Phytotoxic effects of Cerbera manghas L. leaf extracts on seedling elongation of four monocot and four dicot test species

Abstract

Exploration of allelochemicals with phytotoxic effects is intended to minimize a current dependency on synthetic herbicides in weed management. Several allelochemicals from the tropical tree <em>Cerbera manghas</em> (sea mango) have been reported as termiticides and bactericides. The present study investigated possible phytotoxic effects of <em>C. manghas</em> leaf extracts under laboratory conditions. Four monocots: barnyard grass (<em>Echinochloa crus-galli</em>), foxtail fescue (<em>Vulpia myuros</em>), Italian ryegrass (<em>Lolium multiflorum</em>), and timothy (<em>Phleum pratense</em>) and four dicots: alfalfa (<em>Medicago sativa</em>), garden cress (<em>Lepidium sativum</em>), lettuce (<em>Lactuca sativa</em>), and rapeseed (<em>Brassica napus</em>) were used as test species. Elongation of both shoots and roots of seedlings was measured to assess any phytotoxic effects. The results showed that the sensitivities of shoots and roots were different between the test species, and the inhibition of seedling elongation significantly increased with increasing concentration of leaf extracts of <em>C. manghas</em> for all the test species. The IC<sub>50</sub> (50% inhibitory concentration) values showed that 8.50–32.30 and 4.26–34.67 mg dry weight equivalent extract mL<sup>−1</sup> of <em>C. manghas</em> inhibited seedling elongation by 50%, for shoots and roots respectively. Isolation and identification of the phytotoxic substances from <em>C. manghas</em> are suggested for future investigation.

Herbicidal activity of kidney leaf mud plantain leaves extracts on the germination of four species

“…According to research results, the sensitivity to the extracts depends on the species and also on the concentration of the foliar extract (Bari and Kato-Noguchi, 2017). The seedlings' growth can be stimulated by compounds in low concentration and, on the contrary, can be reduced or inhibited in high concentrations (Kato-Noguchi et al, 2016), a fact observed in this research for the two lettuce cultivars and barnyard grass.…”

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

“…Additionally, at increased the extract concentrations, greater decreases in the growth seedling of test plant species occurred. The concentrationdependent inhibition on tested plants was also found in Rumex maritimus and Cerbera manghas (Bari and Kato-Noguchi, 2017). These results may be due to the variable amount of the potential inhibitory activity depending on the intensity of phytochemicals and may be responsible for the inhibition of the seedling growth of test plants (Travlos and Paspatis, 2008;Gomaa et al, 2014).…”

Allelopathic Potency and an Active Substance from Anredera cordifolia (Tenore) Steenis

“…and timothy ( Phleum pratense L.) were selected as the monocots. The test plants were chosen for the experiment because of their known seedling development behaviors and their common use as model plants for laboratory bioassays [14,15,16,17,18]. Germination percentages of the seeds were >90% on average.…”