Allelopathic Performance of Medicinal Plants on Traditional Oilseed and Pulse Crop of Central Himalaya, India

Abstract

The present study was aimed to determine the allelopathic effect of aqueous extract of above ground (AG) and below ground (BG) part of four medicinal plants (MAPs) viz., Picrorhiza kurroa, Asperagus racemosus, Ocimum sanctum and Valeriana wallichii on germination and seedling growth of some traditional food and oilseed crops. The aqueous extract of AG and BG part of the studied MAPs at 2 % significantly reduced the germination, plumule and radicle growth of the selected pulse and oil seed crops in bioassays. The results of the present experiments revealed that MAPs have inhibitory effect on food and oilseed crops owing an occurrence of allelochemicals.Keywords Medicinal plants Á Allelopathy Á Aqueous extract Á Oilseed crops Á Pulses Indian Himalaya has been recognized rich in medicinal and aromatic plants [MAPs] [1]. However, as a result of anthropogenic activity to collect the MAPs illegally and legally from natural habitat, the population of MAPs decreased at an alarming rate and rendered them under threat, vulnerable, extinct and endangered category [2, 3]. Hence, to maintain long term sustainability and conservation of this wild wealth, domesticated cultivation is obviously an alternate option [4]. Though, indigenous communities in mountain Himalaya are accustomed to cultivate a variety of food crops, cereales, oilseed crops, millets and certain cash crops in settled terraced agriculture fields. However, low agricultural productivity coupled with lack of appropriate technologies to enhance the crops yield has enforced mountain people to adopt new and profitable venture like cultivation of medicinal plants. Allelopathy is an important interference mechanism wherein one plant releases bioactive chemicals into the surrounding environment that affect the growth of other plants [5]. These chemicals are largely classified as secondary plant metabolites (such as alkaloids, isoprenoids, phenolics, flavonoids, terpanoids and gluconolates etc.). Allelochemicals are present in virtually all plant tissues, including leaves, flowers, fruits, stems, roots, rhizomes, seeds and pollen. The phytotoxic effects of substances released by leaching, root exudation and residue decomposition of certain plants on germination and seedling growth of the associated plants have been amply demonstrated [6][7][8][9]. However, none of the study is known on the allelopathic behaviour of medicinal plants on germination and seedling growth of the traditional oil seed and pulse crops from Indian Himalayan region. Keeping in view the paucity of data on allelopathic influence of medicinal plants on traditional crops, the present study was initiated with the objectives to determine the effect of few plant species of MAPs that are being cultivated by the farmers viz., Picrorhiza kurroa, Asperagus racemosus, Ocimum sanctum and Valeriana wallichii on germination and growth of some important traditional oilseeds and pulse crops to understand the allelopathic behavior of medicinal plants on food and oil seed crops in a multi-cropping system....

Evaluation of the Allelopathic Potential of Leaf Extracts from Dischidia imbricata (Blume) Steud. on the Seedling Growth of Six Test Plants

“…Therefore, greater attention has been focused on the study of the allelopathic effects of medicinal plants and its potential application for weed control. More recently, some medicinal plants have been reported to possess allelopathic activity such as Ocimum tenuiflorum (Islam and Kato-Noguchi, 2013), Acacia concinna (Boonmee and Kato-Noguchi, 2017), Aspergus racemosus, Picrobiza kurroa, Valeriana wallichii, Ocimum sanctum (Rawat et al, 2016), and Melia azedarach (Shinwari et al, 2017). Therefore, these results suggested that medicinal plants with inhibitory activity may contain allelopathic compounds.…”

Bioprospecting neglected botanicals as phyto-fertilizers for underutilized food crops

“…They found out that rice husk extract at 2% concentration level completely inhibited germination of cowpea seeds. In addition, the inhibitory effects of Picrorhiza kurroa, Asperagus racemosus, Ocimum sanctum, Valeriana wallichii (Rawat et al, 2016) and Ocimum basilicum L. (Verma et al, 2012) on germination and seedling growth of seed crops are in line with NL on sesame seeds. The effect of NA on sesame germination is detrimental, which suggests allelopathy.…”

Allelopathic activity of Acacia concinna pod extracts

“…Nasrine et al (2011) discovered that aqueous extracts of two medicinal plants (Euphorbia guyoniana and Retama retam) inhibited the germination of two invasive weeds (Bromus tectorum and Melilotus indica) and a common wheat (Triticum aestivum). Rawat et al (2016) also found that aqueous extracts of different plant parts extracted from four medicinal plants (Asperagus racemosus, Picrorhiza kurroa, Valeriana wallichii and Ocimum sanctum) affected development and significantly reduced the seed germination of the pulse and oilseed crops. These results also indicated that the inhibitory activity of the medicinal plants was due to the occurrence of allelochemicals.…”