Comparative study of effect of Lantana camara extract of different parts on seed germination of Parthenium hysterophorus L.

Weeds pour serious problem to farmers throughout the world reducing yield and quality of crops. Parthenium hysterophorus L. also known as American weed or carrot grass. Parthenium hysterophorus (Asteraceae), a native of West Indies and Central and North America. It is an exotic weed and was introduced in India along with food grain under PL 480 scheme. The weed was reported for the first time in India 1956 (Rao, 1956). Parthenium hysterophorus is a problematic weed to human and floral diversity. It is commonly spread road sides, waste lands, marshy lands and fertile lands. A plant can produce more than 20,000 seeds which require bare soil to germinate without any dormancy. Parthenium is a allergic plant and Its pollen can cause allergic reactions such as respiratory problems, weight loss, swelling, contact dermatitis etc. Parthenium produce several allelochemicals such as alkaloids, parthenin, kaempferol, P-coumari acid, caffic acid (Towers et al., 1977). Parthenium inhibits the seed germination and growth of other plants. Lantana camara is one of the ten worst weeds of the world and is serious weed in 14 crops in 47 countries. However, allelopathic effects on crops have been studied least (Narwal, 1994). Various allelochemicals present in different parts of Lantana camara and has allelopathic effect against agronomic crops and it is one most toxic weeds in the world (Holm and Herberger, 1969). The leaf extract of Lantana camara produced inhibitory effect on growth of Parthenium (Ravindra et al., 2008). Allelopathic effect induced by Lantana camara inhibits growth of other vegetation as well as seed germination. Because Parthenium is a toxic weed has become a serious threat to plant biodiversity and environmental safety and its control at the first stage (seed germination) is very essential. Allelochemicals of Lantana camara were used to inhibit seed germination of Parthenium which is a ecofriendly method. Present paper deals the effect of various concentrations of stem, leaf, flower and fruit extract of Lantana camara on germination of seeds of Parthenium.