminated soils and water sources.
• Parthenium argentatum can be used as a rubber substitute
• In man, the pollen grains, air borne pieces of dried plant materials and roots of parthenium can cause allergy-type responses like hay fever, photodermatitis, asthma, skin rashes, peeling skin, puffy eyes, excessive water loss, swelling and itching of mouth and nose, constant cough, running nose and eczema.
• In animals, the plant can cause anorexia, pruritus, alopecia, dermatitis and diarrhea. Parthenium can taint sheep meat and make diary milk unpalatable due to its irritating odour.
• In India, an extensive outbreak of weed dermatitis caused by Parthenium allergy involving around 1,000 patients and including some deaths has been reported.
1) Mechanical and cultural:
• Manual uprooting of Parthenium before flowering and seed setting is the most effective method.
• In certain parts of India, crop rotation using marigold (Tagetes spp.) during rainy season, instead of the usual crop, is found effective in reducing parthenium infestation in cultivated areas.
2) Chemical control:
• The use of Glyphosate, Atrazine, and Metribuzin has been promising.
• In open wasteland, noncropped areas and along railway tracks and roadsides, the spraying of a solution of common salt (Sodium chloride) at 1520% concentration has been found effective.
• The timing of chemical control is critical. The plants should be treated before flowering and seed setting and when other plants, especially grass, are actively growing and can recolonize the infested area.
• The leaf-feeding beetle Zygogramma bicolorataand the stem-galling moth Epiblema strenuanaare widely used in several countries to manage Parthenium.
• Z. bicolorata is now widely used in India to control Parthenium.
• The moth significantly reduces flower and seed production of the weed, especially at a young age.
• Another on-going development in the biological control of Parthenium is the use of a rust fungus, Puccinia abrupta var. partheniicola. Uredospore suspensions from 3-week old pustules of the rust have been applied to the foliage of Parthenium and a consistent control effect has been achieved. This fungus is now being evaluated for development as a mycoherbicide.
• Parthenium offers a big challenge to all attempts of control because of its high regeneration capacity, production of huge amount of seeds, high seed germinability and extreme adaptability to a wide range of ecosystems.
• The large-scale utilization of Parthenium may be one of the effective methods to make this weed useful. Parthenium has been well documented for its insecticidal, nematicidal and herbicidal properties.
• We at “Azeedo” are trying to develop a product that will be herbal and eco-friendly. The resource plant will be Parthenium weed. This will help the farmers to protect their crops with an affordable and eco-friendly bio-pesticide. Our product will help farmers to protect the post-harvest crop loss. Our product can also mimic the activity of a pesticide, insecticides and fungicides therefore a farmer buys one product but gets the benefit of multiple product at the same time.