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

Agnieszka Synowiec,Agnieszka Krajewska

doi:10.3390/plants9040448

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.

Highlights

Peppermint (Mentha x piperita L.), a natural hybrid of Mentha aquatica L. and Mentha spicataL., is cultivated broadly in the world
We are aware that further studies on the mechanisms of action of microencapsulated peppermint EO (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
Based on the hydrodistillation analysis, the average content of peppermint essential oil (EO) in the microcapsules was of 0.96 ml per 10 grams of microcapsules, equal to 9.6% of EO in the microcapsules (v/w)

Summary

Introduction

Peppermint (Mentha x piperita L.), a natural hybrid of Mentha aquatica L. and Mentha spicataL., is cultivated broadly in the world. Peppermint (Mentha x piperita L.), a natural hybrid of Mentha aquatica L. and Mentha spicata. It is a valuable species due to production of essential oil (EO), applied in different industries [1,2]. That peppermint EO displays significant allelopathic and phytotoxic potential, by inhibiting germination and early growth of various weeds [3]. This potential is attributed to the main compounds of the peppermint EO-oxygenated monoterpenes, namely menthol and menthone constituting together 45%–80% of the oil [4]. According to Synowiec et al [5], these compounds are mainly responsible for the allelopathic potential of EOs.

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Results

Discussion

Conclusion