Foliar Application of Bio-Stimulants Enhancing the Production and the Toxicity of Origanum majorana Essential Oils Against Four Rice Seed-Borne Fungi

Abstract

In the present study, the enhancement of the production of Origanum majorana essential oils (EOs) was studied by treating plants with ascorbic acid (AA) and tryptophan (Trp) at concentrations of 100, 200 and 300 mg/L and Moringa oleifera leaf extract (MLE) at 2.5%, 5% and 10% as foliar applications during the seasons 2018–2019. The toxicities of the EOs were assayed against four seed-borne fungi (Bipolaris orzyae, Curvularia lunata, Fusarium verticilliodies and F. graminearum) isolated from rice grains (Oryzae sativa). Vegetative growth parameters and EO production were enhanced by the application of AA, Trp and MLE in both seasons. Analysis of the EOs by Gas chromatography–mass spectrometry (GC-MS) showed that the main chemical constituents were terpineol (cis-β-(1-terpinenol)), terpinen-4-ol, 4-thujanol (sabinene hydrate), α-terpineol, cymene and sabinene. The highest fungal mycelial growth inhibition (FMGI) percentages against F. verticilliodies were 94.57% and 92.63% as MLE at 5% and 10%, respectively, was applied to plants and 85.60% and 82.19% against F. graminearum as Trp was applied to plants at 300 and 200 mg/L, respectively. EOs from the treated plant with MLE (10%) observed the highest FMGI (84.46%) against B. oryzae, and EOs from plants treated with AA as foliar application at 300 and 200 mg/L showed the highest FMGI values of 81.11% and 81.85%, respectively, against the growth of C. lunata. Application of EOs extracted from plants treated with Trp, AA and MLE at 300 mg/L, 300 mg/L and 10%, respectively, or untreated plants to rice seeds inhibited or decreased the fungal infection percentage from 82.5% (naturally infected grains) to 1.75%, 10.5%, 17.5% and 18.5%, respectively. In conclusion, the extracted EOs affected by the foliar application of O. majorana plants with Trp, AA, and MLE could be useful as a biofungicide against rice seed-borne fungi.

Productivity and Post-Harvest Fungal Resistance of Hot Pepper as Affected by Potassium Silicate, Clove Extract Foliar Spray and Nitrogen Application

“…Fruit characteristics and yield were little, yet positively affected by the foliar application of CWE. It is evident that the foliar application of several types of extracts would exert a bio-stimulation effect on the growth and development of several plant species, for example, tomato [ 49 ], Origanum majorana [ 50 ], and geranium plants [ 51 ]. This might be attributed to the promoted biomass production as a result of enhancing the shoot and root fresh weights.…”

Evaluation of Seven Essential Oils as Seed Treatments against Seedborne Fungal Pathogens of Cucurbita maxima

“…Perczak et al [ 41 ] reported that essential oils have great potential for inhibition of growth of Fusarium fungi on maize seeds. An O. majorana essential oil was shown to have antifungal activities against four seedborne fungi in rice: Fusarium verticilliodies , Fusarium graminearum , Bipolaris oryzae , and Curvularia lunata [ 42 ]. Van der Wolf et al [ 43 ] showed that thyme, oregano, cinnamon, and clove essential oils can reduce fungi on cabbage seeds, using the blotter method.…”

New Approach for Using of Mentha longifolia L. and Citrus reticulata L. Essential Oils as Wood-Biofungicides: GC-MS, SEM, and MNDO Quantum Chemical Studies

“…All the compounds were identified using their retention times and mass spectra by matching them with those from WILEY 09 and NIST 11 mass spectral databases. Standard Index and Reverse Standard Index measurements, with the Xcalibur 3.0 data system (3.0, Thermo Fisher Scientific Inc., Austin, TX, USA, 2014) of GC/MS, were used to confirm the identification of the compounds, where a value ≥650 is acceptable to confirm the compounds [ 6 , 7 , 15 , 16 , 17 , 18 , 19 , 20 , 45 ].…”

“…Essential oils (EOs)—aromatic substances—can be obtained from different plant parts such as leaves, flowers, seeds, fruits, bark, wood, and roots by extraction using steam or hydrodistillation. Some plant EOs have recently been proven to be successful as ecofriendly biocontrol agents, with antibacterial, antifungal, antioxidant, insecticidal, and antiviral properties [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], and have potential uses as natural additives and wood-biofungicides [ 2 , 3 , 4 , 6 , 7 ] and in the food industry, [ 22 , 23 , 24 , 25 ].…”