Search Results (42)

The intensification of olive growing has raised environmental concerns, particularly regarding nutrient loss from excessive fertiliser use. In line with the European Union’s Farm to Fork strategy, which aims to halve the soil nutrient losses by 2030, this study evaluates the effectiveness of two sensor-based approaches—proximal sensing with a FLAME spectrometer and remote sensing via UAV-mounted multispectral imaging—compared with foliar chemical analyses as the reference standard, for diagnosing the nutritional status of olive trees. The research was conducted in Elvas, Portugal, between 2022 and 2023, across three olive cultivars (‘Azeiteira’, ‘Arbequina’, and ‘Koroneiki’) subjected to different fertilisation regimes. Machine learning (ML) models showed strong correlations between sensor data and nutrient levels: the multispectral sensor performed best for phosphorus (P) (determination coefficient [$R^2$] = 0.75) and potassium (K) ($R^2$ = 0.73), while the FLAME spectrometer was more accurate for nitrogen (N) ($R^2$ = 0.64). These findings underscore the potential of sensor-based technologies for non-destructive, real-time nutrient monitoring, with each sensor offering specific strengths depending on the target nutrient. This work contributes to more sustainable and data-driven fertilisation strategies in precision agriculture. Full article

Macroalgal extracts are widely recognised as biostimulants that enhance crop productivity and plant growth under both optimal and stressful conditions. They offer a sustainable approach to mitigating the adverse effects of abiotic stress on crop development. This study investigates the efficacy of macroalgal-based fertilisers in enhancing tomato (Solanum lycopersicum L.) growth, yield, and fruit quality, as sustainable alternatives to chemical fertilisers. Different seaweed species (Sargassum muticum, Ulva ohnoi, Furcellaria lumbricalis, Ascophyllum nodosum, and a commercial A. nodosum extract) were evaluated as foliar treatments. The results showed that while the leaf fresh weight and chlorophyll content were not significantly affected, the fruit morphology and biochemical composition exhibited notable variations. Sargassum muticum-treated fruits displayed the highest °Brix (6.57), indicating superior sugar accumulation, while Ulva ohnoi maintained near-neutral pH levels (avg. 3.94), suggesting balanced acidity. Ascophyllum nodosum extracts induced the highest proline concentrations (peak: 63.77 µmol/g), but also caused extreme acidity (pH 1.39–2.58). Furcellaria lumbricalis enhanced the fruit size (axial length up to 41.4 mm), but reduced the pH sharply (1.69–2.13). The commercial product underperformed in regard to sugar content and flavour complexity. The integrative analysis revealed species-specific flavour profiles: Sargassum yielded sweet, mildly acidic fruits; Ascophyllum produced intensely aromatic, acidic tomatoes; and Ulva resulted in bland flavours. These findings underscore the importance of algal species and extraction methods in tailoring biofertilisers for target fruit qualities. This study advocates for the use of macroalgal fertilisers in sustainable agriculture, but highlights the need for optimised formulations to balance crop yield, taste, and stress adaptation. Full article

Maize, regarded as a staple economic crop, attracts special global attention with the aim to enhance its production. Foliar fertilisation offers a complementary method to traditional soil fertilisation amongst resource-limited agricultural systems, providing a more efficient solution to nutrient deficiencies, especially in suboptimal soil conditions. This study aimed to analyse foliar fertiliser formulation research directions and their application in maize production. A literature search was conducted in the Web of Science (WoS) database. Bibliometric analyses were performed using the VOSviewer software (version 1.6.17). The changes in the publication trends of documents were tested using the Mann–Kendall test. The production effects of foliar fertilisation were independently synthesised. The results showed a strong positive increase in publication trends regarding maize foliar fertilisation (R² = 0.7842). The predominant nutrients that affected maize production were nitrogen, phosphorous, potassium, zinc, iron, and manganese. The timely foliar application of nutrients corrected deficiencies and/or sustained nutrient supply under several abiotic stresses. Foliar application at critical growth stages like flowering and grain filling boosted carbohydrate and protein content, lipid levels, kernel size, mineral content, and the weight of the maize grain. This review identified important research gaps, namely genotype-specific responses, interactions with other agronomic practices, and long-term environmental effects. Full article

