Lavender as a Source of Novel Plant Compounds for the Development of a Natural Herbicide

Abstract

In a previous study, lavender (Lavandula spp.) was found to be highly phytotoxic towards annual ryegrass (Lolium rigidum, ARG), a major weed of winter wheat crops in Australia. This research aimed to further explore this relationship and determine the chemical(s) responsible for the observed effect. In bioassay, it was determined that the stem and leaf extract of L. x intermedia cv. Grosso ranked highest and had the potential to reduce significantly the root growth of several plant species. An extract concentration of 10% almost completely inhibited ARG root growth. When the extract was tested for stability, there was no loss in phytotoxicity after the 256 day trial. Via bioassay-guided fractionation and chromatographic techniques, it was determined that the sub-fraction consisting of coumarin and 7-methoxycoumarin was most phytotoxic towards ARG. Chemoassays of 18 structural analogues of coumarin showed that coumarin itself was the most phytotoxic and largely responsible for the observed phytotoxicity of the extract. Soil trials were conducted using pure coumarin and the lavender extract, and in both instances, shoot length and weight were significantly reduced by post-emergence application at all concentrations evaluated.

Herbicidal potential of lavender (Lavandula angustifolia Mill.) essential oil components on bristly foxtail (Setaria verticillata (L.) P. Beauv.): Comparison with carvacrol, carvone, thymol and eugenol

“…The essential oils of some aromatic plants exhibit contact and fumigant insecticidal, bactericidal and fungicidal actions [1][2]. Additionally, phenolic and terpenic components of essential oils have been reported by several researchers as inhibitors of vegetation and growth [3][4][5][6][7][8][9][10][11][12]. In the course of evaluation of lemonscented gum (Eucalyptus citriodora Hook.…”

Fitotoxicidad De Aceites Esenciales Y Extractos Acuosos De Plantas Mediterráneas Para El Control De Arvenses

“…Numerosas especies del género Lavandula han mostrado actividad biológica (Haig et al, 2009). Se han descrito las propiedades antimicrobianas (Romeo et al, 2008;Roller et al, 2009), antifúngicas (Moon et al, 2007), antiparásitas (Moon et al, 2006) e insecticidas (Papachristos y Stamopoulos, 2004;Pavela, 2005) de aceites esenciales de diferentes especies de Lavandula.…”

“…mostraron alta fitotoxicidad frente a Lolium rigidum (Haig et al, 2005). Se comprobó que la cumarina y la 7-metoxicumarina eran responsables de esta actividad (Haig et al, 2009).…”

Phytotoxic mechanisms of bur cucumber seed extracts on lettuce with special reference to analysis of chloroplast proteins, phytohormones, and nutritional elements

“…The release of allelochemicals from plants or their decomposed residues into the soil inhibits weed growth . Moreover, herbicides from natural sources may prevent weed growth without environmental damage (Haig et al, 2009). Various allelochemicals containing extracts have been tested on seeds and seedlings and their detrimental effects can inhibit seed germination and cause abnormalities in roots and shoot growth (Tigre et al, 2012).…”