Comparative studies of allelopathic effect of composite plant extracts of Alternanthera tenella Colla. and Euphorbia heterophylla L. on Triticum aestivum L.

Abstract

Alternanthera tenella Colla and Euphorbia heterophylla L (Wild Poinsettia) are noxious invasive weed which are found on wastelands, along roadsides and mainly in the vicinity of agricultural crop fields on fallow lands. The study was undertaken to evaluate the allelopathic potential of whole plant aqueous extract of Alternanthera tenella and aqueous leaf extracts of Euphorbia heterophylla on germination and seedling growth of Wheat (Triticum aestivum) from Dist. Pune, Maharashtra, India. Growth and germination parameters of seedlings were affected as concentration increased. Aqueous whole plant extracts of Alternanthera tenella showed 6% of seedling germination whereas Euphorbia heterophylla completely inhibited germination at higher concentration in Triticum aestivum. Root-shoot length and vigor index were significantly reduced from 25% concentration as compared to control (100%). Experiments were conducted in triplicates and under controlled laboratory conditions. It can be concluded that Euphorbia extracts exhibited more phytotoxic effects on growth and germination of Triticum aestivum than Alternanthera tenella. Phytochemical analyses of aqueous and methanolic extracts showed the presence of alkaloids, phenols, flavonoids, tannins, proteins while carbohydrates and saponins were absent in Euphorbia. Whereas, Alternanthera aqueous as well as methanolic extracts revealed the presence of similar phytochemicals as that of Wild Poinsettia. Saponins and phenols were absent in A. tenella. The allelopathic effects may be due to presence of phytochemicals present in the plant.