A natural post-emergence herbicide based on essential oil encapsulation by cross-linked biopolymers: characterization and herbicidal activity

A review on the encapsulation of "eco-friendly" compounds in natural polymer-based nanoparticles as next generation nano-agrochemicals for sustainable agriculture and crop management

Crop management techniques and sustainable agriculture offer a comprehensive farming method that incorporates social, economic, and ecological factors. Sustainable agriculture places a high priority on soil health, water efficiency, and biodiversity conservation in order to develop resilient and regenerative food systems that can feed both the current and future generations. Our goal in this review is to give a thorough overview of current developments in the use of polysaccharides as raw materials for the encapsulation of natural chemicals in nanoparticles as novel crop protection products. The search for recent research articles and latest reviews has been carried out through pubmed, google scholar, BASE as search engines. Offer cutting-edge solutions for sustainable crop management that satisfy the demands of an expanding population, comply with changing legal frameworks, and address environmental issues by encasing natural compounds inside polysaccharide-based nanoparticles. A variety of natural substances, such as essential oils, plant extracts, antimicrobials compounds and miRNA, can be included in these nanoparticles. These materials have many advantages, such as biocompatibility, biodegradability and controlled release of active compounds. Thanks to their action mechanism, they are able to mediate hormone signaling and gene expression in different plant physiological aspects, as well as enhance their tolerance to abiotic stress conditions. Sustainable agriculture can be supported by this type of treatments, correctly developing food safety through the production of non-toxic nanoparticles, low-cost industrial scale-up and the use of biodegradable materials. Polysaccharide-based nanoparticles have a wide range of uses in agriculture: they improve crop yields, encourage "eco-friendly" farming methods and can decrease the concentrations of active ingredient used, providing an accurate and affective dosage without damaging further species, as well as avoiding treatment resistance risks. These nanoparticles can also reduce the negative effects of chemical fertilizers and pesticides, contributing to the environmentally friendly agricultural development. Furthermore, the application of polysaccharide-based nanoparticles is consistent with the expanding trend of green and sustainable agriculture.

Fungus-based bioherbicides on circular economy

This review aimed to show that bioherbicides are possible in organic agriculture as natural compounds from fungi and metabolites produced by them. It is discussed that new formulations must be developed to improve field stability and enable the commercialization of microbial herbicides. Due to these bottlenecks, it is crucial to advance the bioprocesses behind the formulation and fermentation of bio-based herbicides, scaling up, strategies for field application, and the potential of bioherbicides in the global market. In this sense, it proposed insights for modern agriculture based on sustainable development and circular economy, precisely the formulation, scale-up, and field application of microbial bioherbicides.

Plant Essential Oils as Biopesticides: Applications, Mechanisms, Innovations, and Constraints

The advent of the "Green Revolution" was a great success in significantly increasing crop productivity. However, it involved high ecological costs in terms of excessive use of synthetic agrochemicals, raising concerns about agricultural sustainability. Indiscriminate use of synthetic pesticides resulted in environmental degradation, the development of pest resistance, and possible dangers to a variety of nontarget species (including plants, animals, and humans). Thus, a sustainable approach necessitates the exploration of viable ecofriendly alternatives. Plant-based biopesticides are attracting considerable attention in this context due to their target specificity, ecofriendliness, biodegradability, and safety for humans and other life forms. Among all the relevant biopesticides, plant essential oils (PEOs) or their active components are being widely explored against weeds, pests, and microorganisms. This review aims to collate the information related to the expansion and advancement in research and technology on the applications of PEOs as biopesticides. An insight into the mechanism of action of PEO-based bioherbicides, bioinsecticides, and biofungicides is also provided. With the aid of bibliometric analysis, it was found that ~75% of the documents on PEOs having biopesticidal potential were published in the last five years, with an annual growth rate of 20.51% and a citation per document of 20.91. Research on the biopesticidal properties of PEOs is receiving adequate attention from European (Italy and Spain), Asian (China, India, Iran, and Saudi Arabia), and American (Argentina, Brazil, and the United States of America) nations. Despite the increasing biopesticidal applications of PEOs and their widespread acceptance by governments, they face many challenges due to their inherent nature (lipophilicity and high volatility), production costs, and manufacturing constraints. To overcome these limitations, the incorporation of emerging innovations like the nanoencapsulation of PEOs, bioinformatics, and RNA-Seq in biopesticide development has been proposed. With these novel technological interventions, PEO-based biopesticides have the potential to be used for sustainable pest management in the future.

