Leaf Nutritional Status Research Articles

An evaluation rule to manage productivity properties performance of male date palms

ABSTRACT Male palm trees almost prominently display minute morphological variations; however, date palm growers rely on readily available pollen from unproven male genotypes without giving correct type selection any thought, which may result in low productivity and/or poor fruit quality. This study sought to develop an evaluation rule by calculating an evaluation index for managing the productivity characteristics performance of nine male date palms, which were examined for their pollen productivity, nutritional status and morphological traits from their leaves, pinnae and spathes. The findings showed that the evaluation rule for a male date palm should depend on pollen grains productivity and germination percentage traits with a weight of 5, spathe morphological traits with a weight of 4, pinnae morphological traits with a weight of 3, leaf morphological traits with a weight of 2 and leaf nutritional status with a weight of 1. The best productivity characteristics performance of male date palms was male No. 8 ‘M8’ due to its high evaluation index. The proposed evaluation index criterion will contribute to better information and analytical support for management of the date palm industry to maximise the effectiveness of germplasm conservation and exploitation, as well as procedural and methodological aspects of the analysis.

Ontogeny has a greater effect on defense and leaf nutritional status than fertilization in Stryphnodendron adstringens (Fabaceae)

Investment of plants in defensive and leaf nutritional quality traits may vary with plant ontogeny and the availability of soil nutrients. In this study, we evaluated the effect of ontogeny and soil fertilization on leaf traits of the Brazilian cerrado tree Stryphnodendron adstringens (Fabaceae). Leaf defense traits (total phenolics, condensed and hydrolysable tannins, the number of extrafloral nectaries (EFNs) and the concentration of glucose, sucrose, fructose and total sugar in the extrafloral nectar) and leaf nutritional quality traits (water content, macronutrients, micronutrients and N:P and C:N ratios) were measured in 60 seedlings and 13 reproductive adults that grew in areas with previous P and Ca fertilization over eight years and in neighboring control plots in a Cerrado area in Distrito Federal, Brazil. Sampling was carried out three years after the last application of fertilizer. We found a strong effect of ontogeny on leaf traits: leaves of adult plants were more chemically defended and lower in nutritional quality than those of seedlings. Fertilization modified leaf nutritional quality traits in adults and seedlings, and defense traits in seedlings, increasing the number of EFNs on leaves, total phenolics and condensed tannins. In summary, adult plants of S. adstringens were poor in nutrients and invested more in phenolics and tannins than seedlings, all consistent with plant apparency theory. In contrast, seedlings were much more flexible in their defensive phenotype, with fertilization increasing allocation to total phenolics, condensed tannins and EFN production. This latter result suggests an ability of seedlings to take advantage of very local variation in resources that might increase the likelihood of surviving this vulnerable stage in the life cycle.

Enhancement of bud dormancy release and development, leaf nutrition, flower and fruit quality of kiwifruit cv. ‘Hayward’ induced by BUD 14 biostimulant

The aim of this research was to investigate the influence of a foliar fertilization program, consisted of the BUD 14 nitrogen-calcium commercial formulation (N: 14% w/w, CaO: 5.5% w/w) as a biostimulant, on bud development percentage, flowering rate, classification of flowers into open, closed and triple, flower and pollen quality traits, fruit quality attributes, and leaf nutritional status of the ‘Hayward’ kiwifruit cultivar. The study was realized during a two-year experimental period in Naoussa, Central Macedonia, Greece. The results showed that BUD 14 induced synchronization in bud development relative to different vegetative stages including initiation of bud expansion, appearance of leaf apices covered by hair and deployment of 2-8 leaves and increased the flowering rate of open flowers. Pedicel length, ovary fresh weight, and dry weight, dry matter and length in female flowers as well as maximum pollen grain diameter and area in polar view in male flowers were significantly enhanced in the BUD 14 treatment. Fruit quality characteristics like average weight and dry mass were significantly augmented, and a 1.5-fold and 2-fold increase was recorded in canes length and number of kiwifruits per cane. In addition, leaf nutrient Ca and Mg concentrations were significantly enhanced, compared to the control. The efficacy of BUD 14 as a more target-oriented and environmentally friendly alternative method of supplying plants with smaller and controlled amounts of nutrients for breaking bud dormancy and improving their development was demonstrated, enhancing flower and fruit quality, leaf nutrition, kiwifruit developmental characteristics, and finally the total production per fruit per tree.

Soil warming effects on the transpiration of trees and shrubs in a subtropical secondary forest: A manipulative experiment

The climate warming can increase the productivity of some species while decrease that of others, therefore, knowledge of species-specific responses to warming is helpful to understand the possible trajectory of forest ecosystems. Despite the importance of the subtropical secondary broadleaf forests developed from afforestation in South China, our understanding of how the transpiration of trees and shrubs co-growing in these forests responds to soil warming is limited. To explore the effects of soil warming on transpiration and associated ecophysiological traits of trees and shrubs in wet and dry seasons, as well as to clarify respective contributions of trees and shrubs transpiration to the stand total, we conducted a manipulative experiment of soil warming (+2 ℃, WA) and control (CK) in a subtropical secondary broadleaf forest in South China, and continuously monitored the transpiration (based on sap flow) of trees, Schima superba and Acacia auriculiformis, and that (derived from leaf temperature and microclimate) of shrubs, Psychotria asiatica and Castanopsis chinensis, from 2021 to 2022. We also measured leaf water potentials, leaf nutrient status, and δ13C-derived intrinsic water use efficiency (WUEi). Soil warming did not significantly alter the transpiration of trees, with the exception of A. auriculiformis in 2022, whereas it notably increased transpiration of both shrubs. We attributed the stimulation of shrubs’ transpiration mainly to the more favorable leaf water potentials under warming condition. Due to the increased transpiration, the contribution of shrubs to stand transpiration was consequently increased, highlighting the potential role of shrubs in the hydrological dynamics of forest ecosystems. Additionally, the WUEi, soil main macro-nutrients, and leaf nutritional status of all species were not significantly affected by soil warming. These findings indicated that the carbon-water exchange and nutrient status of the studied plants can be maintained even when exposed to moderate increases in soil temperature and relatively drier condition, reflecting the resilience of the subtropical secondary broadleaf forest to possible climate warming. Further research on the interaction and competition of co-existing trees and shrubs under soil warming will improve the prediction of forest dynamics under future climate change, which benefits the efforts to conserve such forests in order to address the environmental pressure in the region.

