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Monitoring the nutrient status of citrus orchards is fundamental to ensure optimum fruit yield and quality. In the present study, soil and leaf samples of 20 Valencia Late orange orchards were collected in the Gharb plain of Morocco, the second-largest citrus area in the country. The objective was to assess the status of essential macronutrients (N, P, K, Ca, and Mg) and micronutrients (Fe, Zn, Cu, and Mn) in Valencia orange orchards and investigate the relationships between soil properties and nutrient contents in soils and leaves. Soils of the studied orchards had a medium to heavy texture, with low to moderate levels of organic matter content (6–31 g kg−1). They were also non-saline and mostly alkaline and calcareous. These soils exhibited a wide range of macro- and micronutrients. Suboptimum levels of total N, available Fe, and Cu were observed in most soils. Most of soils had also sufficient levels of available P, Mn, and Zn. All soils were sufficiently supplied with available Ca, Mg, and K. Similarly to soil analysis, leaf analysis indicated the prevalence of adequate to very high levels of P, Ca, Mn, and K. Leaf N and Fe status were below optimum levels in most orchards, which is in line with the observed low levels in soils. Nevertheless, unlike soils, leaves did not show any deficiency of Cu; instead, most orchards had adequate to excessive levels of this micronutrient. Additionally, leaf Mg and Zn status were deficient in most orchards, conversely to that of soils. This discrepancy between soil and leaf analysis was also noted in the lack of correlation we observed between soil nutrients and their respective levels in leaves. Correlation analysis revealed also an antagonistic interaction between K–Mg and Ca–Mg, which explained the widespread suboptimum levels of Mg in leaves despite its sufficient status in soils. Such antagonism was also observed between Fe–Mn. In the case of Cu, we suspect the use of Cu-containing plant protection products to contribute to the high levels in leaves despite its low levels in soils. Overall, our results showed that nutrient imbalances leading to antagonistic interaction heavily impacted nutrient status in our study area. We expect unbalanced fertilization to contribute to this issue. Therefore, fertilization practices should be managed judiciously to maintain an adequate nutrient balance in the soil and trees of citrus orchards and ensure their sustainable production. [ABSTRACT FROM AUTHOR]

Vale do Ribeira is one of the largest banana producing regions in Brazil. However, information on soil fertility and nutrient status that could limit fruit production remains scarce. Thus, the present study diagnosed the most limiting nutrient parameters for the Nanica and Prata banana cultivars, in Vale do Ribeira, São Paulo State, based on soil and leaf chemical analyses. The data assessed included samples from commercial plantations in the municipalities of Eldorado, Cajati, Jacupiranga, Pariquera-açú, Registro and Sete Barras, between 2012 and 2020. The results of soil (pH, V, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) and leaf chemical analyses (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) were interpreted according to literature values and their maximums, minimums, means, coefficients of variation (CV), and confidence intervals (CI) were calculated at P < 0.05. Parameter classes were assessed according to their frequency distribution. A large part of the samples exhibited pH and V values similar to those recommended for banana plants. Although, average soil nutrient concentrations were considered high, soil K, Mg and S levels did not provide adequate banana plant nutrition, since these nutrients were deficient in the plants. [ABSTRACT FROM AUTHOR]

The district Toba Tek Singh is located in the center of Punjab province. It occupies 2nd important position in national citrus production after Sargodha, with citrus orchard area of 11412 hectares and annual production of 160758 tons. Citrus productivity in Pakistan, in general, and Toba Tek Singh, in particular, is far below its its potential which could be attributed to several factors but poor soil health and inadequate soil fertility may be considered an important reason. A comprehensive nutrient indexing survey of thirty citrus orchards grown in different parts of district Toba Tek Singh was conducted to evaluate the soil characteristics and plant nutrient status. GPS coordinates of selected sites were recorded prior to sampling. Soil samples were coll ected at 0-20 cm, 21-40 cm and 41-60 cm depth using standard procedure. Five soil samples were collected from each site to get a composite sample for each depth. The leaf samples were collected from the 7-month-old non-fruiting branches of plants around the tree canopy during the month of September, 2022. Five healthy and uniform citrus trees were sampled from each site to get a composite leaf sample. The soil samples were analyzed for pH, electrical conductivity (EC), soil organic matter (SOM) and calcium carbonate (CaCO3). The soil and leaf samples were analyzed for macro and micronutrients. It was found that most of orchard soils of district Toba Tek Singh were moderately alkaline (pH 7.52-8.90), slight to strong calcareous (2-15% CaCO3), non-saline (0.77-3.0 dS m-1 EC) and low in SOM (0.23-1.49%) with low to medium nitrogen (0.01-0.06%) and phosphorus (0.58-10.52 mg kg-1) while medium to high potassium (56.47-315.34 mg kg-1). The sampled soils were low to marginal in boron (0.09-0.72 mg kg-1), copper (0.05-0.59 mg kg-1), iron (0.23-10.75 mg kg-1) and zinc (0.03-1.83 mg kg-1) while adequate in manganese (1.35-26.20 mg kg-1). Leaf analysis revealed that almost 50% orchards were deficient in phosphorus (0.05-0.23%) and potassium (0.40-1.76%), while having low to marginal values of copper (1.96-20.99 mg kg-1), zinc (4.13-31.96 mg kg-1), boron (3.12-95.40 mg kg-1), manganese (42.62- 96.46 mg kg-1) but adequate iron (171-552 mg kg-1). The surveyed orchard soils were mostly alkaline calcareous, deficient in organic matter and having low to moderate macro and micronutrients. [ABSTRACT FROM AUTHOR]