Effects of summer savory (Satureja hortensis L.) and sweet corn (Zea mays L. saccharata) intercropping on crop production and essential oil profiles of summer savory

A 2-year field experiment evaluated the effects of sweet corn-summer savory intercropping on crop productivity and essential oil (EO) composition of summer savory. Five cropping patterns of Corn 100%:Savory 0%, C75:S25, C50:S50, C25:S75, and C0:S100 were tested. The highest corn yield (2,440 kg ha^-1) was obtained in a corn monoculture, but was not significantly different from C75:S25 or C50:S50. However, in both years the highest savory yield was obtained in S100 (793.3 g m^-2 and 816.6 g m^-2, respectively). Savory yields decreased as the proportion of corn increased. The land equivalent ratios in C25:S75, C50:S50, and C75:S25 were 1.54 ± 0.07, 1.56 ± 0.03, and 1.35 ± 0.1, respectively. Monocropped savory had the highest EO value followed by C25:S75 and C50:C50. However, no significant differences were found among these three treatments. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the major components were carvacrol (35.88%-42.96%), γ-terpinene (18.45%-20.03%), ρ-cymene (11.77%-12.24%), and α-terpinene (2.75%-3.96%). The highest amount of carvacrol was recorded in C25:S75 (42.96%). This study suggests that intercropping of corn and savory represents an effective sustainable strategy, especially for smallholders, as a way to increase their overall land productivity and to improve the quality of savory's EO.

Encapsulation of Bioactive Compounds for Food and Agricultural Applications

This review presents an updated scenario of findings and evolutions of encapsulation of bioactive compounds for food and agricultural applications. Many polymers have been reported as encapsulated agents, such as sodium alginate, gum Arabic, chitosan, cellulose and carboxymethylcellulose, pectin, Shellac, xanthan gum, zein, pullulan, maltodextrin, whey protein, galactomannan, modified starch, polycaprolactone, and sodium caseinate. The main encapsulation methods investigated in the study include both physical and chemical ones, such as freeze-drying, spray-drying, extrusion, coacervation, complexation, and supercritical anti-solvent drying. Consequently, in the food area, bioactive peptides, vitamins, essential oils, caffeine, plant extracts, fatty acids, flavonoids, carotenoids, and terpenes are the main compounds encapsulated. In the agricultural area, essential oils, lipids, phytotoxins, medicines, vaccines, hemoglobin, and microbial metabolites are the main compounds encapsulated. Most scientific investigations have one or more objectives, such as to improve the stability of formulated systems, increase the release time, retain and protect active properties, reduce lipid oxidation, maintain organoleptic properties, and present bioactivities even in extreme thermal, radiation, and pH conditions. Considering the increasing worldwide interest for biomolecules in modern and sustainable agriculture, encapsulation can be efficient for the formulation of biofungicides, biopesticides, bioherbicides, and biofertilizers. With this review, it is inferred that the current scenario indicates evolutions in the production methods by increasing the scales and the techno-economic feasibilities. The Technology Readiness Level (TRL) for most of the encapsulation methods is going beyond TRL 6, in which the knowledge gathered allows for having a functional prototype or a representative model of the encapsulation technologies presented in this review.

