Parthenium hysterophorus L. (family Asteraceae) is a poisonous, pernicious and aggressive weed. It is known to badly affect crop production, biodiversity, animal husbandry, human health and even ecosystem integrity (Rao, 1956; Kohli and Batish, 1994). It has some water soluble allelopathic chemicals such as phenolic acids and Parthenin—a sesquiterpene lactone of pseudoguanolide nature in various parts of the weed (Picman and Picman, 1984). It can be used as a soil supplement after removal of harmful allelochemicals. Adoption of vermicomposting technology constitutes an essential component of organic farming. Large number of weed plants that grow at an alarming rate and spread very fast in the cultivated lands, pastures, grasslands and forests are a good source of organic matter (Sharma et al., 2004). Vermicompost is a sustainable source of macro and micro nutrients and plant-growth regulating materials (humic acids and plant growth regulators like auxins, gibberellins and cytokinins) which are responsible for increased plant growth and yield of many crops (Krishnamoorthy and Vajrabhiah, 1986; Senesi et al. 1992; Atiyeh et al. 2000; Atiyeh et al. 2002). Effect of nanoparticles on crop plants is an emerging area of research that needs to be meticulously explored. In the recent past, engineered nanoparticles have received particular attention as potential candidates for increasing crop yield (Scrinis and Lyons, 2007; Barik et al. 2008; Arora et al. 2012). Some researchers reported the influences of chemically synthesized nano particles (gold, silver and iron) on crops by foliar spray. They concluded that nano particles treated crops showed a considerable increase in chlorophyll, protein, ascorbic acid, pod and grain weight (An et al. 2008; Roghayyeh et al. 2010; Nair et al. 2010). The effects of phyto mediated nanoparticles on crops have not been reported. In green chemistry method, the use of plants and microbes for the synthesis of metal oxide nanoparticles did attract the attention of researchers for having a rapid, in expensive, ecofriendly and a one-step method for the biosynthesis process (Kowshik et al., 2003).