Neonicotinoids represent 25% of the insecticidal market and are essential for crop production, yet traditional neonicotinoids are toxic to most pollinators, which are also essential for food production. This issue may be addressed by the use of some chiral neonicotinoid isomers, which are much less toxic. Here, we review the chiral neonicotinoids dinotefuran, sulfoxaflor, cycloxaprid, and paichongding, with focus on their chiral characteristics, configuration stability, biological activity, ecological toxicology, and environmental fate. Isomeric separation of chiral neonicotinoids can be achieved by chromatography. The dinotefuran R isomer is less toxic than the S isomer to honeybees and earthworms by a factor of 2.7-145.9, with similar control efficiency of common agricultural pests. The insecticidal activity of (5R,7S)-paichongding are up to 20.1 times higher than that of other isomers, and it is absorbed fastest by crop roots and tends to be preferentially degraded and mineralized in soils. Therefore, formulations containing R-dinotefuran or (5R,7S)-paichongding could decrease ecological damage without compromising food production. On the other hand, it has not been possible to synthesize chiral isomers of sulfoxaflor and cycloxaprid, owing to the instability of their monomers in polar solvents.

The aim of the study was to assess the impact of plant extracts from hemp inflorescences (H10-10% and H20-20%), as well as a mixture of extracts from hemp inflorescences, sage, and tansy leaves (M10-10% and M20-20%) on phytotoxicity and selected physiological and biometric parameters of wheat seedlings, as well as the biological activity of soil in a growth chamber experiment. In all experimental combinations, a low phytotoxicity of the extracts was observed in the form of leaf tip yellowing, classified as first-degree damage or its complete absence. The plant extracts and their mixtures, except for the H20 extract, had an inhibitory effect on the development of fungal pathogens, especially Fusarium spp. The H20 extract increased the fresh and dry weight of root seedlings. The tested extracts also had a positive effect on the chlorophyll content in seedlings. The highest chlorophyll concentrations were recorded for the seedlings sprayed with the M20 extract mixture. The applied plant extracts influenced the activity of soil enzymes. The highest activity of catalase and dehydrogenases was observed after spraying seedlings with M20, while the lowest was recorded after applying H10. Of all the tested groups of soil environment compounds included in the Biolog EcoPlates test, carbohydrates and carboxylic acids were most actively utilized. Conversely, amines and amides constituted the group of compounds utilized the least frequently. The present study demonstrated the high effectiveness of plant extracts on wheat seedlings due to their biocidal action against phytopathogenic fungi and increased biological activity of the soil. This research serves as an initial phase of work, which will aim to verify the results obtained under field conditions, as well as assess the biological stability of the extracts.

Studying the impact of residual soil nanomaterials is a promising challenge for sustainable agricultural development to improve soil health and crop productivity. The objective of this study is to assess the long-term impacts of 50, 100, and 250 mg kg-1 soil of nanobiochar (nB) and nano-water treatment residues (nWTR) on the fertility, biological activity, and yield of maize (Zea mays L.) growing in heavy metal-contaminated soils. The results showed that when nB and nWTR were added in larger quantities, the concentrations of lead (Pb), nickel (Ni), cadmium (Cd), and cobalt (Co) extracted with DTPA decreased. With the addition of nB or nWTR, it also showed a significant increase in exchangeable cations, cation exchange capacity (CEC), soil fertility, soil organic matter (OM), microbial biomass carbon (MBC), and a decrease in soil salinity and sodicity. Catalase and dehydrogenase activities rose as nB addition increased, while they decreased when nWTR addition increased. In comparison to the control, the addition of nB and nWTR greatly boosted maize yield by 54.5-61.4% and 61.9-71.4%, respectively. These findings suggest that the researched nanomaterials' residual effect provides an eco-friendly farming method to enhance the qualities of damaged soils and boost maize production. Our research suggested that adding recycling waste in the form of nanoparticles could immobilize heavy metals, improve soil characteristics, and increase the soil's capacity for productivity.

