Nanotechnology is rapidly emerging as a transformative force in agriculture, offering innovative solutions to support sustainable crop production. This review examines the interactions between nanoparticles (NPs) and plants, elucidating the underlying mechanisms that govern NP uptake, translocation, and interactions at the cellular level. We explore how NPs influence key physiological processes and modulate plant defense responses to both biotic and abiotic stresses, highlighting their potential for enhancing stress resistance. The diverse applications of NPs in agriculture are also comprehensively surveyed, encompassing targeted delivery of nutrients, enhanced biocontrol of phytopathogens, and engineering improved tolerance to environmental extremes. We also address the broader environmental and socioeconomic implications of the widespread use of NPs in agriculture, critically evaluating their ecotoxicity, impacts on biodiversity, and the associated economic costs and benefits. Finally, we offer a perspective on future directions for research, including emerging trends in NPs synthesis and characterization, challenges to sustainable implementation, and the prospects for large-scale deployment of nanotechnology-enabled agricultural solutions. This review provides a rigorous and balanced assessment of the potential of nanotechnology to revolutionize agricultural practices while acknowledging the need for responsible innovation and risk mitigation.

In order to investigate the potential of various olive cultivars and leaf sampling times for phytochemical farming practice in Croatia, phenolic and mineral composition was determined in olive leaves of four Croatian cultivars and Italian cultivar Leccino collected at three occasions, in October 2017, January 2018, and March 2018. Istarska bjelica turned out to have the largest phytochemical potential among the investigated cultivars due to steady high oleuropein concentrations found in its leaves. The concentration of main phenolic components in Istarska bjelica leaves changed only slightly during the sampling period, suggesting the possibility of its higher capability for low air temperatures stress resistance and different metabolic response compared to the other studied cultivars. Low air temperatures increased the oleuropein level and antioxidant activity in leaves of Leccino, Oblica, Levantinka, and Drobnica cultivars, which may be of crucial phytochemical farming interest. Each of the investigated olive cultivars was characterized by a specific leaf mineral nutrient composition, which could have had a specific role in their interplay with phenols.

The interactive effects of cultivar, collecting period, and geographical location on the content and composition of biophenols and macro and micronutrients in olive (Olea europaea L.) leaf were investigated. Leaves of six cultivars were collected at three periods in two locations in Croatia. The leaves of Istarska bjelica cultivar had the greatest biophenol (oleuropein) potential, especially those sampled in January and in March at the location of Pag. All the cultivars yielded leaves with the highest concentration of biophenols in March, which coincided with the pruning period. Except for high oleuropein concentration in Istarska bjelica, flavonoids were found to be most useful for differentiating olive leaves according to cultivar. Verbascoside turned out to be the most potent differentiator of collecting periods, while phosphorus and zinc turned out to be most useful for differentiating locations. Despite different agroecological conditions at the two locations, cultivar exhibited a significant effect on olive leaf nutrient composition, which was certainly causally related to that of the biophenols. The results obtained showed that it is possible to plan more well-timed and efficient exploitation of biophenols from olive leaf based on the knowledge about the interactive effects of the three studied factors.

Plant-based fertilizers, such as liquid plant extracts, contribute to the cultivation of vegetables, particularly in organic production. The objective of this study was to determine if aqueous nettle extract could be successfully used as a fertilizer, applied on the soil and foliarly, in green bean production under field conditions. The hypothesis was that it could successfully replace mineral fertilizers and be integrated into sustainable and organic agriculture. The experiment was conducted at two climatically and pedologically different locations (Zadar and Poreč) throughout two growing seasons (spring and autumn). Two types of aqueous nettle extracts were used: a short-term extract (SE) was prepared by the extraction of wild stinging nettle (183 g 10 L⁻¹ of water) in water for 24 h, while a long-term extract (LE) was prepared at the same ratio with water extraction for 14 days. Both extracts were diluted with water at a ratio of 1:3 (extract:water) before use. The SE was applied foliarly, and LE, by pouring it onto the soil. The abovementioned treatments were compared with mineral fertilization with urea (U) and control (no fertilization (C)). Foliar fertilization with SE proved to be almost as efficient as fertilization with LE, poured onto soil, showing a positive effect on green bean vegetative parameters. Furthermore, aqueous nettle extracts showed a positive effect on the iron accumulation in the leaves.

Rising temperatures and pronounced drought are significantly affecting biodiversity worldwide and reducing yields and quality of Brassica crops. To elucidate the mechanisms of tolerance, 33 kale accessions (B. oleracea var. acephala) were evaluated for individual (osmotic and elevated temperature stress) and combined stress (osmotic + temperature). Using root growth, biomass and proline content as reliable markers, accessions were evaluated for stress responses. Four representatives were selected for further investigation (photosynthetic performance, biochemical markers, sugar content, specialized metabolites, transcription level of transcription factors NAC, HSF, DREB and expression of heat shock proteins HSP70 and HSP90): very sensitive (392), moderately sensitive (395), tolerant (404) and most tolerant (411). Accessions more tolerant to stress conditions were characterized by higher basal content of proline, total sugars, glucosinolates and higher transcription of NAC and DREB. Under all stress conditions, 392 was characterized by a significant decrease in biomass, root growth, photosynthesis performance, fructan content, especially under osmotic and combined stress, a significant increase in HSF transcription and HSP accumulation under temperature stress and a significant decrease in NAC transcription under all stresses. The most tolerant accession under all applied stresses, 411 showed the least changes in all analyzed parameters compared with the other accessions.