Inconsistent results on the effects of humic substances (HS) on yield and nutrient status of important food crops, including oilseeds, confirm the need for further research on different HS products to match their use to actual field conditions. The aim of this study was to evaluate the effect of foliar application of commercially produced peat- and vermicompost-derived HS preparations on nutrient status and yield of spring oilseed rape (Brassica napus). The field experiment was carried out in Stende State Cereals Breeding Institute, Latvia, during the vegetation season of 2012, using the spring oilseed rape cultivar 'Perfect'. Although foliar sprays of HS were applied during the critical stages of crop development from rapid growth to flowering, they were ineffective in improving the supply of the deficient nutrients (N, K, B, Zn, Cu) in leaves. Moreover, both tested HS products caused a decrease in Cu and B content in the seeds, which resulted in a negative trend in oilseed rape seed yield. Therefore, the conducted experiment demonstrated that foliar application of both HS preparations was ineffective to promote nutrient status and did not contribute to spring oilseed rape yield. [ABSTRACT FROM AUTHOR]

Computer vision is a powerful technology that has enabled solutions in various fields by analyzing visual attributes of images. One field that has taken advantage of computer vision is agricultural automation, which promotes high-quality crop production. The nutritional status of a crop is a crucial factor for determining its productivity. This status is mediated by approximately 14 chemical elements acquired by the plant, and their determination plays a pivotal role in farm management. To address the timely identification of nutritional disorders, this study focuses on the classification of three levels of phosphorus deficiencies through individual leaf analysis. The methodological steps include: (1) using different capture devices to generate a database of images composed of laboratory-grown maize plants that were induced to either total phosphorus deficiency, medium deficiency, or total nutrition; (2) processing the images with state-of-the-art transfer learning architectures (i.e., VGG16, ResNet50, GoogLeNet, DenseNet201, and MobileNetV2); and (3) evaluating the classification performance of the models using the created database. The results show that the DenseNet201 model achieves superior performance, with 96 % classification accuracy. However, the other studied architectures also demonstrate competitive performance and are considered state-of-the-art automatic leaf nutrition deficiency detection tools. The proposed method can be a starting point to fine-tune machine-vision-based solutions tailored for real-time monitoring of crop nutritional status. [ABSTRACT FROM AUTHOR]

Fertilizations is one the efforts done to increase the production and quality of crops. Nitrogen, phosphorus and potassium fertilizers rate used in the production of Onion are excessive, so the essential elements present in the soil can be imbalanced ,nutrient balance determines crop yield and quality. This research aimed to evaluate Onion productivity subjected to various ratios of(NPK) to establish the DRIS-Norms and indexes, by using leaf nutrient analysis. The Diagnosis and Recommendation Integrated System-DRIS depended on interrelation between elements, compares crop mineral nutrient proportions with DRIS-norms (Optimal values) and we can know imbalances, deficiencies and excesses in nutrient of plants .The research was conducted in the experimental farm of college of agriculture ,university of Salahaddin in Grdarash field Erbil-Iraq,3.5Km to the south of Erbil city, (36° ON, 44° 01 E), (0411359, 03997002 UTM) ,planting date 30/1/2020 and harvesting at 30/6/2020 so the research period 5 months. We used spilt – spilt design in the experiment, first factor was Nitrogen (0, 40, 80, 160 Kg.ha-1), second factor was Phosphorus (0, 80, 160 Kg.ha-1) and the third factor was Potassium (0, 50, 100 Kg .ha-1) .The results indicated that the best fertilizer combinations that recorded highest Onion-Yield (18.36 Mg. ha-1) was(K 50 Kg. ha-1, P 160 Kg. ha-1, N 40 Kg. ha-1) which had lowest Nutrient Balance Index-(NBI), its values was (9.04) but the highest value was (73.18) for (K0P0N0) treatment.

