Effect of essential oil of seven medicinal plants on longevity, nongermination, qualitative and quantitative traits of Solanum tuberosum cv. Agria

Abstract

There is increasing interest in the application of natural plant extracts for the postharvest management of food crops. This study investigates the potential for hydro-distilled natural essential oils to inhibit the germination of potato tubers in storage. Four completely randomized design experiments were undertaken with extracts of seven medicinal plants [(Zataria multiflora L.), peppermint (Mentha piperita L.), fennel (Foeniculum vulgare L.), summer savory (Satureja hortensis L.), cloves (Eugenia caryophylium L.), lavender (Lavandula officinalis L.), and black cumin (Bunium persicum L.)], at four concentrations (0, 150, 300, and 450 μl/L) and three replications. Tubers were treated with essential oil vapor and then stored for 6 months at 8°C in the dark. Peppermint and fennel essential oils, at a concentration of 300 μl/L, completely inhibited tuber germination. In pregermination experiments, the dimensional and mass weight of tubers before germination increased by 18.4% and 21.11%, respectively, in the control treatment compared with the treated tubers with a concentration of 150 μl/L. However, the highest rate for the mentioned parameters in postgermination experiments was observed at a concentration of 300 μl/L fennel treatments. Peppermint and fennel essential oil with a concentration of 300 μl/L completely inhibited germination and tubers had acceptable volume, mass, dry matter, protein, and potassium. Also, the highest concentration of sugar (44.44 mg/g) occurred in tubers treated with fennel (300 μl/L), but the starch levels were lower than in tubers treated with the other essential oils. From these results, peppermint essential oil was identified as the best treatment and it is recommended for use in commercial harvests. Novelty impact statement Plant essential oils are safe substances for the environment and human health. Therefore, for the first time, these essential oils with different concentrations were evaluated for an Iranian potato cultivar. The innovation of this article was the use of a range of concentrations and diversity of important plant essential oils to provide a novel solution for Iranian farmers in controlling potato germination and storage conditions.