Allelopathic potential of Sapindus saponaria L. leaves in the control of weeds

Abstract

ABSTRACT. The objective of this work was to evaluate the allelopathic potential of aqueous extracts of young and mature leaves from Sapindus saponaria on diaspore germination and seedling growth of barnyardgrass (Echinochloa crus-galli) and morningglory (Ipomoea grandifolia). The aqueous extract was prepared in a proportion of 100 g of dried, ground leaves dissolved in 1000 mL of distilled water, resulting in a 10% extract concentrate. Dilutions of this concentrate were made with distilled water to 7.5, 5.0 and 2.5%. In seedling growth tests, we compared the effect of these extracts with the herbicide nicosulfuron. Both extracts of mature and young leaves caused delays and reductions in diaspore germination and seedling length of barnyardgrass and morningglory, with the most intense effects observed at a concentration of 10%. The effects of the young leaf extract were more similar to those observed with the herbicide, demonstrating that leaf maturation stage of S. saponaria affects its inhibitory effects on the growth of other plants and that this species is effective in controlling weeds.Keywords: allelopathy, Echinochloa crus-galli, Ipomoea grandifolia, soapberry. Potencial alelopático de folhas de Sapindus saponaria L. no controle de plantas daninhasRESUMO. O objetivo deste trabalho foi avaliar o potencial alelopático do extrato aquoso de folhas jovens e maduras de Sapindus saponaria (sabão-de-soldado) na germinação de diásporos e no crescimento de plântulas de capim-arroz (Echinochloa crus-galli) e corda-de-viola (Ipomoea grandifolia). O extrato aquoso foi preparado na proporção de 100 g de folhas secas e trituradas dissolvidas em 1000 mL de água destilada, produzindo-se o extrato considerado concentrado (10%). A partir deste, foram feitas diluições em água destilada para 7,5; 5,0 e 2,5%. No teste de crescimento de plântulas comparou-se o efeito desses extratos com o herbicida nicosulfuron. Os extratos de folhas maduras e jovens causaram atraso e redução na germinação dos diásporos e no comprimento das plântulas de capim-arroz e corda-de-viola, com efeitos mais intensos na concentração de 10%. No entanto, os resultados obtidos pelo extrato de folhas jovens foram mais similares ao efeito do herbicida, mostrando que o estágio de maturação da folha de S. saponaria interfere nos seus efeitos inibitórios e que esta espécie é eficiente no controle das plantas daninhas.

Alelopatia de acículas de pínus na germinação e desenvolvimento de plântulas de milho, picão preto e alface

“…Estudos relatam a presença de substâncias aleloquímicas de espécies arbóreas, os quais inibem ou interferem na germinação e desenvolvimento inicial de plantas daninhas como Euphorbia heterophylla, Ipomoea grandifolia, Echinochloa crus-galli e Bidens pilosa (INOUE et al, 2010;FORMAGIO et al, 2011;GRISI et al, 2012). Também Mauli et al (2009) Imediatamente após a colheita das acículas, obteve-se o extrato bruto (EB) para ser diluído nas diferentes concentrações.…”

Allelopathic interference of Sapindus saponaria root and mature leaf aqueous extracts on diaspore germination and seedling growth of Lactuca sativa and Allium cepa

“…Allelochemicals may be present in all plant organs such as leaves, stems, roots, fruits, flowers and seeds, and their quantities vary from one tissue to another (Hedge & Miller 1990;Gatti et al 2004;Grisi et al 2012). Leaves appear to be the most consistent source of chemicals involved in phytotoxicity (Dorning & Cipollini 2006), producing the greatest allelopathic effects on target species (Cipollini & Dorning 2006;Tanveer et al 2010).…”

“…In forest science and ecology, there is a lack of knowledge concerning the allelopathic behavior of native tree species (Carmo et al 2007) and this information can contribute to the management of agroforestry systems. Agroforestry systems are more balanced from the environmental and sustainability point of view, and tree species with allelopathic activity may play a crucial role in the stability of these systems, especially with respect to weed control (Grisi et al 2012).…”

Effect of Serjania lethalis ethanolic extract on weed control

“…The application of the stem extracts did not significantly affect the shoot development of these seedlings, but the lowest root length (4.90 mm) was recorded at an estimated concentration of 6.98 mg mL -1 (Figure 2). Grisi et al (2012) reported that aqueous extracts of Sapindus saponaria leaves also inhibited the germination and seedling development of E. crus-galli, showing the phytotoxicity of other species of Sapindaceae in the barnyardgrass control.…”