Chlorine is an essential nutrient, a deficiency of which reduces plant productivity. Chlorine-containing substances have been known and used for a long time. The most common chlorine compound, sodium chloride (table salt), has been in use since ancient times. It was used as early as 3000 BC and brine as early as 6000 BC. Cl substances are mentioned in ancient texts from different cultures. The discovery of chlorine was in 1774 by Carl Wilhelm Scheele. He obtained it by reacting pyrolusite (manganese dioxide, MnO2) with hydrochloric acid (HCl, then known as muriatic acid). Scheele thought that the gas produced contained oxygen. It was Sir Humphry Davy's proposal and confirmation in 1810 that chlorine was an element, and he also named the element. Chlorine has been considered a biologically important element almost since its discovery. Research into the effects of chloride fertilisers was carried out in the second half of the last century. In 1949, Warburg argued that chloride was an important trace element for plant growth and showed that it was necessary for the water distribution system at the site of photosystem II oxidation. In the 1954 Broyer et al. finally demonstrated the biological importance of chlorine for plants. Chloride is the most abundant inorganic anion in plant cells, an element available in most agrophytocenoses. The average Cl- content in plants ranges from 2.0-20.0 mg/g DM, but for Cl-sensitive and Cl-tolerant glycophyte species, the critical (often toxic) Cl-content in tissues can be around 4-7 and 15-35 mg/g DM, respectively. Chlorine deficiency in plants has characteristic symptoms: wilting, numerous spots, and reduced productivity. Chloride performs a wide range of functions in plants, primarily forming turgor and osmoregulation, respectively, affecting transport processes on membranes (plasmalemma, tonoplast, etc.), water & nitrogen use efficiency (WUE & NUE), and affects the functioning of photosystem II, and is therefore an important part of agricultural plant productivity. Chloride stimulates the structural and functional role of the plasma membrane, sugar transport, as well as nitrogen fixation and assimilation in the plant. Nitrogen assimilation, and photorespiration become more efficient when fed with chloride. Recent studies have discussed the role of chlorine in nitrogen assimilation and photorespiration. It has been shown that Cl plays an important role in the oxygen-evolving complex by adjusting the affinity of different amino acid residues for manganese (Mn). Chlorine acts as a counterion, balancing the positive charges of potassium (K+) and other cations in plantcells,which is essential for maintaining electrical neutrality and proper ionic balance in cells. Chlorine plays a significant role in soil salinity. Sources of chlorine in soil include mineral weathering, chlorine from marine species and anthropogenic pollution. Fertilisers such as potassium chloride help to increase the chloride content of the soil. Planting salt-tolerant crops can help maintain agricultural productivity on saline soils. The sensitivity of crops to chlorine varies according to the type of crop. Some crops can tolerate higher levels of chloride without adverse effects, while others are more sensitive and may show symptoms of toxicity or growth retardation when exposed to higher chloride concentrations. Understanding the response of specific crops to chloride is important for the development of nutrient systems and irrigation practices. Chloride increases plant resistance to diseases that require relatively large amounts of Cl-. These doses are much higher than those required for its use as a trace element, but much lower than those required to induce salinity control effects. Most of the research on chlorine nutrition has been devoted to studying the effect of the element on the incidence of physiological leaf spot (PLS) in cereals. PLS form on the leaves of cereal crops when there is a lack of chlorine in the nutritional systems. The necrosis that develops in Cl-deficient plants is thought to be associated with the accumulation of H2O2 during the release of Cl from the Mn cluster of the oxygen-evolving complex. Physiological spotting in the form of completely/partially transparent dots/spots on the leaf was observed, which may indicate inhibition of chlorophyll synthesis rather than degradation. Given that chlorine at micromolar concentrations affects transport processes on membranes and that the element is easily leached through the soil profile, its deficiency occurs in the second half of the growing season, during the period of generative development, which may be the initial mechanism for the formation of PLS in the form of transparent/translucent leaf spots. The development of these spots in the generative period of development, during grain filling, can be significantly accelerated by high levels of actinic light and, accordingly, significantly limit the productivity of cereal crops and their quality. A possible component of chlorine deficiency and leaf damage in wheat and other cereals by PLS may be the application of phosphate fertilizers with high fluoride content, such as phosphate rock, etc. Therefore, in high productivity technologies, it is advisable to use phosphate fertilizers with a low fluoride content, such as potassium monophosphate. Therefore, the use of chlorine fertilisers, mainly potassium chloride in the basic application, ammonium chloride, calcium chloride, etc. in the foliar application, is important to provide plants with chlorine during the growing season to increase WUE & NUE, increase plant resistance to pathogens, control PLS, and increase productivity of cereals and other agricultural crops. Chlorine's role in increasing WUE & NUE is particularly important for the country's profitable crop production in the face of resource shortages.