The Compositional Nutrients Diagnosis (CND) can establish indexes that establish deficiency, normality or excess, and even critical levels (CL) or sufficiency ranges (SR) in grapevine leaves. However, this information is scarce in 'White Moscato' and 'Bordeaux' cultivars cultivated in subtropical regions of the world. The study aimed to propose the CND, CL and SR indexes of nutrients in leaves of 'Bordeaux' and 'White Moscato' grapevine cultivars, cultivated in subtropical conditions. Leaves were collected from 105 'White Moscato' and 'Bordeaux' vineyards. Leaves were prepared, dried, ground and subjected to chemical nutrient analysis. Productivity was evaluated. The nutritional status of the grapevine was calculated using the CND method. The CND-r² indexes were effective in establishing the nutritional status of 'White Moscato' and 'Bordeaux' grapevines, in relation to the concentration of nutrients in leaves of N, P, K, Ca, Mg, B, Cu, Fe, Mn and Zn in deficient, adequate and excessive concentrations. The application of the CND method in the grapevine database showed lower SRs for macronutrients N, K, Ca, Mg and S, and the breadth of the nutritional range for nutrients N, K, Mg, and Fe was smaller than reported in literature. The CND methodology established the critical level and nutrient sufficiency ranges suitable under current grapevine production conditions. Multi-nutrient combinations were more effective than the analysis of a single nutrient in expressing that the limitation of a certain element can reduce the productivity of the grapevines. [ABSTRACT FROM AUTHOR]

Leaf analysis is an important tool to assess the nutritional status of coffee crops and allow evaluate and calibrate fertilizers recommendations. For the interpretation of the chemical results obtained by leaf analysis, several methods can be used, stands as the Sufficiency Range and the Integrated System of Diagnosis and Recommendation (DRIS). The objective of this work was to evaluate the nutritional status of coffee crops in production from Manhuaçu region, Minas Gerais State, Brazil. A database was generated with nutrient concentrations from index leaves of commercial fields located in the region of Manhuaçu. Some parameters of descriptive statistics were used to describe the leaves concentrations (mean, maximum value, minimum value, and coefficient of variation). The nutritional status of the plants was evaluated by the Sufficiency range and DRIS methods. Nutritional imbalances may be one of the factors responsible for low yields over years. The program of fertilizations must be reviewed in the Manhuaçu region, once N and K are in excess and P and S deficient in coffee fields. [ABSTRACT FROM AUTHOR]

Genus Eucalyptus can be grown in different soils worldwide, although it is not always ready to fulfill plants' nutrient demands. Whenever such nutrient shortage happens, it is necessary applying the nutrients missing, which can be established based on the critical levels and sufficiency ranges (SRs) of nutrients in leaves or by multivariate mathematical models, such as the composition nutrient diagnosis (CND). This study aimed to investigate the nutritional status of Eucalyptus plantations in Brazil, based on the CND method. A total of 119 12-month-old Eucalyptus saligna (E. saligna) plantations were sampled in the Rio Grande do Sul State (RS), Southern Brazil. Nutrient concentration in leaves and the diameter at breast height (DBH) was measured. The E. saligna nutritional status was calculated through the CND method. High- and low-yield populations were set based on DBH of 4.2 cm. The SRs proposed by the CND method were narrower than the ones proposed by official recommendations for Eucalyptus, especially for magnesium (Mg), boron (B), and iron (Fe). The CND-r2 index recorded for each nutrient generated a limitation order for nutrients. The greater accuracy of the recommendations proposed by the CND method, compared with univariate and bivariate methods, contribute to reducing the use of fertilizers. [ABSTRACT FROM AUTHOR]

Copyright of Mustafa Kemal University Journal of Agricultural Sciences / Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi is the property of Mustafa Kemal University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Kirkuk University for Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study was carried out to evaluate the leaf nutrient status of commercially grown strawberries in Latvia during 2014–2022. The results of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo and B in 200 strawberry leaf samples from different strawberry-producing farms were analysed over three periods: 2014–2016, 2017–2019, and 2020–2022. According to leaf analyses, plant fertilization was only partly well managed by the growers. During the research period, strawberries in Latvia were generally sufficiently supplied with N, P, K, Mg, Fe, Mn, Mo, and B, while the level of Ca, S, Zn, and Cu was considered low. The deficiency of these nutrients was characteristic for more than 50% of the samples. Since Ca, S, Zn, and Cu are essential for berry formation and quality and contribute to stress resistance; their deficiency could be one of the limiting factors for strawberry yield. The significant positive correlations found between nutrients, including deficient ones, confirmed their close relationship in the uptake process and the importance of sufficient supply. The results clearly indicated that fertilization could currently be an issue that limits the strawberry harvest in Latvia, and adequate provisions of Ca, S, Zn, and B should be the main focus. [ABSTRACT FROM AUTHOR]

Leaf analysis is essential for diagnosing nutritional status and guiding fertilizer application. The present study aimed to investigate the appropriate time for leaf sampling and the effect of genotype on olive nutrition. We determined leaf nutrient concentrations of calcium (Ca), iron (Fe), and manganese (Mn) in five Greek (‘Amfissis’, ‘Chondrolia Chalkidikis’, ‘Koroneiki’, ‘Mastoidis’, and ‘Kalamon’) and one Spanish (‘Picual’) variety from May 2019 to April 2020. The concentrations of Ca, Fe, and Mn were significantly affected by genotype and season. The highest concentrations for all nutrients were determined in April, while the lowest were in May, June, and October. Leaf Ca concentration significantly increased progressively from May to September for all the varieties. Leaves of ‘Koroneiki’ had the highest Ca concentration. Iron concentrations were within the sufficiency thresholds for all the varieties during the whole experimental period, and ‘Mastoidis’ showed the highest concentration. Leaf Mn concentration for all the varieties increased from May to September with an instant decrease in June, apart from ‘Amfissis’. The varieties ‘Kalamon’ and ‘Chondrolia Chalkidikis’ were found to be above the Mn sufficiency threshold throughout the year. Variations among season and genotype depict the complexity of nutrient transportation in leaf tissues.

Analysis of composite pecan leaf samples typically used to determine need for nutrient applications does not account for variability among trees in the sampled area. To account for this unmeasured variability, pecan orchard block nutrient standards are greater than actual single tree nutrient requirements. In 2018 and 2019, we measured variability in a pecan orchard block by evaluating nutrient status of all trees in a study area consisting of two cultivars (Wichita and Western) grafted on open-pollinated ‘Ideal’ seedlings. Foliar zinc (Zn) coefficient of variation (cv) ranged from 0.186 to 0.255 within individual cultivars and years but was as high as 0.30 when combining cultivars within a year. The ‘Western’ cultivar had higher foliar Zn concentrations than ‘Wichita’, but Zn concentrations were not consistently associated with other leaf nutrient levels, soil Zn status, or other soil properties. Using observed foliar Zn variability, we determined that it is necessary to sample 35 trees for a composite sample to achieve a relative margin of error of 10% and 95% confidence level in a pecan orchard block with more than 1000 trees. We developed field scale foliar Zn recommendations based on individual tree research that indicates a minimum acceptable leaf Zn concentration of ≈15 mg·kg–1 is needed to maintain optimal photosynthetic function in Zn chelate fertigated pecan trees. Assuming a Zn cv of 0.30 and a composite sample comprised of leaves from 35 trees, the minimum acceptable orchard block Zn level to ensure that less than 5% of trees had suboptimal levels of Zn was 27.6 mg·kg–1. An orchard block Zn level below 23.4 mg·kg–1 indicates that more than 5% of trees in the block had suboptimal foliar Zn concentrations.

The foliar analysis is a useful tool to detect the nutritional status of plants, predict future problems in the reproductive cycles of fruit production and implement preventive and corrective measures to achieve a mineral balance in fruit trees, obtaining higher productivity. There is little information available on nutrient sufficiency ranges in pomegranate leaf and the literature reported differs due to diverse cultivation practices, cultivars, and agroecological conditions. Therefore, the objective of this work was to determine the mineral content of ‘Wonderful’ pomegranate leaves for each the nutritional elements and the cation balance, and to establish the nutritional standards using Integrated Differential Diagnosis (IDD). The mineral content of the pomegranate leaves was determined and based on the results, nutritional standards for macro elements, cation balance and microelements were generated through the IDD, which evaluate whether there are mineral and/or physiological imbalances. The macro elements in the cultivation of the pomegranate were the following: NO3 3747.5 µg g-1, Total Nitrogen 1.35%, P 0.14%, K 0.88%, Ca 1.65%, Mg 0.19%, Na 0.006%. For the cation balance, the optimal values ​​were: (Ca+Mg)/K 4.48 mEq 100 g-1, Ca/(K+Mg) 2.13 mEq 100 g-1, Mg/(K+Ca) 0.16 mEq 100 g-1, Ca/Mg 5.06 mEq 100 g-1, K/Mg 1.36 mEq 100 g-1. Finally, the optimal values ​​for the microelements were: Fe 59.5 µg g-1, Mn 31.4 µg g-1, Zn 6.3 µg g-1, Cu 6.1 µg g-1. The values ​​obtained for the micro and macro elements were like those reported. In the case of cation balance and foliar nitrate content, they have not been previously reported. The IDD is a promising and effective auxiliary tool to characterize the nutritional status of pomegranate trees and, in turn, an alternative to conventional methods of nutritional diagnosis with the advantage of establishing a nutritional deficiency (soil-plant relationship) or a physiological imbalance (relation plant - climate) for this crop.

The foliar analysis is a useful tool to detect the nutritional status of plants, predict future problems in the reproductive cycles of fruit production and implement preventive and corrective measures to achieve a mineral balance in fruit trees, obtaining higher productivity. There is little information available on nutrient sufficiency ranges in pomegranate leaf and the literature reported differs due to diverse cultivation practices, cultivars, and agroecological conditions. Therefore, the objective of this work was to determine the mineral content of 'Wonderful' pomegranate leaves for each the nutritional elements and the cation balance, and to establish the nutritional standards using Integrated Differential Diagnosis (IDD). The mineral content of the pomegranate leaves was determined and based on the results, nutritional standards for macro elements, cation balance and microelements were generated through the IDD, which evaluate whether there are mineral and/or physiological imbalances. The macro elements in the cultivation of the pomegranate were the following: NO3 3747.5 µg g-1, Total Nitrogen 1.35%, P 0.14%, K 0.88%, Ca 1.65%, Mg 0.19%, Na 0.006%. For the cation balance, the optimal values were: (Ca+Mg)/K 4.48 mEq 100 g-1, Ca/(K+Mg) 2.13 mEq 100 g-1, Mg/(K+Ca) 0.16 mEq 100 g-1, Ca/Mg 5.06 mEq 100 g-1, K/Mg 1.36 mEq 100 g-1. Finally, the optimal values for the microelements were: Fe 59.5 µg g-1, Mn 31.4 µg g-1, Zn 6.3 µg g-1, Cu 6.1 µg g-1. The values obtained for the micro and macro elements were like those reported. In the case of cation balance and foliar nitrate content, they have not been previously reported. The IDD is a promising and effective auxiliary tool to characterize the nutritional status of pomegranate trees and, in turn, an alternative to conventional methods of nutritional diagnosis with the advantage of establishing a nutritional deficiency (soil-plant relationship) or a physiological imbalance (relation plant - climate) for this crop. [ABSTRACT FROM AUTHOR]

This study is conducted in Muğla Dalaman Agricultural Management Directorate (TİGEM) in 72MAY80 grain and silage maize in the trial area according to purely random trial the randomized complete block design in 3 replications in 2016. The amount of fertilizer is obtained by substracting elements determined by soil analysis from the amount of plant nutrients required for corn yield in -1 in 950 kg. (-1 in 41.5 kg urea). The aim of this research is to determine whether fertilizer application at 4 different rates including the reduction of fertilizer application required for corn yield -1 in 950 kg. by 40% (-1 in 24.95 kg urea) and increasing it by 40% (-1 in 58.1 kg urea) and manufacturer application (-1 in 60 kg urea, -1 in 32,3 kg, 15-15-15 and -1 in 14 kg. KNO3) has an effect on the yield of corn plant and the element content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), boron (B) and molybdenum (Mo) in the leaf. The urea applied to the soil from the base, 15-15-15, fertilizers are given to the band with the sowing seeder. The urea fertilizer used as a top fertilizer in trial plots and KNO3 fertilizer has been applied with drip irrigation system at 3 different times. According to the research results, the effect of applying fertilizer to the soil according to -1 in 950 kg. corn yield, 40% reductions and 40% increases in fertilizer application, and manufacturer application on the yield of corn and the concentration rate of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), boron (B) and molybdenum (Mo) elements in the leaf is found to be statistically significant (p<0.01). The highest yield in corn plant is achieved in the application of manufacturer (-1 in 1.367,0 kg) and the application of increasing the amount of fertilizer by 40% (-1 in 1357.0 kg), fertilizer application according to -1 in 950 kg corn yield (-1 in 1225.3 kg), respectively, whereas, the lowest yield is achieved in the application of reducing the amount of fertilizer by 40% (-1 in 991.0 kg). Moreover, the total amount of fertilizer used in trial plots is calculated according to the fertilizer costs in 2016 and the price spent on fertilizer is determined in Turkish Liras (TL) and this price is divided by the 2016 corn kg price and subtracting the amount of corn obtained from the yield, and net yield is obtained excluding the fertilizer cost. [ABSTRACT FROM AUTHOR]

The correct nutrition of orchards from fertilizer management directly influences fruit yield. Therefore, the objective was to evaluate the nutritional status of orchards of the ‘Montenegrina’ mandarin (Citrus deliciosa Tenore) grafted on Poncirus trifoliata Raf. in southern Brazil. The study included analyzes of soil and leaf tissue from 58 commercial orchards. More than 60% of the orchards were diagnosed with K and Mg insufficiency and more than 30% had an excess of N. There was an insufficiency in Mn and Zn of 60 and 96%, respectively, despite the levels of these micronutrients in the soil being high in both depths studied. In addition, no significant correlations were observed between the contents of a given nutrient in the soil and in the leaves, except for the Ca/Mg ratio. Insufficiency was observed in the leaf contents of K, Mg, Mn and Zn and excesses of N and Cu in the orchards. The use of phosphate and potassium fertilizers requires adjustments due to the excessive content of these nutrients in the soil. Pre-planting acidity correction and soil acidity management in ‘Montenegrina’ mandarin orchards already implanted needs to be optimized. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the nutrient concentration at the foliar level of chrysanthemums grown in tezontle sand using three concentrations of the Steiner Universal Nutrient Solution. Design/Methodology/Approach: A completely randomized design was used, each treatment represented a concentration of the nutrient solution and each concentration had 11 repetitions, the study variables were: foliar concentration of nutrients: N, P, K, Ca, Mg and S, plant height (AP), stem diameter (DT), number of leaves (NH), flower diameter (DF), fresh weight (PF) and dry weight (PS). Results: The results showed this order of extraction K>N>Ca>P>Mg>S, for all concentrations, the foliar N content was low in the three treatments (<3.35%), the P was found in high concentrations. (<0.63%), K was higher in the 100% concentration treatment, Mg (>0.44%) was in sufficient levels, in Ca the 100% concentration had greater absorption and finally the S content was only the adequate in the concentration of 100%, in the morphological variables there were no significant differences. Limitations of the study/Implications: High temperatures helped the proliferation of pests; therefore, it would be good to have a better control of temperatures inside the greenhouse. Findings/Conclusions: Therefore, using different concentrations of the nutrient solution in chrysanthemums grown in tezontle sand affects the nutrient content at the foliar level but not necessarily its morphology. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This publication is intended primarily for Florida sugarcane growers, but it may also be useful to researchers and others interested in sugarcane nutrition. It presents potassium fertilizer recommendations for Florida mineral soils and supporting information. Written by J. Mabry McCray, and published by the UF/IFAS Agronomy Department, September 2022.

Monitoring the nutritional status of the soybean crop, based on nutrient levels in the third trefoil with petiole, can help improve fertilization. The objective of this work was to determine the reference values of macro and micronutrient contents, to evaluate the nutritional status of soybean crops, regarding the degree of balance and to obtain the potential response to fertilization for nutrients. The work was carried out based on a database of foliar nutrient contents and grain yield of soybean crops in Mato Grosso, Campo Novo dos Parecis region, covering different agricultural years, cultivars, soil textures and times of use of the area. with the soybean crop. They were obtained from useful reference values for the evaluation of the nutritional status of soybean crops, regarding the degree of balance, plus limits of nutrient content in the normal range, according to the balance by the Kenworthy method. In low-yield soybean crops in the region studied, on average, for macronutrients, 69.7% of crops are in the normal class, while for micronutrients this percentage is lower, 60.9%. N is the nutrient most found in crops (83.2%), while Cu (49.8%) is the least found in the normal class. Of the low productivity soybean crops studied in this work, 78.3% have adequate nutritional balance. Mg, P and Ca and Cu, Mn and Zn are those for which there are greater expectations of crop productivity gains, in response to fertilization. [ABSTRACT FROM AUTHOR]

Leaf analysis is essential for diagnosing nutritional status and guiding fertilizer application. The present study aimed to investigate the appropriate time for leaf sampling and the effect of genotype on olive nutrition. We determined leaf nutrient concentrations of calcium (Ca), iron (Fe), and manganese (Mn) in five Greek (‘Amfissis’, ‘Chondrolia Chalkidikis’, ‘Koroneiki’, ‘Mastoidis’, and ‘Kalamon’) and one Spanish (‘Picual’) variety from May 2019 to April 2020. The concentrations of Ca, Fe, and Mn were significantly affected by genotype and season. The highest concentrations for all nutrients were determined in April, while the lowest were in May, June, and October. Leaf Ca concentration significantly increased progressively from May to September for all the varieties. Leaves of ‘Koroneiki’ had the highest Ca concentration. Iron concentrations were within the sufficiency thresholds for all the varieties during the whole experimental period, and ‘Mastoidis’ showed the highest concentration. Leaf Mn concentration for all the varieties increased from May to September with an instant decrease in June, apart from ‘Amfissis’. The varieties ‘Kalamon’ and ‘Chondrolia Chalkidikis’ were found to be above the Mn sufficiency threshold throughout the year. Variations among season and genotype depict the complexity of nutrient transportation in leaf tissues. [ABSTRACT FROM AUTHOR]

The experimental work was carried out in the period 2018-2019 in a fruit-bearing peach plantation at the Fruit-Growing Institute – Plovdiv. ‘Glohaven’ cv. grafted on the vegetative rootstock GF 677 was investigated. Increasing doses of three bio-products - Lumbreco, Agriful and Humustim have been tested. The aim of the experiment was to study the influence of bio-products on the main nutrients in the peach leaves. Fertilization with different levels of the bioproducts Lumbreco, Agrifull and Humustim successfully maintained the nutrient supply of the peach leaves. The dose of 1 L/da is recommended for Agriful. For Lumbreco foliar treatment in a dose of 1 L/da as well as combined application (soil (2 L/da) + foliar application (360 ml/da). For Humustim 240 ml/da. The products used can successfully replace the application of chemical fertilizers. [ABSTRACT FROM AUTHOR]

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Analysis of composite pecan leaf samples typically used to determine need for nutrient applications does not account for variability among trees in the sampled area. To account for this unmeasured variability, pecan orchard block nutrient standards are greater than actual single tree nutrient requirements. In 2018 and 2019, we measured variability in a pecan orchard block by evaluating nutrient status of all trees in a study area consisting of two cultivars (Wichita and Western) grafted on open-pollinated ‘Ideal’ seedlings. Foliar zinc (Zn) coefficient of variation (CV) ranged from 0.186 to 0.255 within individual cultivars and years but was as high as 0.30 when combining cultivars within a year. The ‘Western’ cultivar had higher foliar Zn concentrations than ‘Wichita’, but Zn concentrations were not consistently associated with other leaf nutrient levels, soil Zn status, or other soil properties. Using observed foliar Zn variability, we determined that it is necessary to sample 35 trees for a composite sample to achieve a relative margin of error of 10% and 95% confidence level in a pecan orchard block with more than 1000 trees. We developed field scale foliar Zn recommendations based on individual tree research that indicates a minimum acceptable leaf Zn concentration of ≈15 mg·kg–1 is needed to maintain optimal photosynthetic function in Zn chelate fertigated pecan trees. Assuming a Zn CV of 0.30 and a composite sample comprised of leaves from 35 trees, the minimum acceptable orchard block Zn level to ensure that less than 5% of trees had suboptimal levels of Zn was 27.6 mg·kg–1 . An orchard block Zn level below 23.4 mg·kg–1 indicates that more than 5% of trees in the block had suboptimal foliar Zn concentrations. [ABSTRACT FROM AUTHOR]

Cacao crop is under pressure due to the high global consumption of this commodity, a fact that exposes the great need of technical precision for nutritional diagnosis and fertilizer recommendation in the plantations. The objective of this work is to review and to use the available information in the literature and the opinion of the cacao crop experts to establish the Wymore's standardized scoring functions (SSFs) for the main macro and micronutrients in cacao leaves. The critical limits of the SFF of the optimum type were defined for the mineral nutrients N, K, P, Ca, Mg, S, Fe, Zn, Cu, B and Mo, and the SFF "more is better" type was applied for Mn. This SFFs can be used to know the individual status of each nutrient or incorporate linear combination models applied to a system for foliar nutritional diagnosis of the cacao crop. [ABSTRACT FROM AUTHOR]

The present study was carried out to evaluate the leaf nutrient status of commercially grown strawberries in Latvia during 2014–2022. The results of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo and B in 200 strawberry leaf samples from different strawberry-producing farms were analysed over three periods: 2014–2016, 2017–2019, and 2020–2022. According to leaf analyses, plant fertilization was only partly well managed by the growers. During the research period, strawberries in Latvia were generally sufficiently supplied with N, P, K, Mg, Fe, Mn, Mo, and B, while the level of Ca, S, Zn, and Cu was considered low. The deficiency of these nutrients was characteristic for more than 50% of the samples. Since Ca, S, Zn, and Cu are essential for berry formation and quality and contribute to stress resistance; their deficiency could be one of the limiting factors for strawberry yield. The significant positive correlations found between nutrients, including deficient ones, confirmed their close relationship in the uptake process and the importance of sufficient supply. The results clearly indicated that fertilization could currently be an issue that limits the strawberry harvest in Latvia, and adequate provisions of Ca, S, Zn, and B should be the main focus.

Oil palm fertilizer requirements are based on leaflet mineral concentrations. Four oil palm progenies representing a wide genetic diversity of Elaeis guineensis species and with contrasting K and Mg leaflet concentrations were tested in Indonesia and Nigeria, environments which differ predominantly in climate. During 5 years, we compared oil palm progenies' leaflet mineral concentrations between both countries under abundant fertilizer applications to investigate the extent to which they depend on the environment. In the two studied environments, leaflet concentrations significantly differed between progenies for K, Mg and Ca, but the country effect was not found significant (p = 0.352) for any leaflet mineral's concentration. In both countries, progenies ranked similarly in their mineral categories (lowest and highest cation concentrations within the 4 progenies population), indicating that leaflet mineral concentrations in the tested oil palm progenies are mainly determined by their genetic background. For each progeny, with abundant fertilization, K, Mg and Ca proportions to total leaf cation charge (TLCC) were similar, irrespective of the environments in which the palms were cultivated. We have strong indications that foliar concentrations of K, Mg and Ca are determined by genetic factors which dominate the environmental effect. However, it remains uncertain whether differences in oil palm foliar concentrations between different oil palm progenies imply that they require specific fertilizer amounts to attain an optimal production. [ABSTRACT FROM AUTHOR]

Plant-Nitrogen is a vital element that significantly influences plant growth, fruit quality, and yield. However, excessive Nitrogen (N) fertilizer application can have adverse effects on both plant health and environment. Traditional methods of plant-N analysis face numerous challenges like time-consuming procedures, hazardous chemicals, low precision, and limited throughput, hindering efficient and accurate analysis in laboratories. In recent years, Near-Infrared Spectroscopy (NIRS) has emerged as an innovative and rapid method for plant-N analysis, offering non-destructive, cost-effective, and real-time measurements with high accuracy and throughput. This research aimed to explore the potential of utilizing miniaturized handheld Near-Infrared (NIR) sensors in conjunction with machine learning (ML) and chemometrics to assess the N status of tomato plants leaves in the field. Through this study, A comprehensive analysis involving 18 models utilizing different regression and spectral preprocessing methods was conducted. The findings indicate that combining the first- or second-order SG derivatives with the MSC is the optimal spectral data preprocessing method, and that incorporating wavelengths selection techniques, such as GA-PLS and GA-SVM, improves the predictive accuracy of the models by reducing the number of wavelengths considered. The best model's performance was assessed using R2, RMSE, and RPD, yielding values of 81.0–82.8, 7.4–7.8, and 2.3–2.4, respectively. Overall, this study demonstrates that combining NIRS with ML and chemometrics enables effective evaluation of plant-N status using leaves total N content as a proxy variable and emphasizes the significance of integrating spectral preprocessing, modeling, and wavelengths selection techniques to enhance data quality and mitigate the influence of environmental factors that may impact the accuracy of NIRS-based evaluations. • Rapid and efficient method for assessing plant nutritional status was introduced. • Machine learning and chemometrics have unleashed the power of NIR spectroscopy in the analysis of nutrients in fresh leaves. • Leaf diagnosis was a good proxy for evaluating plants nutritional status. • Leaf tissue analysis offered crucial information about the plant status. • Meta-Modeling made it possible to develop powerful calibrations. [ABSTRACT FROM AUTHOR]