Foliar Application Research Articles

An Innovative Approach: Alleviating Cadmium Toxicity in Grapevine Seedlings Using Smoke Solution Derived from the Burning of Vineyard Pruning Waste.

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl2 to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m-2.sn-1), and total phenolic content (1.89 mg.g-1), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g-1). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg-1), catalase (CAT) (1.55 U.mg-1), and ascorbate peroxidase (APX) (3.03 U.mg-1). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms.

Foliar application of bioorganic fertilizers enhances plant nutrients uptake and citrus yield by regulating rhizosphere and phyllosphere microbiome

Foliar application of bioorganic fertilizers enhances plant nutrients uptake and citrus yield by regulating rhizosphere and phyllosphere microbiome

Effect of foliar application of water-soluble fertilizer (NPK) with microbial consortia seed treatment on growth, yield and nutrient uptake by blackgram in Alfisols

Effect of foliar application of water-soluble fertilizer (NPK) with microbial consortia seed treatment on growth, yield and nutrient uptake by blackgram in Alfisols

Migrated silicon dioxide nanoparticles activates the rice immunity for systemic resistance against two pathogens

Rice, the world's primary staple food, is under severe threat from several devastating diseases. To sustainably management rice diseases, developing safe, environmentally friendly alternatives urgently need to be developed. In this study, we synthesized two silicon dioxide nanoparticles, spherical mesoporous silica nanoparticles (MSNs) and virus-like mesoporous silica nanoparticles (VMSNs), and we performed a resistance assay on rice for two major diseases, bacterial blight caused by Xanthomonas oryzae pv. oryzae and sheath blight caused by Rhizoctonia solani. Compared to the control, the two nanoparticle treatments increased rice resistance, with VMSNs exhibiting the highest efficacy in controlling these two diseases, causing a shorter lesion length than those plants treated by MSNs. Coincidentally, the foliar application of VMSNs activates a higher expression level of several pathogenesis-related (PR) genes compared to those of MSNs and SiO2 treatment. By using fluorescein isothiocyanate (FITC)-labeled VMSNs (VMSNs-FITC) to soak the top expanded leaf tips or roots, we observed that the fluorescence of the nanoparticles firstly accumulated at the local site of the top leaves or roots, rapidly migrated to the hypocotyl of rice, and then redistributed sequentially from the bottom leaves to the upper leaves. Furthermore, the foliar or root application of VMSNs-FITC could trigger the local and systemic resistance to PXO99. Notably, no significant toxicity was observed on plants and mice after excessive foliar treatment or feeding tests, respectively. Overall, our research revealed that VMSNs are an effective, systemic, and safe nano-pesticides for controlling rice diseases. Boosting the immune responses may be associated with the transporting of nanoparticles.

Boosting Stevia's sweetness: Growth regulators mitigate salt stress and enhance steviol glycosides

Stevia rebaudiana Bertoni is a plant species with sweet-tasting leaves that can be used as a natural, low-calorie sweetener with potential health benefits. Salt stress can reduce plant growth and productivity, but the application of growth regulators like salicylic acid (SA), methyl jasmonate (MeJ), and spermidine (Spd) can manage various plant abiotic stresses and improve plant growth and productivity. In this work, we investigated the role of exogenous SA, MeJ, and Spd in conferring salt stress tolerance in Stevia by analyzing plant growth, chlorophyll (Chl), total phenolic, total carotenoid content, antioxidant defense system and steviol glycosides. The aim of a recent study was to assess the effects of these regulators on Stevia plants under both individual and combined salt stress conditions. Foliar application of these regulators improved plant growth under salt stress, with moderate salinity stress increasing glycoside compounds. SA was most effective in increasing rebaudioside A (Reb A), while MeJ + Spd combination was best for increasing stevioside (Stv) content. Individual applications of Spd, MeJ, and SA significantly impacted plant growth and antioxidant content, although their combined use was less effective. Spd application under salt stress yielded the highest increases in total carotenoid and Chl a content, while MeJ and Spd together significantly boosted Chl b content. The study found that SA enhanced superoxide dismutase (SOD) activity and reduced catalase (CAT) activity under salt stress, whereas MeJ alone increased both CAT and SOD activity. The distinct responses to Spd, SA, and MeJ suggest varied mechanisms in oxidative stress-induced antioxidant production. Overall, the use of these growth regulators can improve the growth, yield, and nutritional value of Stevia under salt stress, offering significant implications for agriculture and food security.

Alleviating salinity stress in Cyamopsis tetragonoloba L. seedlings through foliar application of silicon or melatonin in arid and semi-desert environments

Salinity stress can be deemed as an important challenge extremely affecting crop growth as well as development. Therefore, it is important to improve its tolerance to salinity stress, in arid as well as semiarid regions. Thus, this experiment explored the influence of foliar usage of plant growth-stimulating substances with different concentrations (C: control, melatonin (M1: 100, M2: 200 and M3:400 µM) and silicon (Si1: 5.4, Si2: 10.8 and Si3: 16.2 mM)) on some physiological as well as biochemical attributes of Cyamopsis tetragonoloba L. (guar) seedlings under five salinity levels (S1: no-salt treatment, S2: 5, S3: 10, S4: 15 and S5: 20 dS m−1). With increasing salinity, shoot dry weight, Fv/Fm, F′v/F′m, ΦPSII, qp, qL, Rfd, ETR, photosynthetic pigments, membrane stability index, as well as relative water content were gradually reduced in salt-stressed guar, as comparison is made to the non-saline conditions. However, foliar usage of plant growth-stimulating substances was effective in improving guar tolerance to salinity by elevating the DPPH radical scavenging capacity and anthocyanin, thus enhancing membrane stability index, improving the electron's transport rate, reducing electrolyte leakage and decreasing the damage affecting the reaction center of PSII, as comparison is made with control. Such positive effects were exhibited in elevating growth under salinity stress. Si3 treatment demonstrated the best response under salinity stress, as compared with the other treatments. Consequently, foliar usage of silicon or melatonin in salt-stressed guar seedlings can serve an efficient method to improve salt tolerance under salinity stress in arid and semiarid regions.

Effect of foliar application of major plant nutrients on yield and economics of rabi sorghum (Sorghum bicolor L.)

Effect of foliar application of major plant nutrients on yield and economics of rabi sorghum (Sorghum bicolor L.)

Effect of foliar application of nitrogenous fertilizers on growth attributes, soil properties, quality and productivity of wheat (Triticum aestivum L.)

Effect of foliar application of nitrogenous fertilizers on growth attributes, soil properties, quality and productivity of wheat (Triticum aestivum L.)

Effect of sulfur and potassium foliar applications on wheat grain protein quality

ContextThe effects of sulfur and potassium fertilizers on wheat yield and quality have been well studied, but most of them are used as basal fertilizers. However, the root system is senescent at the later stages of wheat growth and cannot absorb sufficient sulfur and potassium fertilizers plant needed. It is still unclear whether sulfur and potassium foliar applications at the later stages can affect wheat yield and quality. ObjectiveThis experiment was conducted to investigate the changes of sulfur and potassium accumulation and transport, protein synthesis and flour processing quality after foliar application of sulfur and potassium fertilizers, transport and the relating physiological mechanisms. MethodsIn 2020–2021 and 2021–2022, a three-factor split plot experiment was carried out in the middle and lower reaches of Yangtze River, with wheat variety, concentration of sulfur fertilizer and potassium fertilizer served as main factor, subfactor and sub-subfactor respectively. ResultsIn the study from 2020 to 2022, the albumin protein content of both varieties decreased in the nutrient spraying treatment, particularly in the high potassium level. However, there was no significant effect on the globulin content. Moreover, the gliadin protein content decreased in the sulfur spraying treatment alone, but significantly increased the wheat gluten content, and thereby the total protein content. We also found significant genotypic differences in the composition and content of high molecular weight wheat glutenin subunits (HMW-GS) between the two varieties. The foliar spraying of sulfur and potassium fertilizers significantly increased the content of subunits 1 and 8 in Yangmai (YM15) and subunits 7 and 12 in Yangmai (YM16), and the effect of mixed spraying was better than single-nutrient spraying, especially the amount of 0.2 % sulfur and 0.3 % potassium fertilizer treatment. ConclusionsThe superimposed effect of sulfur and potassium effectively increased the total protein content by promoting the accumulation of sulfur in transit to the seeds, increasing the substrate supply level, and enhancing enzyme activity. Although sulfur and potassium combination can improve the grain protein quality and flour processing quality, too high spraying concentrations can decrease the flour processing quality. ImplicationsSpraying the appropriate amount of 0.2 % sulfur and 0.3 % potassium fertilizer can serve as an optimization measure for high-quality and efficient production of different types of wheat varieties.

Evaluation of three doses of urea applied to leaves, sprayed at pre-veraison and veraison, on Tempranillo must volatile composition over two seasons

The volatile composition of grapes has a direct impact on the final aromatic composition of wine and plays a crucial role in determining its quality. Various factors, such as agronomic practices, climatic conditions or grape variety, can influence the volatile composition of grape juices. This study aimed to determine the influence of three doses of urea, applied at two different phenological stages (pre-veraison and veraison), on the volatile composition of Tempranillo musts, during two consecutive seasons. The urea application did not have an impact on the yield of the vineyard or the general parameters of the Tempranillo must. However, the three different concentrations of urea modified the volatile composition. Specifically, the higher concentration of urea improved the terpenoids, C13 norisoprenoids, and benzenoid compounds in grape juice. Additionally, when urea treatments were applied at pre-veraison, terpenoids, C13 norisoprenoids, esters, and benzenoid compounds were improved in Tempranillo must. However, the weather was an important factor influencing the volatile compounds in Tempranillo musts. Consequently, foliar applications of urea could be an interesting viticulture practice in order to enhance the volatile compounds in Tempranillo musts.

Cobalt associated with potassium phosphite improves the post-harvest quality of mango cv. Palmer

Mango is a highly perishable climacteric fruit with a short post-harvest period. Therefore, to extend shelf life, the mangoes were treated pre-harvest with a potassium phosphite solution (1.4 g/mL KH2PO4) and a control solution (0 g/mL KH₂PO) associated with different doses of cobalt (0; 48; 64; 80; 112 ml.plant-1) at a density of 1.30 g/mL. The work measured physical, chemical, and biochemical variables. Cobalt and potassium phosphite favored maintaining color and firmness and reduced the respiratory rate. The treatments significantly affected the chemical variables, reduced the soluble solids content, conserved ascorbic acid, and preserved the pH. Foliar application of cobalt and potassium phosphite at pre-harvest is an efficient technique for improving shelf life and maintaining mango quality during storage at room temperature.

Effect of Calcium Formulations to Increase Yield and Shelf Life of Manjri Naveen Grapes

The application of Calcium at veraison stage maintain the quality of grapes. Hence to evaluate the effect of Calcium formulations for increasing yield and the shelf life of Manjri Naveen grapes. The experiment was designed as randomized block design (RBD) having seven treatments and four replications (1 replicate = 4 vines). Three calcium formulations were used i.e. CaCl2, CaO, Ca(No3)2 as a dose of (2.5 g/l) and (5 g/l). Foliar application of calcium was done 10 days before harvest at veraison stage. Results obtained from the experiment showed the lowest weight loss was found in bunches of calcium oxide and calcium chloride spray treatments (8.14 %), (8.61 %) respectively, while the highest weight loss (10.36 %) occurred in untreated control. The PLW increased significantly at successive from 1.32 % on 1st day to 10.36 % on 7th day of storage at room temperature. CaO at 5 g/l recorded the lowest fallen berries 2.70 (%), followed by Ca(NO3)2 at 2.5 g/l recorded 3.38 (%). It might be due to calcium accumulated mostly in the rachis and less in the flesh during grape berry development. Yield and quality components like bunch weight, berry weight, total yield/vine, TSS, TSS/Acidity ratio were significantly influenced by calcium spray. Hence from this study it is concluded that the foliar application of CaO at 5 g/l was found to be effective for increasing the shelf life and yield of Manjri Naveen grapes.

Comparative Evaluation of Calcium Sources and their Mode of Use on Apple Production in Acidic Soil under High Density Plantation System

Apples grown in Kashmir province are extremely prone to deterioration, particularly in post-harvest storage. Calcium is amongst the vital mineral element deceiving apple fruit quality, predominantly in acid soils deficit in available calcium. Calcium in sufficient quantity helps to retain apple fruit firmness and reduces the occurrence of physiological disorders, it also plays essential role to improve yield and quality of produce. Modes of calcium application and its different doses on two apple varieties was tested to improve yield and quality at Ambri Apple Research Centre, Sher-e-Kashmir University of Agricultural Sciences and Technology, Kashmir, India. The direct application of calcium to apple as spray is most effective method for escalating fruit calcium content and quality. Among sources and their mode of application calcium nitrate foliar application performed better than foliar application of calcium chloride in improving fruit quality and yield of Golden Delicious than Red Chief Camspur, whereas soil application of calcium nitrate showed least response to improve fruit quality and yield in both varieties under acidic soil atmosphere. Physiological loss in weight at 30 days and 60 days after harvesting was lower in foliar applied calcium than soil calcium application. The significant variation in total sugar content and TSS of apple fruits were observed in different calcium sources and their mode of application. Calcium nitrate foliar spray performed better than calcium chloride foliar spray in improving fruit quality. Our study did not find any adversity of dosage in plants whether applied to soil or directly to plant and we did observe better yields and quality at higher calcium doses. Among varieties Golden Delicious performed better than Red Chief Camspur. Results of research evidenced that preharvest calcium sprays increase yield, improved fruit quality and reduced its deterioration in post-harvest storage.

Effect of Foliar Spray of Micro - Nutrients on Fruit Growth and Yield of Guava (Psidium guajava L.) cv. Lalit

Aim: To examine the effect of foliar spray of micro - nutrients on fruit growth and yield of guava (Psidium guajava L.) cv. Lalit. Study Design: The Randomized Block Design (RBD) experimental design was used. Place and Duration of Study: An experiment was carried out during Hasth Bahar flowering seasons of 2021-22 and 2022-23 at Horticulture Research Farm of Babasaheb Bhimrao Ambedkar University. Methodology: There were nineteen treatments with three replication. The variety selected for experiment was Lalit. Results: The foliar application of Borax 0.2%+Zinc 0.4% was found to be the best treatment in improving the morphological characteristics of guava such as fruit length (8.59 cm), fruit width (8.6cm), fruit volume (169.09 cm), fruit weight (174.99 g), peel weight (17.13g), pulp weight (155.32g),number of seed per fruit (212.49),seed weight per fruit (2.53g), seed weight kg per plant (1.23 kg), pulp and seed ratio (61.29) and specific gravity (1.03 g cc-1) of guava fruit. Conclusion: On the basis of the result obtained in the present investigation, it is concluded the combined foliar application of Borax 0.2%+Zinc 0.4% (T11). Therefore, combined spray Borax 0.2%+Zinc 0.4% (T11) can be advocated to guava growers for maximum growth and yield parameters of guava.

Investigating the positive effects of salicylic acid on peppermint (Mentha piperita l.) under different soil salinity conditions: comprehensive morphological, mineral, and biochemical analyses

This study explored the effects of salicylic acid on the growth and biochemical responses of peppermint (Mentha piperita L.) under different soil salinity levels, a major challenge in agricultural productivity. The experiment was conducted using a factorial design with salicylic acid applied at concentrations of 0, 5, 10, and 50 ppm, combined with sodium chloride-induced salinity at 0, 1,000, 2,000, and 3,000 mg kg–1 soil. Results demonstrated that increasing soil salinity negatively impacted plant growth, reducing plant height, leaf number, and the dry weight of aerial parts. Salinity stress also led to reduced nutrient uptake, particularly for essential elements like calcium and potassium, while increasing sodium levels in plant tissues. However, the foliar application of salicylic acid, especially at 50 ppm, significantly improved growth parameters and mitigated the detrimental effects of salinity. Notably, at the highest salinity level (3,000 mg kg–1), salicylic acid enhanced plant height by 11.1% and leaf number by 30.9% compared to untreated plants. Salicylic acid also boosted biochemical responses, such as increasing total phenolic and flavonoid content, which are critical for stress tolerance. This study underscores the potential of salicylic acid as a stress mitigator, promoting better growth and physiological resilience in peppermint under saline conditions, offering valuable insights for improving crop performance in salinity-affected regions.

Precision drip Irrigation System and Foliar Application of Biostimulant and Fertilizers Containing Micronutrients Optimize Photochemical Efficiency and Grain Yield of Maize (Zea mays L)

Abstract Asymmetric drought propagation and depletion of soil nutrients threaten cereal crop productivity worldwide, calling for the application of validated agronomic practices to curtail their effect on crop production. This study evaluated the effect of precision drip irrigation, biostimulant, and micronutrients application on photochemical efficiency and yield of maize.An experiment laid in a randomized complete block design with irrigation and water stress was established in 2022 and 2023 growing seasons at the experimental area of the University of Debrecen. Other treatments included T1 (non-microbial biostimulant from plant origin), T2 (zinc based chemical fertilizer), T3 (boron and molybdenum based chemical fertilizer), and T4 (control). Data was collected on steady-state fluorescence (F’), maximal fluorescence (Fm’), quantum photosynthetic yield or efficiency of photosystem II (ΦPSII or Y(II)), electron transport rate (ETR), and grain yield and yield components. Precision drip irrigation significantly optimized ΦPSII, ETR, cob weight, number of seeds per cob, weight of 1000 seeds and grain yield. The biostimulant and micronutrients optimized Fm’, ΦPSII, and ETR at VT and R2 growth stages. Regardless of the water management regime, T1, T2 and T3 seasonally optimized grain yield. Between water management regimes, biostimulant had the highest yield optimization effect under precision drip irrigation in the season with elevated water stress.Optimum photochemical efficiency and grain yield is achievable through precision drip irrigation, biostimulant, and micronutrient application. However, further research involving 2–3 application times at critical stages of maize under precision drip irrigation and/or combined application of these treatments at season specific precision drip irrigation is required.

Bacterial endophyte Pseudomonas mosselii PR5 improves growth, nutrient accumulation, and yield of rice (Oryza sativa L.) through various application methods

BackgroundPseudomonas spp. have drawn considerable attention due to their rhizospheric abundance and exceptional plant growth-promoting attributes. However, more research is needed on the optimal application methods of Pseudomonas mosselii for rice growth, nutrient accumulation, and yield improvement. This research explored the application of the endophytic bacterium P. mosselii PR5 on rice cultivar BRRI dhan29 with four treatments: control, seedling priming, root drenching, and bacterial cell-free culture (CFC) foliar application.ResultsPR5 led to better rice growth, improved nutrient acquisition, and higher yields compared to the control, regardless of the application method used. The highest results in fresh weight of root (146.93 g/pot), shoot (758.98 g/pot), and flag leaf (7.88 g/pot), dry weight of root (42.16 g/pot), shoot (97.32 g/pot), and flag leaf (2.69 g/pot), and grains/panicle (224.67), were obtained from seedling priming treatment, whereas root drenching resulted in maximum plant height (105.67 cm), root length (49.0 cm), tillers/pot (23.7), and panicles/pot (17.67). In all three application methods, rice grain yield per pot was higher in PR5 inoculated treatments, compared to the control. The amount of P, Mg and Zn in the shoot and N, P, Ca, Mg and Si content in the flag leaf was significantly increased along with effective suppression of naturally occurring blast disease in bacterial CFC foliar application, validated by multivariate analysis.ConclusionOur results indicated that rice seedlings priming with PR5 improved rice growth, yield and nutrient uptake, whereas CFC foliar application significantly increased the concentration of most nutrients in the rice plant and suppressed the naturally occurring rice blast disease. This research highlights the significant potential of P. mosselii PR5 in enhancing rice growth, yield, and nutrient uptake, particularly through seedling priming and CFC foliar application methods.

Impact of iron sulfate (FeSO4) foliar application on growth, metabolites and antioxidative defense of Luffa cylindrica (Sponge gourd) under salt stress

Salt stress is becoming a major issue for the world’s environment and agriculture economy. Different iron [Fe] sources can give an environmentally friendly alternative for salt-affected soil remediation. In this study the effects of Iron sulfate on Luffa cylindrica (Sponge gourd) cultivated in normal and saline water irrigated soil were examined. When FeSO4 (0.01, 0.025, 0.05, 0.1 ppm) were applied to salt affected soil, the length, fresh and dry biomass of sponge gourd plant roots and shoots inclined by an average of 33, 28, 11, 21, 18 and 22%, respectively. In plants irrigated with saline water, leaf count was raised successively (23–115%) with increasing concentration of FeSO4 (0.025-0.1 ppm) compared to stress only plants. The use of FeSO4 boosted sponge gourd growth characteristics in both normal and salt-affected soils compared to respective controls. The application of Iron sulfate under salt stress boosted photosynthetic indices such as chlorophyll a (22%), chlorophyll b (34%), carotenoids (16%), and total chlorophyll levels (22%). Iron sulfate application also exhibited incline in primary (total free amino acids, 50%; total soluble proteins, 46%) and secondary (total phenolics, 9%; flavonoid content, 51%) metabolites in salt-affected soils. Oxidative enzymatic activities such as catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) and DPPH scavenging activity (36%) were also increased by foliar spray of FeSO4 in control and salt stressed L. cylindrica plants. FeSO4 had a considerable impact on the growth and development of Luffa cylindrica in normal and salt-affected soils. It is concluded that FeSO4 application can effectively remediate salt affected soil and improve the production of crop plants.

Brassinosteroids Alleviate Salt Stress by Enhancing Sugar and Glycine Betaine in Pepper (Capsicum annuum L.).

Salt stress is a major abiotic factor that negatively impacts the growth, performance, and secondary metabolite production in pepper (Capsicum annuum L.) plants. Brassinosteroids (BRs) play a crucial role in enhancing plant tolerance to abiotic stress, yet their potential in mitigating salt stress in pepper plants, particularly by promoting sugar and glycine betaine accumulation, remains underexplored. In this study, we investigated the effects of the foliar application of 2,4-epibrassinolide (EBR) on salt-stressed pepper seedlings. Our findings revealed that EBR treatment significantly increased the levels of proline, sugar, and glycine betaine under salt stress compared to untreated controls. Moreover, EBR enhanced the antioxidant defense mechanisms in pepper seedlings by increasing sugar and glycine betaine levels, which contributed to the reduction of reactive oxygen species (ROS) and malondialdehyde (MDA) accumulation.

Optimizing Olive Production: The Role of Foliar Fertilizers in Boosting Yield and Quality

To enhance yield and produce high-quality olive products, it is crucial to implement accurate and balanced fertilization programs. Like other crops, olive trees require the application of specific macro and micronutrients in addition to basic fertilization. This study aimed to evaluate the effects of foliar fertilizer applications containing K as well as N, K, Ca, and B, in addition to basic fertilization, on the yield and quality parameters of the Gemlik olive (Olea europaea L. cv. Gemlik) variety, known for its high economic value and use in black table olives and oil production, during two consecutive seasons in 2021–2022. The research evaluated the effects on olive fruit yield, fruit nutrient content (N, Ca, P, Na, K, Mg, Zn, Fe, Cu, and Mn), oil yield, and quality. In addition to traditional basic fertilization (NPK fertilizer), foliar fertilizers containing K as well as N, K, Ca, and B nutrients were applied before flowering and after fruit set. These applications were organized using a randomized block design with three replicates, each consisting of three trees. The results showed that foliar fertilizer applications, in addition to basic fertilization, had a significant impact on the yield and quality parameters. Specifically, foliar K applications positively affected olive yield in the second year. Moreover, foliar fertilizer applications improved the fruit nutrient content, oil quality (K-232, K-270, peroxide, acidity, and total phenol), and oil composition (%). Therefore, it is recommended that foliar fertilizers are applied during similar periods under similar conditions. However, ensuring the continuity of an optimal fertilization management plan is crucial for olive, as it is a perennial plant.