Biocontrol Activity of Aromatic and Medicinal Plants and Their Bioactive Components against Soil-Borne Pathogens

Abstract

Soil-borne phytopathogens can have detrimental effects on both cereal and horticultural crops resulting in serious losses worldwide. Due to their high efficiency and easy applicability, synthetic pesticides are still the primary choice in modern plant disease control systems, but stringent regulations and increasing environmental concerns make the search for sustainable alternatives more pressing than ever. In addition to the incorporation of botanicals into agricultural practices, the diversification of cropping systems with aromatic and medicinal plants is also an effective tool to control plant diseases through providing nutrients and shaping soil microbial communities. However, these techniques are not universally accepted and may negatively affect soil fertility if their application is not thoroughly controlled. Because the biocontrol potential of aromatic and medicinal plants has been extensively examined over the past decades, the present study aims to overview the recent literature concerning the biopesticide effect of secondary metabolites derived from aromatic and medicinal plants on important soil-borne plant pathogens including bacteria, fungi, and nematodes. Most of the investigated herbs belong to the family of Lamiaceae (e.g., Origanum spp., Salvia spp., Thymus spp., Mentha spp., etc.) and have been associated with potent antimicrobial activity, primarily due to their chemical constituents. The most frequently tested organisms include fungi, such as Rhizoctonia spp., Fusarium spp., and Phytophthora spp., which may be highly persistent in soil. Despite the intense research efforts dedicated to the development of plant-based pesticides, only a few species of aromatic herbs are utilized for the production of commercial formulations due to inconsistent efficiency, lack of field verification, costs, and prolonged authorization requirements. However, recycling the wastes from aromatic and medicinal plant-utilizing industries may offer an economically feasible way to improve soil health and reduce environmental burdens at the same time. Overall, this review provides comprehensive knowledge on the efficiency of aromatic herb-based plant protection techniques, and it also highlights the importance of exploiting the residues generated by aromatic plant-utilizing sectors as part of agro-industrial processes.

Status of Pesticide Use among Thyme (Thymus vulgaris) Crop Farmers in North West Bank, Palestine

“…Not applicable the relationship between pesticide application and production variables, except for the relationship between the safe period and the duration of thyme harvest. The application of different pesticides did not enhance thyme productivity, as aromatic plants and their bioactive metabolites can impact plant diseases by inducing systemic resistance, defense responses, and inhibiting the growth of pathogens (Greff et al, 2023). The mean duration was approximately 50.22 ± 17.74 days for the applicable safety period, whereas it was 32.38 ± 13.58 days for the non-applicable period (Table 7).…”

Sustainable Waste Management in the Production of Medicinal and Aromatic Plants—A Systematic Review

“…MAP by-products may be rich in bioactive compounds of interest and beneficial microorganisms. Hence, they can be used as natural biopesticides or organic fertilisers, which may suppress the growth of soil-borne phytopathogens [27]. Under a circular economy approach, the use of these residues is also recommended for the restoration of degraded and marginal lands [23].…”

“…Through composting and vermicomposting technologies, these by-products can be used to improve relevant soil processes and provide nutrients [27]. Composting has become a very important sustainable approach to recycle medicinal herbal residues [29] and it allows the conversion of organic waste into stabilised soil amendments, under aerobic conditions [25].…”

Legal Protection of New Plant Varieties: Lamiaceae Patent Cases Based on International Patent Classification

“…Medicinal and aromatic plants play a significant role in sustainable agricultural development. Their cultivation diversifies crops, helps conserve biodiversity, reduces the use of chemicals, improves soil health, creates income for farmers, promotes sustainable agriculture, and conserves traditional knowledge [4,5]. These facts show the relevance of encouraging innovation in agriculture, especially that directly related to the development and selection of plant varieties expressing traits of interest [6].…”