Microencapsulation of High-Content Actives Using Biodegradable Silk Materials

There is a compelling need across several industries to substitute non-degradable, intentionally added microplastics with biodegradable alternatives. Nonetheless, stringent performance criteria in actives' controlled release and manufacturing at scale of emerging materials hinder the replacement of polymers used for microplastics fabrication with circular ones. Here, the authors demonstrate that active microencapsulation in a structural protein such as silk fibroin can be achieved by modulating protein protonation and chain relaxation at the point of material assembly. Silk fibroin micelles' size is tuned from several to hundreds of nanometers, enabling the manufacturing-by retrofitting spray drying and spray freeze drying techniques-of microcapsules with tunable morphology and structure, that is, hollow-spongy, hollow-smooth, hollow crumpled matrices, and hollow crumpled multi-domain. Microcapsules degradation kinetics and sustained release of soluble and insoluble payloads typically used in cosmetic and agriculture applications are controlled by modulating fibroin's beta-sheet content from 20% to near 40%. Ultraviolet-visible studies indicate that burst release of a commonly used herbicide (i.e., saflufenacil) significantly decreases from 25% to 0.8% via silk fibroin microencapsulation. As a proof-of-concept for agrochemicals applications, a 6-day greenhouse trial demonstrates that saflufenacil delivered on corn plants via silk microcapsules reduces crop injury when compared to the non-encapsulated version.

Eco-friendly 'ochratoxin A' control in stored licorice roots - quality assurance perspective

According to toxicity data, ochratoxin A (OTA) is the second most important mycotoxin and is produced by Aspergillus and Penicillium. As a natural antifungal agent, clove essential oil (CEO) is a substance generally recognised as safe (GRAS) and shows strong activity against fungal pathogens. Here, we aimed to investigate the control efficacy of CEO in nano-emulsions (CEN) against OTA production in licorice roots and rhizomes during storage. The experiments were performed under simulated conditions of all four seasons (i.e. Spring, Summer, Autumn and Winter). Relative humidity (RH) and temperature were simulated in desiccators along with various salt solutions in incubators. Fresh licorice roots were immersed in CEN at various concentrations (150, 300, 600, 1200 and 2400 µl/l). Before utilising the nano-emulsions, we measured their polydispersity index and mean droplet size by the dynamic light scattering (DLS) technique. Also, the chemical composition of the CEO was determined using GC and GC-MS analyses. Sampling was carried out to monitor OTA once every five days. The samples were dried immediately and analysed by high-performance liquid chromatography (HPLC). Results showed that various concentrations of CEN inhibited the growth of fungi and OTA production. The most effective CEN concentrations were 1200 and 2400 µl/l, which reduced OTA production to 19 and 20 ppb under Winter and Autumn conditions, respectively. These results suggest an effective eco-friendly method for the storage of licorice to reduce postharvest fungal decay.

Phytotoxicological effects of engineered nanoparticles: An emerging nanotoxicology

Recent innovations in the field of nanoscience and technology and its proficiency as a part of inter-disciplinary science has set an eclectic display in innumerable branches of science, a majority in aliened health science of human and agriculture. Modern agricultural practices have been shifting towards the implementation of nanotechnology-based solutions to combat various emerging problems ranging from safe delivery of nutrients to sustainable approaches for plant protection. In these processes, engineered nanoparticles (ENPs) are widely used as nanocarriers (to deliver nutrients and pesticides) due to their high permeability, efficacy, biocompatibility, and biodegradability properties. Even though the constructive nature of nanoparticles (NPs), nanomaterials (NMs), and other modified or ENPs towards sustainable development in agriculture is referenced, the darker side i.e., eco-toxicological effects is still not covered to a larger extent. The overwhelming usage of these trending NMs has led to continuous persistence in the ecosystem, and their interface with the biotic and abiotic community, degradation lanes and intervention, which might lead to certain beneficial or malefic effects. Metal oxide NPs and polymeric NPs (Alginate, chitosan, and polyethylene glycol) are the most used ENPs, which are posing the nature of beneficial as well as environmentally concerning hazardous materials depending upon their fate and persistence in the ecosystem. The cautious usage of NMs in a scientific way is most essential to harness beneficial aspects of NMs in the field of agriculture whilst minimizing the eco-toxicological effects. The current review is focused on the toxicological effects of various NMs on plant physiology and health. It details interactions of plant intracellular components between applied/persistent NMs, which have brought out drastic changes in seed germination, crop productivity, direct and indirect interaction at the enzymatic as well as nuclear levels. In conclusion, ENPs can pose as genotoxicants that may alter the plant phenotype if not administered appropriately.