Mulching with almond hull and olive leaves for weed control in fennel (Foeniculum vulgare Mill.) and flower beds

Weeds are a major problem in cropping systems and in urban areas. The aim of this study was to assess the effectiveness of organic mulching with olive leaves and almond hulls to control weeds in fennel (Foeniculum vulgare Mill.) and in flower beds (urban areas). A 3-cm thick layer of olive leaves or almond hulls was applied as mulching material in fennel. Control consisted of both an unmulched treatment and a weed free control. Moreover, in a flower bed of a railway station, plots mulched with 3 cm layer of olive leaves and almond hulls were compared with an unmulched treatment. Weed infestation was evaluated and the weights of the whole plant and of the marketable part of fennel (grumolo) measured. Mulching with olive leaves and almond hulls reduced weed infestation in both vegetable crop and flower beds. However, olive leaves reduced the weights of the whole plant and of the grumolo. The adoption of almond hulls and olive leaves as organic mulches could be an effective strategy for weed control. Further investigations should be carried out to assess whether the effectiveness of these mulching materials is mainly due to a mechanical activity or allelopathic compounds also play a significant role in weed suppression

Physicochemical Properties, Antioxidant and Antimicrobial Activities of Fennel (Foeniculum vulgare Mill) Seed and Leaf Oils

Foeniculum vulgare Mill. Commonly known as fennel has been used in traditional medicinal plant belonging to Apiaceae. The aim of this study was to examine quality and biological activities of fennel seed and leaf oils. The oil extraction was done in Soxhlet apparatus using hexane as a solvent. The result for physicochemical properties presented significantly higher oil yield (4.39%) and peroxide value (3.90) was observed for seed oil. Significantly higher antioxidant activities with respect to DPPH (24.45±3.74) and hydrogen peroxide (62.70±0.28) free radical scavenging activities for leaf oil. However, ascorbic acid was found to be significantly higher for seed oil (82.44±4.63). The strongest antibacterial activity with maximum zone of inhibition (14.25mm), minimum inhibitory concentration (MIC, 0.25µl/ml) and corresponding minimum bactericidal concentration (MBC, 0.50 µl/ml) was recorded for leaf oil extract against Staphylococcus aureus. On the other hand, the strongest antifungal activity with maximum zone of inhibition (13.50mm), MIC (0.38µl/ml, the least value) and minimum fungicidal concentration (MFC, 0.75µl/ml) was recorded for leaf oil against Aspergillus Niger. It can be observed from the result in this study that leaf oil extract has demonstrated more effective biological activities including both antioxidant and antimicrobial potentials.

Foeniculum vulgare Miller, a New Chemotype from Montenegro

Previous studies relating to prolonged and fractionated distillation procedures highlighted essential oils’ (EOs) chemical composition to be significantly dependent on the extraction duration and harvesting time. As a continuation, a hydrodistillation procedure was applied to ripe fruit material of fennel, Foeniculum vulgare Miller (Apiaceae), collected from three localities in Montenegro (Podgorica, Nikšić, and Kotor) to furnish a total of 12 EOs. Liquid and vapor phases of the samples were analyzed by Gas Chromatography/Mass Spectrometry and Headspace-Gas Chromatography/Mass Spectrometry techniques, and 18 compounds have been identified. Although both quantitative and qualitative differences between the samples were notable, the phenylpropanoids anethole (ANE) and estragole and the monoterpenoids α-terpineol (TER) and fenchone (FEN) could be singled out as the most abundant constituents. The EOs from Podgorica belong to the most common ANE-rich chemotype, while the predominance of the monoterpenoid fraction is characteristic of the samples from Nikšić and Kotor. The latter is particularly rich in TER (up to 56.5%), with significant amounts of FEN and ANE. This chemical profile could represent a new chemotype of fennel EO. Vapor phases contained mainly monoterpenoids, with increased amounts of FEN and TER, while the number of phenylpropanoids was significantly decreased.

Thermosonication Process Design for Recovering Bioactive Compounds from Fennel: A Comparative Study with Conventional Extraction Techniques

This study aimed to examine the impact of the combination of acoustic energy at the nominal powers of 100, 200, 300, and 400 W with moderate heat processing at 40, 50, and 60 °C on the extraction of phytochemical compounds from Foeniculum vulgare. Thermosonication processing, based on high-intensity ultrasound combined with an external heat source, can potentialize the extraction of soluble solids from plant material. However, the excessive temperature increase generated by the two energy sources during thermosonication treatment may degrade the thermolabile bioactive compounds. Regardless of the temperature condition, fennel extracts obtained at 400 W presented lower total phenolic content (TPC) than those obtained at 300 W. The cavitation heat and mechanical stress provided at 400 W may have degraded the phenolic compounds. Thereby, the best extraction condition was 300 W and 60 °C. The fennel extract presented the highest content of TPC (3670 ± 67 µg GAE/g) and antioxidant activity determined by DPPH and ABTS methods (1195 ± 16 µg TE/g and 2543.12 ± 0.00 µg TE/g, respectively) using this treatment. Thermosonication can be an innovative technique for extracting phytochemicals because it provides good results in shorter processing times, with 73% and 88% less energy consumption than Percolation and Soxhlet techniques, respectively.