## 2 Phytotoxic Effects of Volatile Terpenes from the Lamiaceae Family
### Advantages of Water Emulsions of Nepeta Essential Oils
By supplementing the synthetic formulations, EOs can result in lower chemical residues in soil, water, and crops, promoting healthier ecosystems and reducing the potential for adverse effects on human and animal health otherwise caused by synthetic herbicides [125; 126; 11]. While synthetic herbicides often act on a specific group of plants in the field (e.g., dicotyledonous or monocotyledonous and broadleaf or grass weeds), EOs can be more selective and control weeds without harming the crop, which has so far mainly been demonstrated under laboratory conditions. [PERSON] et al. [38] found that EO from _Nepeta tranjensis_ (_N_r_EO) and pure monoterpenoids, such as \(\alpha\)- and \(\beta\)-pinene, effectively inhibited the seed germination of _Stellaria media_, while _Brassica napus_ showed resistance. In addition, [PERSON] et al. [127] showed that crops generally have a greater tolerance to EO than weeds. Of the 12 EOs tested, the most phytotoxic group, consisting of _Carum carvi_ L., _Thymus vulgaris_ L., _Mentha\(\times\)_piperita_ L., and _Salvia officinalis_ L. EOs, was rich in oxygenated monoterepenes, while the least phytotoxic EO (_Solidago canadensis_ L.) consisted mainly of mono- and sesquiterpene hydrocarbons. Weeds such as _Amaranthus retroflexus_ L. and _Centaurea cyanus_ L. were the most affected, while corn (_Zea mays_ L.) showed the highest tolerance to EO treatments. This result underscores the potential of EOs as selective bioherbicides that provide effective weed control while minimizing negative effects on crops. Research indicates that the use of herbicide mixtures with different modes of action can be more effective in preventing herbicide resistance in weed species [128; 129]. The application of glufosinate in combination with other synthetic herbicides at different crop growth stages has been shown to be an effective strategy for weed control [130; 131; 132]. This integrated approach improves weed control and reduces the risk of resistance development in weeds by simultaneously targeting multiple biochemical pathways. Nevertheless, antagonistic effects have been reported in some cases [133]. [PERSON] et al. [134] gave an overview of the research on plant-based EOs in combination with insecticides and fungicides and emphasized their potential to reduce the minimum inhibitory concentrations of pesticides to synergistically control plant pests and phytopathogenic fungi. Plant EOs of lavender and thyme can synergize the toxicity of imidalcoprid, a conventional insecticide against _Myzus persicae_ (Hemiptera: Aphididae), by 16- to 20-fold [135]. Findings from various studies suggest that multiple factors impact the effectiveness of mixed herbicide interactions. Key aspects include the rate of absorption, movement within the plant, metabolic transformation, and competition for common binding sites, among others [129; 130; 131]. Although some EOs such as lemongrass, pine, clove, cinnamon, and citrus oils have already been commercialized and successfully launched in organic farming [136; 137; 123], to our knowledge, there is currently no herbicide mixture of synthetic herbicides and EOs on the market. Commercially available organic herbicides are generally intended for weed control in households and small farms, where their effectiveness is limited. In  
Figure 3: Physiological responses of target plants to neepetalactone or phloretin treatment. CAT—Catalase; GS—Glutamine synthetase; IAA—Indole-3-acetic acid; OxIAA—Oxoindole-3-acetic acid; PAT—Polar auxin transport; POX—Perooxidase; SOD—Superoxide dismutase. conventional cropping systems, their efficacy is insufficient as many weed species recover over time [123]. A promising transitional solution to overcoming this challenge is the development of formulations that combine synthetic herbicides with bioherbicides. Such formulations are expected to reduce the environmental and health risks associated with synthetic herbicides while improving the effectiveness of weed control and promoting sustainable agricultural practices. [PERSON] et al.