International Research Journal of Environment Sciences________________________________ ISSN 2319–1414Vol. 3(5), 27-34, May (2014) Int. Res. J. Environment Sci. International Science Congress Association 27 Germination and Early Seedling Growth of Mustard and Wheat as Affected by Allelopathic Activity of Pinus Needle Extracts Baroniya S.S.1 and Baroniya M.B.2 Department of Botany, Govt. Shri Krishnaji Rao Pawar P. G. College, Dewas, MP, INDIA Department of Botany, Govt. College, Kannod, Dewas, MP, INDIAAvailable online at: www.isca.in, www.isca.me Received 8th March 2014, revised 22nd April 2014, accepted 20th May 2014 AbstractAn experiment has been conducted to assess the Allelopathic potential of Pinus needles on seed germination and early seedling growth of Wheat and Mustard. Phenomenon ofAllelopathy could be defined as involvement of phytochemicals in the growth and development of surrounding plants, which could be direct or indirect. Moreover the effects could be positive or negative. Plants release phyto-chemicals in the surrounding soil and environment. Allelochemicals are primarily phenolic compounds which are involved in causing number of problems, such as reduction in crop production due to changes in chemical as well as microbial composition of soil, changes in the structure of ecosystem and failure in regeneration of natural forests. In the present study we demonstrate the toxic effects allelochemicals from Pinus needles on Wheat and Mustard seeds. The main aim of this study is to draw attention to the allelopathic potential of phenolic compounds present in pine needles in as the main cause of reduction in crop production. Keywords: Allelopathy, crop production, mustard, phenolic compounds, wheat. Introduction Allelopathy is originate from the Greek words allelon and pathos which means to suffer of each other, and it could be understood as mutual suffering. Allelopathy could be explaind as useful and harmful effects of interaction between plants and microorganisms. Occurrence of weeds in natural and manmade ecosystems is a natural phenomenon. Weeds are reported to have negative impact on crop plants, they affect crop plants by sharing and utilizing the natural resources available in the soil environment. Weeds compete with agricultural plants for nutrients, water, light and space. Allelochemicals are mainly organic compounds released from leaves and other plant parts. Allelochemicals comprise of secondary metabolites and are predominantly found in perennial plants such as Pinus, these chemicals exert impact on other plants growing in their surrounding area and the phenomenon known as allelopathy. Few researchers consider allelopathy, as harmful interactions while, few of them consider allelopathy to both damaging and beneficial interactions between the plants. Reduction in germination and growth of agricultural crops has been acredited to phytotoxic chemicals released from the leaf litter and roots. Many species of weeds produce toxins that are inhibitory to other weeds and often to themselves. Himalayas are one of the hot spot of biodiversity. Chir (Pinus roxburghii) is one of the five indigenous species of pine extensively distributed in the outer ranges and principal valleys of Himalaya between 450–2300 m elevation, and from North-West of Afghanistan to the North-Eastern part of India in Arunachal Pradesh between 26°N–36°N latitude and 71°E–93°E longitude figure 1. Every year, the dried needles of Pine trees forms a dense carpet on the forest floor, which are gathered by the locals in large bundles to serve as bedding for their cattle, for the year round. Still a large quantity of these needles is left on the forest floor and with the rain water these needles are weathered and the lechates from them are mixed with the surrounding soil environment. Pinus needles are known to have terpenes in the oil which is reported to inhibit growth of fungi and bacteria. In this context, a study was conducted to reveal the potential effects of allelochemicals from Pinusneedles on seed germination and early seedling growth of wheat and mustard. Material and Methods The allelopathic potential of Pinus roxburghii needles was studied in laboratory conditions. The needles Pinus roxburghiiwere collected from various places of Nainital district. The location map of Nainital is given in figure-2. The aim of the present study was also to establish whether allelochemicals from Pinus needles have potential to inhibit seed germination and early seedling growth in studied plants and if there are any changes in the parameters like membrane permeability, malondialdehyde (MDA) content and electrolyte leakage. Allelopathic extract was prepared from Pinus roxburghiineedles collected from Nainital. Dried needles were fine powdered and extracted in 100 cm of distilled water at room temperature for 24 h (2.5, 5 or 10 g). After 24 haours the extract was filtered through a filter paper.