On commercial banana (Musa spp.) plantations, soils are often supplemented with phosphorus (P) fertiliser to optimise production. Such additions may influence the diversity and function of soil microbial communities, which play important roles in P cycling and affect plant fitness. Here, we characterised the effects of P addition on the diversity and function of banana-associated microbial communities. P addition was associated with significant increases in soil P and the activities of alpha-glucosidase, chitinase, arylsulphatase, and acid phosphatase, but not beta-glucosidase or xylosidase. P addition also expedited bunch emergence and harvest, but did not influence fruit yield, plant height, or foliar P. There were no significant effects of P addition on the alpha or beta diversity of bacterial, fungal, and nematode communities, including members of the core microbiome. The only exceptions to this was an increase in the relative abundance of a Fusarium population in roots. These results indicate that phosphorus application to banana soils may stimulate microbial enzyme activities with minor or negligible effects on microbial diversity. Full article

The main objective of this study was to compare the effectiveness of an innovative multi-nutrient fertiliser (PRO complete) applied foliarly with a standard fertiliser (TRA complete) in triticale crops. PRO complete contained macronutrients (N, P, K), micronutrients (B, Cu, Fe, Mn, Mo, Zn, with Fe and Zn complexed with amino acids), and trace elements (Cr, I, Li, Se—combined with plant extracts). TRA complete had the same quantitative composition, but the micronutrients and trace elements were in mineral form or in complex with EDTA. The experiment was conducted on triticale grown in a soil culture in a growing hall. The triticale yield and quality were determined. The fertilisers had no significant effect on straw yield and macronutrient (N, P, K, Mg, Ca) content in straw and grain. They caused a significant increase in grain yield, but PRO complete was more effective, also in terms of increasing the content of some micronutrients, particularly in straw. Both fertilisers increased the content of Cr, Li, and Se in straw. The application of the fertilisers contributed to some extent to triticale biofortification. In conclusion, the use of foliar multi-compound fertilisers is a beneficial choice for optimising crop yield and quality. However, their chemical composition and dosage should be further developed. Full article

The application of foliar fertiliser can rapidly replenish the essential nutrients required by crops. In order to enhance the precision of foliar fertiliser spraying, fertiliser utilisation, and leaf absorption efficiency, this study proposes the implementation of an efficient foliar fertiliser dual-face target precision variable spraying robot system based on computer vision. In this study, we propose the SN-YOLOX Nano-ECA as a real-time classification model for potted plants. The model has parameters and FLOPs of only 0.48 M and 0.16 G, respectively. Following deployment, the classification precision and recall reached 97.86% and 98.52%, respectively, with an FPS of 37.6. A dual-face target precision variable spraying method of foliar fertiliser based on the determination of leaf area and plant height information of potted plants was proposed. A robot platform for the application of foliar fertilisers was developed, and a positioning and navigation system based on the RSSI principle was constructed. The results of the foliar fertiliser spraying experiments demonstrate that the precision of the extracted leaf area and height information is above 97% and 96%, respectively. The navigation system demonstrated distance and angle errors of only 5.598 cm and 0.2245°. The mean discrepancy between the actual and set spraying volumes was 0.46 mL. This robotic system is capable of precise spraying of foliar fertiliser, which provides a new idea and reference for the development of efficient and precise variable spraying technology for foliar fertiliser. Full article

