Soil or Vermiculite-Applied Microencapsulated Peppermint Oil Effects on White Mustard Initial Growth and Performance

Abstract

Microencapsulated peppermint (Mentha x piperita L.) essential oil (MPEO) is a prospective botanical herbicide. A hypothesis was formulated, that the type of growth medium (vermiculite or silty clay loam soil substrate) affects the phytotoxic potential of MPEO. A pot experiment in a randomized design assessed the effect of five doses of MPEO in a range of 0–108 g m−2 or 0–145 g m−2, mixed with vermiculite or with soil, respectively, on early growth of white mustard (Sinapis alba L. cv. Zlata), tested here as a model “weed” species. The morphologic analyses were supported by selected biochemical measurements. The two highest doses of microcapsules (from 73 to 145 g m−2) caused a significant decrease of plants’ height and biomass. An increase of anthocyanin content in the aboveground parts of mustard is supportive for the induction of defense mechanisms against MPEO-triggered stress in mustard leaves. In conclusion, MPEO appears as a promising bio-herbicide. However, we are aware that further studies on the mechanisms of action of MPEO in different weed species are necessary to test (i) whether or not the effect is consistent to be proficiently exploited for weed control in field and (ii) to deepen the biochemical and physiological reactions by the plants against MPEO treatments.

The Phytotoxicity of Microencapsulated Peppermint Oil on Maize (Zea mays L.) Depending on the Type of Growth Substrate and Maize Cultivar

“…We hypothesize that vermiculite could alleviate the adverse effects of the MPEO on maize by supporting physical conditions of its initial growth. Contrarily to our findings, vermiculite was less supportive of the initial growth of white mustard in the presence of the MPEO than clayey soil [19]. As authors speculate, this difference could result from higher amounts of nutrients in the soil than vermiculite, which promoted buildup of the mustards' biomass [19].…”

“…Contrarily to our findings, vermiculite was less supportive of the initial growth of white mustard in the presence of the MPEO than clayey soil [19]. As authors speculate, this difference could result from higher amounts of nutrients in the soil than vermiculite, which promoted buildup of the mustards' biomass [19]. In case of initial growth of maize, the availability of nutrients in the growth substrate could be of lower importance, as the kernel could support them [42].…”

“…The mustard growth impairment in vermiculite was visible at a dose of 73.0 g m −2 , whereas in the soil-at 108.0 g m −2 of MPEO. In the presence of vermiculate and the MPEO mustard was higher and had more hydrated tissues, as compared to the mustard in the clayey soil with the MPEO [19].…”

“…In a previous experiment, we showed that susceptibility of a species to the MPEO could be, to some extent, modified by the type of a growth substrate, i.e., white mustard (Sinapis alba L. 'Zlata') was more tolerant to the presence of MPEO in the clayey soil than in the vermiculite [19], which is a hydrous phyllosilicate mineral, chemically and biologically inert [20]. The mustard growth impairment in vermiculite was visible at a dose of 73.0 g m −2 , whereas in the soil-at 108.0 g m −2 of MPEO.…”

Secondary Metabolites and Eco-Friendly Techniques for Agricultural Weed/Pest Management

“…Three of the twelve published manuscripts are focused on the potential use of the essential oils (EOs) formulations for weed management [ 10 , 11 , 12 ].…”