Phytochemical screening of selected plants and their allelopathic effect on germination of bean and radish seeds

Abstract

The study of ethno-botanical is important in different sectors like medical and agriculture so the discovery, exploration and documentation of such plants is necessary. This research assessed the phytochemicals present in the selected plants and studied their allelopathic effect on germination, radicle length, and plumule length of bean and radish seeds. The research was conducted in the Agroecology lab of Institute of Agriculture and Animal Sciences (IAAS ), Paklihawa. Six plants such as Camellia sinensis, Zanthoxylum armatum, Amomum subulatum, Eupatorium glandulosum, Cymbopogan flexuosus, and Rhododendron arboreum were selected and collected from different dis- tricts of Nepal. The collected plant parts were dried, powdered, and aqueous extract was used to screen some secondary metabolites. Six treatments @ 10% aqueous concentration of extracts and a control were applied in bean and radish seeds in CRD format along with 3 replications to study their allelopathic effect. Glycoside was detected in all the extracts, and alkaloid was also detected in all the extracts except in the extract of Rhododendron ar- boreum. Alkaloids, flavonoids, terpenoids, and saponins were found highest in Eupatorium glandulosum leaves (5.2%), Camellia sinensis (1.4%), Cymbopogan flexuosus (7.03%), and Camellia sinensis (2.12%), respectively. The reading of germination rate for bean and radish seeds was found lowest in Camellia sinensis extract and Eupatorium glandulosum extracts, respectively. Average length of radicle and plumule of both bean and radish seeds was found highest in the extract of Rhododendron arboreum and least in an extract of Eu- patorium glandulosum. In conclusion the selected plants had many secondary metabolites that inhibited the development of the bean and radish seeds to grow vigorously hence upon further research and trial, these plants could be a wonderful source of herbicides to suppress the growth of unwanted weeds in the field.