Bioherbicidal Potential of Eucalyptus and Clove Oil and their Combinations on Four Weedy Species

Abstract

Essential oils of eucalyptus leaves and clove buds were isolated and tested for their bioherbicidal potential on different annual weed species. Gas Chromatography-Mass Spectrophotometry analysis (GC-MS) identified thirteen compounds representing around 87.11% of the total isolated eucalyptus oil. The main constituent was 1,8-cineole, which accounted for 68.15% of the total identified compounds. As for clove oil, eleven compounds were identified, representing 90.03% of the total compounds. Eugenol was the dominant compound and accounted for 73.89%. The bioherbicidal efficacy of the two oils and their combinations by three concentrations (2.5, 5, and 10%) were tested on four weedy species, namely Chenopodium album, Raphanus raphanistrum, Melilotus indicus, and Sisymbrium irio. The isolated oils significantly affected the dry weight and inhibited the seedling growth of the four weedy species. Using the two essential oils, individually or within their combinations, showed the highest bioherbicidal efficacy against the targeted weeds in comparison with the synthetic herbicide. In addition, utilization of the two essential oils as natural bioherbicides caused an electrolyte leakage as a result of membrane disruption and loss of integrity of weed seedling tissues. The results showed the possibility of using eucalyptus and clove essential oils individually or in combination as a desirable alternative to synthetic herbicides for sustainable weed management.

Juniperus phoenicea L ve Artemisia herba-alba bitkilerinden elde edilen uçucu yağların allelopatik etkileri birçok yabancı ot türü üzerinde incelenmiştir.

“…25 ml of each solutions were applied to the petri dishes There were 5 replications of each seed species dishes were incubated in a growth chamber at 24±2°C in the dark for a week after that exposed to ambient temperature of the month Aout at (38 ±2)°C Germination was determined by counting the number of germinated seeds at 48h intevals till 7days after 15 days,recorded seed germination percentage, shoot length, root length. [3]…”

Status and Prospects of Botanical Biopesticides in Europe and Mediterranean Countries

“…The main phytotoxic compounds from Syzygium sp. (clove essential oil) are β-caryophyllene, eugenol, and eugenol acetate [ 128 , 129 , 130 , 131 ]. For example, eugenol inhibited the root growth of Avena fatua [ 132 ], Abutilon theophrasti , Amaranthus spp., broccoli ( Brassica oleracea ), Chenopodium album [ 133 , 134 ], Portulaca oleracea , and Urtica urens [ 134 ].…”

“…For example, eugenol inhibited the root growth of Avena fatua [ 132 ], Abutilon theophrasti , Amaranthus spp., broccoli ( Brassica oleracea ), Chenopodium album [ 133 , 134 ], Portulaca oleracea , and Urtica urens [ 134 ]. Additionally, it inhibited the seedling growth of Chenopodium album , Melilotus indicus , Raphanus raphanistrum , Sisymbrium irio [ 131 ], Amaranthus retroflexus , and Brassica oleracea [ 133 ]. Both clove oil and particularly eugenol exhibited herbicidal effects on broccoli leaf, although the presence of leaf epicuticular wax greatly reduced the retention of these oils [ 133 ].…”

“…Eugenol: The phenylpropanoid eugenol is known to elicit the generation of active oxygen species in plants, which leads to cell membrane damage and inhibition of photosynthesis. The enhanced activity of ROS-scavenging enzymes inhibits further metabolic pathways [ 131 , 132 , 133 , 137 , 143 , 144 ].…”

“…Therefore, mixing of lemongrass oil with other essential oils for potential synergistic effects needs further investigations. The phytotoxicity of eucalyptus essential oil mainly refers to the monoterpene 1,8-cineol, causing oxidative stress followed by membrane disruption and electrolyte leakage [ 131 , 146 , 204 ]. It inhibits mitosis by inhibiting G1 phase and several enzymes as p38, resulting in further metabolic interceptions, for example, in photosynthesis and energy metabolism [ 148 ], which lead to cellular damage and death of the target plant [ 205 ].…”