Waterlogging increasingly challenges crop production, affecting 10% of global arable land, necessitating the development of pragmatic strategies for mitigating the downside risk of yield penalty. Here, we conducted experiments under controlled (tank) and field conditions to evaluate the efficacy of nitrogenous fertiliser in alleviating waterlogging stress. Without intervention, we found that waterlogging reduced grain yields, spike numbers and shoot biomass, but had a de minimus impact on grain number per spike and increased grain weight. Soil fertiliser mitigated waterlogging damage, enhancing yields via increased spike numbers, with crop recovery post-waterlogging catalysed via improved tiller numbers, plant height and canopy greenness. Foliar nitrogen spray has little impact on crop recovery, possibly due to stomatal closure, while modest urea application during and after waterlogging yielded similar results to greater N application at the end of waterlogging. Waterlogging-tolerant genotypes (P-17 and P-52) showed superior growth and recovery during and after waterlogging compared to the waterlogging-sensitive genotypes (Planet and P-79). A comparison of fertiliser timing revealed that field fertilizer treatment two (F2: 90 kg·ha⁻¹ at 28 DWL, 45 kg·ha⁻¹ at sowing and 45 kg·ha⁻¹ at 30 DR) yielded the highest and fertilizer treatment three (F3: 45 kg·ha⁻¹ at sowing and 45 kg·ha⁻¹ at 30 DR) recovered the lowest yield and spike number, while fertilizer treatment one (F1: 45 kg·ha⁻¹ at 28 DWL, 45 kg·ha⁻¹ at 0 DR, 45 kg·ha⁻¹ at sowing and 45 kg·ha⁻¹ at 30 DR) and four (F4: 90 kg·ha⁻¹ at 0 DR, 45 kg·ha⁻¹ at sowing and 45 kg·ha⁻¹ at 30 DR) had the highest shoot biomass in the field. Treatment five (T5: 180 kg·ha⁻¹ at 0 DR, 30 kg·ha⁻¹ at sowing and 90 kg·ha⁻¹ at 30 DR) presented the most favourable results in the tank. Our results provide rigorous evidence that long periods of waterlogging caused significant yield penalty, mainly due to decreased spike numbers. We contend that increasing fertiliser rates during waterlogging up to 90 kg·ha⁻¹ can provoke crop growth and mitigate waterlogging-induced grain yield losses, and is more beneficial than applying nitrogen post-waterlogging. Full article

In no-till cropping systems, banding of phosphorus (P) fertiliser at seeding results in low use efficiency due to chemical reactions in soil. Foliar P has the potential to allow grain producers to respond tactically with P application after sowing when P supply from soil and fertiliser is not meeting crop demand. The objective of this study was to evaluate the effectiveness of foliar P on wheat grain yield, grain quality, biomass yield, P uptake and P use efficiency indices. Nine field experiments were conducted to investigate the response of wheat to foliar P. Three rates of P, 0, 2.5 and 5.0 kg/ha, as phosphoric acid (H₃PO₄ 85%) were applied to wheat at three different growth stages: first tiller emergence (Z21), first node detection (Z31) and flag leaf emergence (Z39). Grain yield responses ranging from 176 kg/ha to 505 kg/ha to foliar-applied P were observed in six out of nine experiments. The percent grain yield response to foliar P was negatively related to the P buffering index (PBI, 0–10 cm soil depth), which is attributed to greater sorption by soil of the foliar P at the higher PBI levels. Mean agronomic efficiency (AE) across the experiments was 111 kg/kg P but reached up to 232 kg/kg P. It was also evident that foliar P has the potential to improve P concentration in shoots and grains and increase P uptake but with no or minimal effect on grain quality. Our results suggest that a combination of tissue testing at the seedling stage and soil P buffering can be used to guide when foliar P application is likely to increase grain yield in wheat. Full article

It is not yet clear how adding silicon foliar fertilisation affects olive leaf (OL) phenolics and their potential to impact different cancer cells. Thus, we conducted a field trial to study the effect of foliar Si biostimulant fertilisation on the OL phenolic content of the ‘Leccino’ (LE) and ‘Istarska Bjelica’ (IB) cultivars. The experiment compared untreated Control (C) and three distinct levels of silicon (Si1, Si2, Si3) with Si concentrations of 0.55 g/L, 1.1 g/L, and 2.2 g/L, respectively. Si3 application resulted in the highest levels of oleuropein, apigenin-7-O-glucoside, luteolin-4-O-glucoside, rutin, and tyrosol compared to the C treatment. The polyphenols showed high cytotoxic activity in three cancer cell lines tested: cervical adenocarcinoma (HeLa), colon cancer (HCT116), and osteosarcoma (U2OS). The strongest inhibition of cell growth was observed in the HCT116 cell line. All cancer cells tested were more sensitive to treatment with polyphenols isolated from plants with added Si than those without added Si. The cytotoxic activity of the extracts on the healthy cell line RPE1 was similar to that on the cancer cell line HCT116 and U2OS. Full article

The cultivation of walnuts (Juglans regia L.) has become increasingly popular worldwide due to the nutritional value of the nuts. Plant biostimulants (PBs) and nutrient-rich products have been increasingly used in agriculture to improve yield, quality, and abiotic stress tolerance. However, farmers need fast laboratory studies to determine the most suitable treatment per crop or ecosystem to take full advantage of these products. Evaluating nucleolar activity and protein content can provide clues about the most appropriate treatment. This study aimed to determine how five commercial products, four PBs based on seaweed extract and/or free amino acids and one boron-enriched fertiliser used as foliar sprays, affect walnut cv’s nucleolar activity and protein content. “Franquette” from an orchard located in NE Portugal was compared to untreated (control) plants. All treatments brought a low leaf mitotic index. The control showed the smallest nucleolar area, highest protein content, and highest frequency of nucleolar irregularities. Fitoalgas Green^®, Sprint Plus^®, and Tradebor^® showed the highest nucleolar area and lowest frequencies of nucleolar irregularities. The recruitment of proteins/enzymes for response against abiotic stresses may explain the high protein content in the control. Hence, the enhanced abiotic stress tolerance of the treated trees explains their lower protein content and frequency of nucleolar anomalies. Globally, the Fitoalgas Green^®, Sprint Plus^®, and Tradebor^® seem better suited for “Franquette” walnut trees under the edaphoclimatic conditions where trials were conducted. Full article

A two-year trial (2021 and 2022) was performed with five different fungicide and foliar fertiliser application strategies to control apple scab (Venturia inaequalis) in integrated apple orchards in Latvia. A strategy of using inorganic fungicides or combining them with synthetic fungicides was compared to a strategy of applications with only synthetic fungicides and untreated control. Furthermore, two strategies included foliar fertilisers to determine whether they may affect apple scab used alone or combined with synthetic fungicides. The timing of the fungicide applications was based on the risk forecasted by the decision support system RIMpro, and fertilisers were used at certain growth stages of the crop. The disease incidence on untreated fruits on cv. Auksis ranged from 38.3% to 59.6%, and on cv. Ligol from 99.3% to 99.5%. Strategies including synthetic fungicides were the most effective against scab on shoot leaves and fruits. The strategy using only inorganic fungicides was effective for low-inoculum orchards. Combining synthetic and inorganic fungicides provided the best apple scab control strategy on fruits, likely helping reduce the resistance selection pressure and residues of synthetic fungicides. Foliar fertilisers were insufficient to control apple scab; they would supplement existing scab fungicide programs. Full article

Legumes, due to their symbiosis with papillary bacteria, can receive nitrogen from the air. The remaining nutrients must be supplied in fertilisers, either soil or foliar. In the pot experiment, we recorded the responses of two soybean cultivars (Annushka, Pompei) to the foliar application of micronutrients (control, Zn, Fe, Cu, Mn, B, or Mo). The physiological properties were expressed as net photosynthetic rate (P_N), intercellular CO₂ concentration (C_i), transpiration rate (E), stomatal conductance (g_s), maximum quantum yield of photosystem II (F_v/F_m), maximum quantum yield of primary photochemistry (F_v/F₀), photosynthetic performance index (PI), and the development of soil plant analyses (SPAD), which were analysed. The effects of individual micronutrients on nodulation, plant growth, and condition were also investigated. Micronutrient fertilisation had a positive effect on plant fresh weight and no negative effect on plant condition. It was shown that elements such as B, Fe, and Mo had the most beneficial effect on nodulation compared to the control, regardless of the cultivar analysed. The application of single-component foliar fertilisers improved the physiological parameters of the plants. The relative chlorophyll content was most favourably affected by the application of Mn, B, and Mo in the Annushka cultivar, and Fe, Mn, and Mo in the Pompei cultivar. Similarly, in the case of chlorophyll fluorescence, the most stimulating effect was found for Mn and B, regardless of the cultivar. In the case of gas exchange, the application of Fe, Mo, and B for the Annushka cultivar and Cu for the Pompei cultivar had the most favourable effect on physiological measurements. The results obtained indicate that the foliar application of the evaluated micronutrients is justified in soybean cultivation and does not disturb the nodulation process. Full article

The increased frequency of climate change-induced droughts poses a survival challenge for forest trees, particularly for the common beech (Fagus sylvatica L.). Drought conditions adversely affect water supply and nutrient uptake, yet there is limited understanding of the intricate interplay between nutrient availability and drought stress on the physiology, growth, and biomass accumulation in young trees. We aimed to address this knowledge gap by examining the effects of irrigation and fertilisation and their interaction with various parameters in common beech saplings, including foliar and root N, P, and K concentrations; height and diameter increments; and aboveground and belowground biomass production. Our findings revealed that a higher fertilisation dose increased nutrient availability, also partially mitigating immediate drought impacts on foliar N concentrations. Also, higher fertilisation supported the post-drought recovery of foliar phosphorus levels in saplings. Prolonged drought affected nitrogen and potassium foliar concentrations, illustrating the lasting physiological impact of drought on beech trees. While drought-stressed beech saplings exhibited reduced height increment and biomass production, increased nutrient availability positively impacted root collar diameters. These insights have potential implications for forest management practices, afforestation strategies, and our broader understanding of the ecological consequences of climate change on forests. Full article

A field experiment with winter wheat (Triticum aestivum L.) cultivation was conducted at the Research and Education Centre in Tomaszkowo, Poland (53°72′ N; 20°42′ E) in the years 2013–2016. Fertilisation with nitrogen at 150 and 200 kg ha⁻¹ and foliar application of manganese at 0.5 and 1.5 kg ha⁻¹ were the research factors. Wheat infestation by Fusarium spp. was determined by the habitat conditions during crop growth. Neither nitrogen nor manganese fertilisation affected the presence of Fusarium spp. symptoms on wheat ears, but the infestation intensity decreased with increasing nitrogen and manganese content in the grain. Only the level of deoxynivalenol (DON) was correlated with Fusarium spp. infestation. Increasing the nitrogen fertilisation rate from 150 kg ha⁻¹ to 200 kg ha⁻¹ resulted in higher grain contamination with toxins. Supplementation of nitrogen fertilisation with manganese reduced the number of mycotoxins in wheat grain. The grain yield was mainly affected by the varied weather conditions during the wheat-growing periods. Neither nitrogen nor manganese fertilisation differentiated the wheat grain yield. The objective of this study was to examine the impact of the weather conditions and nitrogen and manganese fertilisation on the grain yield, occurrence of Fusarium head blight and mycotoxin level in winter wheat grain. Full article

Micronutrients are essential to plants, and enhancing their availability is one of the agronomic challenges to improving crop quality and yield. This study, under controlled greenhouse conditions, compares tomato plants’ responses to two different micronutrient EDTA-chelated formulations, one of them including a newly developed fulvate–lignosulfonate coating. Growth, yield, and several physiological parameters, including photosynthetic gas exchange, water-use efficiency, leaf nutrient content, leaf greenness and the effective quantum yield of photosystem II, were measured to compare their efficiency. The results showed that the new coated formulation significantly improved growth and most of the determined physiological parameters. At the end of the experiment, higher foliar levels of Fe (2.4-fold) and Mn (2.9-fold) were measured, revealing increased availability of lignofulfonate-complexed micronutrients compared to the traditional fertiliser. Moreover, the photosynthesis rate and stomatal conductance were 9- and 20-fold higher, respectively, than when using the standard fertiliser. In conclusion, the new coated fulvate–lignosulfonated fertiliser provided a more suitable source of micronutrients for tomato plant fertilisation, allowing for higher yields, which correlated with a generally improved physiological response. Full article