Growth Performance of Low Chilling Varieties of Apple (Malus x domestica Borkh.) under the Influence of Different Nutrient Levels in Assam, India

The present investigation was undertaken to evaluate the growth characters and leaf nutrient content of low-chilling apple (Malus x domestica Borkh.) under the effect of different nutrient levels in Assam. Three low-chilling varieties viz. HRMN-99, Dorsett Golden and Anna were grown for this purpose subjected to different nutrients levels comprising of FYM applied alone or in combination with NPK doses. Obtained results revealed that HRMN-99 registered the highest significant plant height (179.76 cm), stem girth (9.91 cm), leaf area (63.34 cm2) and leaf area index (2.42) at the end of season. Amongst various nutrient levels, the application of 5 kg FYM+ 150 g urea+ 210g SSP+ 120 g MOP/plants showed superior performance in terms of plant height (192.03 cm), stem girth (11.30 cm), number of branches (17.25), leaf area (69.38 cm2) and leaf area index (2.61). Analysis of leaf nutritional status revealed that the variety HRMN-99 and nutrient application of 5 kg FYM+ 150 g urea+ 210g SSP+ 120 g MOP/plants showed impressive results in terms of leaf N, P, K, Ca and Mg. Thus, the variety HRMN-99 at nutrient level of 5 kg FYM+ 150 g urea+ 210g SSP+ 120 g MOP/plant proved to be promising for apple cultivation under Assam condition.

Fertilizer Performance of a Digestate from Swine Wastewater as Synthetic Nitrogen Substitute in Maize Cultivation: Physiological Growth and Yield Responses

Nitrogen (N) is the primary nutrient required for plant growth. During the last few decades, there has been extensive use of synthetic N-containing fertilizers in agriculture, resulting in increased environmental pollution. In this study, the feasibility of replacing synthetic N with biofertilizer in maize cultivation was investigated. A liquid biofertilizer (digestate obtained from the anaerobic digestion of swine wastewater) was obtained and applied to large plots as a total (100%) or partial (50%) substitute for synthetic N fertilizer. Moreover, the most efficient fertilization mode, i.e., basal versus foliar application, was studied. Physiological growth indices, leaf nutritional status, and grain yield were assessed for each biofertilization treatment and compared with the conventional treatment with synthetic minerals. Compared with the conventional treatment, the total substitution of synthetic N by the biofertilizer (basal application) did not affect the growth parameters and grain yield of maize; the other treatments usually resulted in lower growth rates and yields, although not statistically significant (p ≥ 0.05). No difference was observed among the treatments for the contents of N, P, K, or Mg in the leaves. Generally, the highest means for Fe, Ca, Cu, Zn, and Mn contents in leaves were observed after in-row broadcast of synthetic fertilizers or basal application of the digestate as a total substitute for synthetic N, with a significant effect for Fe (p < 0.05). The mode of the biofertilizer application did not have any significant effect on either growth parameters or leaf nutrients. The data show that under the specific conditions of the study, the total substitution of mineral N with basal application of biofertilizer is the best strategy for minimizing the use of synthetic chemicals in maize cultivation without yield penalties.

Effect of Some Biostimulants on the Vegetative Growth, Yield, Fruit Quality Attributes and Nutritional Status of Apple

Although the application of chemical fertilizers to crops promotes plant growth and yield, their continuous use affects soil heath and creates environmental pollution. On the other hand, plant biostimulants improve nutrients absorption, plant growth, yield and produce quality and are environment-friendly. Therefore, an experiment was conducted during 2021-22 to evaluate the effect of some biostimulants on the performance of the apple cv. Anna, planted in a sandy loam soil at Marsa Matruh governorate, Egypt. Ninety trees were randomly selected and sprayed with 4 or 6% moringa leaf extract (MLE), 0.3 or 0.4% seaweed extract (SWE), 1000 or 2000 mg L−1 Fulvic acid (FA), 4% MLE + 0.3% SWE + 1000 mg L−1 FA (combination 1), or 6% MLE + 0.4% SWE + 2000 mg L−1 FA (combination 2) before flowering, during full bloom and one month later and compared with a control (untreated trees). The results demonstrated that spraying MLE, SWE or FA or their combinations positively improved the vegetative growth, fruit set %, fruit yield and fruit physical and chemical characteristics as well as leaf nutritional status. The positive effect of MLE, SWE and FA was increased in parallel to an increase in the used concentration of each one of them. The highest increments in the measured parameters were accompanied by the application of combination 2 over the other treatments.

Effect of Organic Manures on Growth, Yield, Leaf Nutrient Uptake and Soil Properties of Kiwifruit (Actinidia deliciosa Chev.) cv. