Search Results (129)

Early and non-destructive detection of plant-parasitic nematodes is critical for implementing site-specific management in coffee production systems. This study evaluated the potential of unmanned aerial vehicle (UAV) multispectral and thermal imaging, combined with textural analysis, to detect Meloidogyne exigua infestation in Coffea arabica (Topázio variety). Field surveys were conducted in two contrasting seasons (dry and rainy), and nematode incidence was identified and quantified by counting root galls. Vegetation indices (NDVI, GNDVI, NGRDI, NDRE, OSAVI), individual spectral bands, canopy temperature, and Haralick texture features were extracted from UAV-derived imagery and correlated with gall counts. Under the conditions of this experiment, strong correlations were observed between gall number and the red spectral band in both seasons (R > 0.60), while GNDVI (dry season) and NGRDI (rainy season) showed strong negative correlations with gall density. Thermal imaging revealed moderate positive correlations with infestation levels during the dry season, indicating potential for early stress detection when foliar symptoms were absent. Texture metrics from the red and green bands further improved detection capacity, particularly with a 3 × 3 pixel window at 135°. These results demonstrate that UAV-based multispectral and thermal imaging, enhanced by texture analysis, can provide reliable early indicators of nematode infestation in coffee. Full article

Large-scale wireless sensor networks with electric field energy harvesters (EFEHs) offer self-powered, eco-friendly, and scalable crop monitoring in hydroponic greenhouses. However, their practical adoption is limited by the low power density of current EFEHs, which restricts the reliable operation of external sensors. To address this challenge, this work presents a noninvasive EFEH assembled with hydroponic leafy vegetables that harvests electric field energy and estimates plant functional traits directly from the electrical response. The device operates through electrostatic induction produced by an external alternating electric field, which induces surface charge redistribution on the leaf. These charges are conducted through an external load, generating an AC voltage whose amplitude depends on the dielectric properties of the leaf. A low-voltage prototype was designed, built, and evaluated under controlled electric field conditions. Two representative species, Beta vulgaris (chard) and Lactuca sativa (lettuce), were electrically characterized by measuring the open-circuit voltage (VOC) and short-circuit current (ISC) of EFEHs. Three regression models were developed to determine the relationship between foliar moisture content (FMC) and fresh mass with electrical parameters. Empirical results disclose that the plant functional traits are critical predictors of the electrical output of EFEHs, achieving coefficients of determination of $R^2=0.697$ and $R^2=0.794$ for each species, respectively. These findings demonstrate that EFEHs can serve as self-powered, noninvasive indicators of plant physiological state in living leafy vegetable crops. Full article

Stem hollowness is a common disorder in broccoli, often reducing marketable yield. This study analyzed factors influencing its development and identified agronomic strategies for mitigation. Three field trials with the varieties ‘Parthenon’ and ‘Naxos’ investigated the effects of plant density, soil mineral nitrogen supply, and foliar boron application on plant growth, head characteristics, and hollow stem development. The proportion and severity of hollow stems were significantly affected by variety, plant density, and nitrogen supply. Increasing plant density markedly reduced the disorder, with symptoms nearly absent at close spacing. ‘Parthenon’ showed high susceptibility at wide spacing, showing 30–70% incidence depending on nitrogen supply, whereas ‘Naxos’ exhibit only 1–28%. Foliar boron application had no effect. The cavity formation correlated closely with head traits and varied with cultivation and weather conditions. Hardly any hollow stems occurred at stem diameters below 3.3–4.4 cm and head weights below 330–447 g. Above these values, the severity of damage increased linearly with increasing stem diameter (R² = 0.78–0.93) and head weight (R² = 0.74–0.84). Vegetative growth had only a minor influence. Overall, stem hollowness is mainly linked to head traits, with variety and plant density being the most effective factors for its reduction. Full article

The aim of this study was to evaluate the effect of foliar application of selected micro-nutrients on the chemical composition and malting quality of spring barley (Hordeum vulgare L.). The scientific literature lacks in-depth studies that assess the effect of foliar application of micronutrients on barley malting quality. Most studies (especially under field conditions) focus on nitrogen fertilization rather than individual micronutrients. Three brewing-type barley cultivars (Baryłka, KWS Irina, and RGT Planet) were evaluated under foliar micronutrient fertilization (Cu, Mn, Mo, Zn). Fertilizers were applied at doses of 2 L ha⁻¹ for Cu, Mn, and Zn and 1 L ha⁻¹ for Mo. The experiment examined the hectoliter mass, theoretical extractability, contents of selected micro- and macronutrients, and the protein, fat, fiber, and ash contents of the grain. Furthermore, the following characteristics of barley malt were determined, i.e., moisture, protein, extractivity, Kolbach index, and diastatic power. The results showed significant variability in grain and malt quality depending on the cultivar and year. The Baryłka cultivar was characterized by the highest grain density (66.3 kg hL⁻¹) and protein content (10.9% d.m.), while RGT Planet had the highest extractivity and the most favorable malting profile. Foliar supplementation had a slightly positive effect on the average content of trace elements in barley. Mn application increased grain Ca content by 5.6% compared with the control, while foliar Zn fertilization resulted in the highest zinc concentration (a 24.7% increase). No significant effect of fertilization on malt quality was observed, but a significant interaction of experimental factors in extractivity, Kolbach index, and diastatic power was noted. The obtained results indicate that a single foliar application of microelements affects the contents of minerals and protein in the grain, but it does not lead to a significant improvement in malting parameters. This suggests the need for further research on dosage, application date, and interactions between the cultivar and environmental conditions. Full article

Atmospheric deposition is considered a source of heavy metals in plants. However, research on the uptake pathways of atmospheric particulate matter by leaves and the subsequent translocation of heavy metals within plants remains limited. In this study, the foliar uptake and translocation of heavy metals in two maize cultivars (fresh corn and silage corn cultivars, called Baiyunuo909 and Qingzhu932, respectively) were investigated through foliar exposure using soil from a mining area to simulate dry deposition under controlled chamber conditions. The height and biomass of maize were inhibited after three and five exposures to fallout deposition, and this inhibitory effect became increasingly pronounced with prolonged exposure. Furthermore, the activities of catalase (CAT) and superoxide dismutase (SOD), along with the malondialdehyde (MDA) content, significantly decreased in both cultivars relative to the control. This decrease was more significant in fresh maize, with the reduction ranges being 94.3%, 42.1%, and 40.8%, respectively. Fallout exposure elevated the contents of cadmium, lead, arsenic and zinc in the leaves, stems, and sheaths of both cultivars, despite no significant increase in the roots. The bioconcentration factors of leaves for heavy metals ranged from 0.0002 to 0.0007, representing a 3.5–fold variation; however, the overall low values showed no significant differences. Scanning electron microscopy with energy-dispersive spectroscopy revealed the accumulation of particulate matter on the leaf surface, with a higher density around the cuticle and stomata. Additionally, the fresh corn cultivar demonstrated greater sensitivity to fallout than the silage corn cultivar. In summary, heavy metals present in atmospheric particulate matter can be absorbed by leaves and subsequently translocated to other plant tissues. This study provides a theoretical foundation for understanding the mechanisms of foliar heavy metal uptake in maize. Full article

Banana (Musa spp.) is an important fruit production in Brazil, but crop productivity is still too low. The ‘Nanica’ cultivar and fertigation have been introduced, but more accurate guidelines are needed to support fertilization decisions at the orchard scale. This study aimed to develop customized nutrient standards for fertigated ‘Nanica’. A commercial ‘Nanica’ orchard provided 129 observations on yield and foliar nutrient concentrations from 2010 to 2017 in eight groves of 3.26 ha each. Plant density averaged 1479 plants ha⁻¹. The diagnostic leaf was analyzed for 13 elements. Concentration values were transformed into centered log ratios (clr), weighted log ratios (wlr), and isometric log ratios (ilr) to account for nutrient interactions and normalize the data. Yield cutoff between low- and high yielders was set at 27 t ha⁻¹ semester⁻¹. The XGBoost classification models relating yield to tissue composition returned an area under curve averaging 0.715 for log ratio expressions. Nutrient standards were expressed as clr, wlr, and raw concentration means and standard deviations of performing specimens. The clr and wlr diagnoses of a low-yielding and imbalanced specimen against a benchmark specimen (Euclidean distance = 2.5) or the performing subpopulation (Mahalanobis distance = 37.6, p < 0.01) indicated Mn shortage and Na excess. Sufficiency concentration ranges may not agree with log ratio diagnoses, especially for Mn. The clr and wlr nutrient standards were site-specific, supporting precision farming. The concept developed in this paper is applicable to endogenous research conducted by stakeholders in orchards worldwide. Full article

Experimental studies published to date on the effects of silver nanoparticles (AgNPs) on plants have yielded highly contradictory results: reported outcomes range from growth inhibition to stimulation. The objective of this research was to test the hypothesis that the ontogenetic stage at the time of exposure to AgNPs is a key determinant of both the qualitative profile and quantitative magnitude of plant responses. For this purpose, laboratory seed priming and small-plot field experiments with wheat plants (Triticum aestivum L.) treated with stabilized dispersions of AgNPs at 1–100 mg∙L⁻¹ were conducted. It was shown that seed priming with low concentrations of AgNPs (1–5 mg∙L⁻¹) did not affect wheat seedling growth, whereas dispersions at ≥25 mg∙L⁻¹ suppressed development. In agreement, antioxidant enzyme activities (POD, CAT, PPO) increased at 1–5 mg·L⁻¹ and decreased at 100 mg·L⁻¹. By contrast, foliar treatments of field-grown wheat increased plant population density, plant height, spike structure metrics, and grain yield. The optimal regimen—three foliar applications at 5 mg·L⁻¹—increased grain yield by 12.1% from 5.89 t·ha⁻¹ to 6.60 t·ha⁻¹. At low doses of AgNPs, activities of peroxidase, catalase, and polyphenol oxidase in seedlings tissues increased, indicating activation of nonspecific defense mechanisms; at higher concentrations, activities of these enzymes decreased, indicating antioxidant system exhaustion and dysfunction. The findings demonstrate dose- and stage-dependent effects and corroborate the central role of the developmental stage of wheat in determining responses to AgNPs, indicating opportunities to optimize stage-aware, low-dose application regimes to enhance productivity while minimizing phytotoxic risk. Full article

Integrating optimal plant density, microbial bioinoculants, and foliar amino acid application represents a key strategy to enhance sustainable peanut production. Therefore, the objective of this research was to investigate the combined impact of plant density (P), microbial consortium (M) bioinoculants, and foliar amino acid application (A) on the morpho-physiological and agroproductive responses of peanut production. Under field conditions, the experiment was arranged in a split–split plot with four replicates. Two plant densities of 41,667 and 83,334 plants/ha were the main plots, soil inoculation with M at 0 mL m⁻², 100 mL m⁻², and 200 mL m⁻² were the subplots, and the foliar application of VIUSID^® agro at 0 mL L⁻¹, 0.60 mL L⁻¹, and 1.20 mL L⁻¹ were the sub-subplots. Results indicated that peanut plant cultivated at a density of 83,334 plants/ha, inoculated with 100 mL m⁻² of microbial consortium, and supplemented 0.60 mL L⁻¹ of amino acid significantly enhanced the growth and physiological responses and increased peanut yield in a sustainable manner. Therefore, the findings of this study suggest that this integrated approach improved resource utilization, promoted balanced vegetative and reproductive development, and strengthened stress resilience, ultimately leading to higher productivity under sustainable management practices. Full article

Sprayers for vineyards with solution recovery represent an important innovation, offering several advantages, the most important being the efficient use of pesticides and environmental protection. This paper presents the experimental equipment designed to study the treatment process of grapevine foliage, the applied research methods, and the results of optimizing key technological parameters (hydraulic pressure p of the working solution, speed V of the airflow at the nozzle outlet) and design parameters (surface area S of the central orifice of the diffuser) in different growth stages of grapevines with varying foliar density ρ, the response function being the recovery rate of the working solution. The construction of the SVE 1500 (Experimental model, manufactured at the Institute of Agricultural Technology “Mecagro”, Chisinau, Republic of Moldova) vineyard sprayer with solution recovery is presented, along with test results obtained in field conditions, which demonstrated that the experimental model of our machine ensures a 38% reduction in working solution consumption during the active vegetation phase while maintaining treatment quality in compliance with agrotechnical requirements. The SVE 1500 machine can be towed with a sufficient turning radius for use in modern vineyard plantations. Construction documentation has been developed for the production and delivery of the experimental batch of SVE 1500 machines to agricultural enterprises. Full article

Improving rice yield, eating quality, and zinc (Zn) nutrition is crucial to meet the growing demand for high-quality and nutritious food, while zinc itself plays a pivotal role in rice growth and quality formation. In this two-year field study, we investigated the effects of zinc oxide nanoparticles (ZnO NPs) one-time foliar application at 5, 10, and 20 mg L⁻¹ during the gestation stage on grain yield, rice quality, and zinc biofortification. Although some year-to-year variations and year × treatment interaction in the magnitude of these effects were observed, the positive responses to ZnO NPs were consistent across the two years. Results showed that ZnO NPs application increased grain yield by 1.40–4.62%, mainly supported by enhanced net photosynthetic rate and SPAD values after heading. Meanwhile, ZnO NPs significantly enhanced taste value (1.61–7.22%) and breakdown value (5.36–15.63%), while reducing chalkiness rate (5.73–18.62%), chalkiness degree (11.57–27.18%), amylose content (3.72–6.76%), and setback value (8.98–24.53%). Additionally, ZnO NPs markedly increased the zinc content (23.73–85.10% in brown rice; 29.07–103.07% in polished rice) and reduced the phytic acid to zinc molar ratio by 18.46–48.39%, improving zinc enrichment and bioavailability. These findings suggest that ZnO NPs foliar application is effective to simultaneously enhance grain productivity, rice quality, and zinc density. Full article

Plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for enhancing crop productivity and suppressing phytopathogens. In this study, seven bacterial isolates obtained from the rhizosphere of healthy tomato plants were evaluated for their antagonistic activity against the fungal pathogen Passalora fulva, the leaf miner Tuta absoluta, and their effects on tomato growth. In vitro dual-culture assays revealed that isolates IQR1, IQR2, IQR3, and IQR5 significantly inhibited P. fulva mycelial growth, with inhibition rates exceeding 35%. Volatile organic compounds (VOCs) produced by the bacterial isolates exhibited considerable antifungal activity, with IQR5, IQR1, and IQR2 achieving over 84% inhibition. Molecular identification based on 16S rDNA sequencing indicated that these isolates belong to distinct taxa: Leucobacter aridicolis (ON799334.1) (genus Leucobacter), Paenochrobactrum sp. (JF804769.1) (genus Paenochrobactrum), an uncultured bacterium (JQ337400.1) (genus Psychrobacter), and marine bacterium AK6_052 (KF816539.1) (genus Brevundimonas). Under greenhouse conditions, isolates IQR3, IQR5, and IQR1 reduced disease incidence of P. fulva to 20–26%. The same isolates also promoted plant growth, enhancing stem height and collar diameter. In addition, IQR5 significantly reduced T. absoluta larval density and foliar damage, with the number of larvae per leaflet decreasing to 1.42, compared to 3.20 in the control. These findings highlight the potentials of these rhizobacterial strains—particularly IQR5—as effective biocontrol agents and biofertilizers for integrated pest and disease management in tomato cultivation. Full article

To reveal the effects of genotype–herbivore interactions on leaf quality, foliar variations in phytochemicals, morphoanatomy, and herbivory damage ratio were investigated in a Cyclocarya paliurus (Batalin) Iljinsk. (Juglandaceae) germplasm resources bank. Results showed less herbivory damage in genotypes with a higher leaf thickness, but more herbivory damage in genotypes with a higher leaf stomatal density. Herbivory damage ratios were significantly correlated with the contents of leaf secondary metabolites, whereas the response of secondary metabolites to insect attack was type-specific and varied between intact leaves and damaged leaves. Based on key indicators of leaf quality (contents of triterpenoids, flavonoids, polyphenols, pterocaryoside A, pterocaryoside B, and cyclocaric acid B), the investigated genotypes were divided into three distinct groups by integrating TOPSIS and cluster analysis, while four genotypes with slight insect damage demonstrated the prioritization for future applications. Our findings lay a foundation for further selection of its superior varieties with both insect resistance and high leaf quality. Full article

Urbanization profoundly alters environmental conditions (e.g., temperature, artificial light at night (ALAN), and precipitation) that strongly influence vegetation phenology. However, the rate and extent of vegetation phenological responses to urbanization, as well as their underlying mechanisms, remain underexplored, particularly the roles of CO₂ emissions and PM₂.₅ concentrations, as well as the interactions among environmental conditions. We first used road network density (RND) to represent urbanization effects and quantified the phenological response rate and extent across 31 cities in China (2014–2022) using slope and range metrics derived from linear regressions of phenostages (start of season (SOS), end of season (EOS), length of season (LOS)) against RND. Partial least squares structural equation modeling was applied to assess the direct and indirect effects of RND on phenology via all five key environmental factors. Our results identified substantial differences in the urban phenological responses across latitudinal, hydrothermal, and land−cover gradients. And the impact of urbanization on phenology was most pronounced during early expansion (at a RND threshold of 2.02 ± 0.41 km/km²) but diminished with continued growth. Environmental factors distinctly affected phenological response rate and extent through RND; temperature, ALAN, and CO₂ emissions were the dominant drivers of slope, negatively affecting SOS (β = −0.37 to −0.69) but positively affecting EOS and LOS (β = 0.31 to 0.68). PM₂.₅ played a crucial role in determining the range of SOS (β = −0.31), and precipitation had the largest impact on the range of EOS (β = −0.37). Our study innovatively uses RND to quantify urbanization intensity and improve understanding of the combined effects of multiple drivers, especially PM₂.₅ and CO₂, on phenological responses, which may offer a useful reference for future urban planning strategies that aim to balance development with ecosystem functioning. Full article

Although the allocation of biomass among floral organs reflects critical trade-offs in plant reproductive strategies, the scaling relationships governing biomass allocations remain poorly resolved, particularly in flowers. Here, we report the fresh mass scaling allocation patterns among four floral organs (i.e., sepals, petals, stamens, and carpels), and the two subtending structural components (i.e., the pedicel and receptacle) of 497 flowers of the hypogynous Rosa chinensis var. minima (miniature rose) using reduced major axis protocols. The two-parameter Weibull probability density function was also applied to characterize the distributions of floral organ mass, and revealed skewed tendencies in all six measured traits. The results show that the numerical values of the scaling exponents (α) for all pairwise power-law relationships significantly exceeded unity (α > 1), indicating disproportionate investments in larger floral structures with increasing overall flower size. Specifically, the scaling exponent of corolla fresh mass vs. calyx fresh mass was α = 1.131 (95% confidence interval [CI]: 1.086, 1.175), indicating that petal investment outpaces sepal investment as flower size increases. Reproductive organs also exhibited significant disproportionate investments (i.e., allometry): the collective carpel (gynoecium) fresh mass scaled allometrically with respect to the collective stamen (androecium) mass (α = 1.062, CI: 1.028, 1.098). Subtending axial structures (pedicel and receptacle) also had hyperallometric patterns, with pedicel mass scaling at α = 1.167 (CI: 1.106, 1.235) with respect to receptacle mass. Likewise, the combined fresh mass of all four foliar homologues (sepals, petals, androecium, and gynoecium) scaled disproportionately with respect to the biomass of the two subtending axial structures (α = 1.169, CI: 1.126, 1.214), indicating a prioritized resource allocation to reproductive and display organs. These findings are in accord with hypotheses positing that floral display traits, such as corolla size, primarily enhance pollen export by attracting pollinators, while maintaining fruit setting success through coordinated investment in gynoecium development. The consistent hyperallometry across all organ pairwise comparisons underscores the role of developmental integration in shaping floral architecture in Rosaceae, as predicted by scaling theory. By integrating morphometric and scaling analyses, this study proposes a tractable methodology for investigating floral resource allocation in monomorphic-flowering species and provides empirical evidence consistent with the adaptive patterns of floral traits within this ecologically and horticulturally significant lineage. Full article

Disease resistance is one of the most important target traits for sugarcane genetic improvement. Sugarcane brown stripe (SBS) caused by Helminthosporium stenospilum is one of the most destructive foliar diseases, which not only reduces harvest cane yield but also sugar content. This study aimed to identify quantitative trait loci (QTL) and candidate genes associated with SBS resistance. Here, the phenotypic investigation in six field habitats showed a continuous normal distribution, revealing that the SBS resistance trait is a quantitative trait. Two high-density linkage maps based on the single-dose markers calling from the Axiom Sugarcane100K SNP chip were constructed for the dominant sugarcane cultivars YT93-159 (SBS-resistant) and ROC22 (SBS-susceptible) with a density of 2.53 cM and 2.54 cM per SNP marker, and mapped on 87 linkage groups (LGs) and 80 LGs covering 3069.45 cM and 1490.34 cM of genetic distance, respectively. A total of 32 QTL associated with SBS resistance were detected by QTL mapping, which explained 3.73–11.64% of the phenotypic variation, and the total phenotypic variance explained (PVE) in YT93-159 and ROC22 was 107.44% and 79.09%, respectively. Among these QTL, four repeatedly detected QTL (qSBS-Y38-1, qSBS-Y38-2, qSBS-R8, and qSBS-R46) were considered stable QTL. Meanwhile, two major QTL, qSBS-Y38 and qSBS-R46, could account for 11.47% and 11.64% of the PVE, respectively. Twenty-five disease resistance candidate genes were screened by searching these four stable QTL regions in their corresponding intervals, of which Soffic.01G0010840-3C (PR3) and Soffic.09G0017520-1P (DND2) were significantly up-regulated in YT93-159 by qRT-PCR, while Soffic.01G0040620-1P (EDR2) was significantly up-regulated in ROC22. These results will provide valuable insights for future studies on sugarcane breeding in combating this disease. Full article