Allelopathic Influence of Residues from Sphagneticola trilobata on Weeds and Crops

Abstract

-The allelopathic effect studied in many cultures has currently generated great expectations that displayed a natural and environmentally friendly tool for weed management using bioherbicides. The objective of this work was to assess allelopathic influence of residues of S. trilobata on the germination and growth of weeds, as well as their relation with some crops and effects on soil properties. Results show that residues from S. trilobata have inhibited the germination of weeds (31.6 -72%), increasingly with the applied dose. All residue doses of this specie have inhibited dicotyledonous germination, but only maximum concentration has affected monocotyledons. The residues did not affect onion germination, but stimulated it in radish and tomato, while the dose applied at 50% produced tomato stimulation and inhibition of cabbage. The effects of residues on hypocotyl growth in different crops showed changes in species response. For onion, the three doses had negative effects on the growth of hypocotyl, while tomato was stimulated. For radish, the growth was hindered by any dose applied, and were only different (50 and 100%) compared to control. For cabbage, only hypocotyl length was stimulated, when maximum dose (100%) was applied. For the radicle growth, in onion and radish no differences were found compared to control. While the tomato radicle growth was inhibited, in cabbage, all doses encouraged the elongation of the radicle. The dry mass of weed was affected by increased dose of residue (0.49 -8.8 g m -2 ), however the soil microflora was stimulated, while the population of Azotobacter spp. was not affect. Some soil properties were affected, the level of organic material, Na+ and electrical conductivity were increased, while pH (H 2 O) decreased a bit, however it remained basic. Keywords: allelopathy, residues, Azotobacter, soil microflora. (31,6 -72%) RESUMO -Atualmente, o efeito alelopático estudado em muitas culturas tem gerado grandes expectativas que exibiam uma ferramenta natural e ambientalmente amigável para manejo de plantas daninhas usando os bioherbicidas. O objetivo deste trabalho foi avaliar a influência alelopático de resíduos de S. trilobata na germinação e crescimento de ervas daninhas, bem como sua relação com algumas culturas e os efeitos sobre as propriedades do solo. Os resultados mostram, que os resíduos de S. trilobata produziram uma inibição da germinação das ervas daninhas

Allelopathic Effects of Giant Sensitive Plant (Mimosa pigra) Leaf Powder on Germination and Growth of Popping Pod and Purslane

“…Several studies have shown that various allelopathic plants caused both suppression and stimulation of growth of the tested species (Hong et al, 2004;Batish et al, 2007;Hernández-Aro et al, 2016). However, the results obtained in this study are the first report on the allelopathic potential of M. pigra.…”

“…Nekonam et al (2014) suggested that variability in allelopathic expression in a plant might be due to the different nature of allelochemicals released by the species. There are various direct modes of action of allelochemicals on plant growth and metabolism, cell division, cell elongation, membrane permeability, mineral uptake, photosynthesis, respiration and specific enzyme activity, whereas there are indirect effects on soil properties and nutrient cycling (Rice, 1984;Weir et al, 2004;Farooq et al, 2013;Hernández-Aro et al, 2016). From the results, M. pigra leaf powder showed both inhibition and stimulation effects on the germination and plant growth.…”

“…This might have been due to an association between the allelochemicals and the soil properties (Bhadoria, 2011). Hernández-Aro et al (2016) reported that allelochemicals from plant residues were changed by soil microbial populations and this affected soil physicochemical properties including an organic material, electrical conductivity and the pH value. Therefore, the allelopathic effects on germination and plant growth by the M. pigra leaf litter might be attributed to both allelopathic effects and their physical presence in the soil or to soil properties associations.…”

Impacts of Smooth Pigweed (Amaranthus hybridus) on Cover Crops in Southern Ontario

“…Indeed, in the case of oilseed radish treated with tea, we observed an increase in shoot weight at low concentrations, but no change in shoot weight when plants were exposed to higher concentrations. Hernández-Aro et al [43] report that the shoot growth of radish (variety not indicated) is stimulated by a 50% concentration of organ extract from creeping-oxeye (Sphagneticola trilobata L.), relative to 100%. However, radish (var.…”

Bioatividade de óleos essenciais na germinação e no vigor em sementes de tomate

“…O efeito alelopático de óleos essenciais e de extratos de plantas já foi comprovado em alguns estudos e indica as potencialidades do uso dos metabólitos secundários presentes nas diversas espécies vegetais, tais como S. trilobata em tomate, cebola, rabanete e repolho (HERNÁNDEZ-ARO et al, 2016); Araucaria angustifolia em alface (SILVEIRA et al, 2014); Plectranthus barbatus em Amaranthus delexus (LESSA et al, 2017); Pachyrhizus erosus L. em Euphorbia heterophylla e Bidens pilosa (BARBOSA et al, 2018); Anacardium occidentale em tomate e alface (MATIAS et al, 2017); picão preto (Bidens pilosa L.) em feijão comum (Phaseolos vulgaris L.) (COELHO et al, 2014).…”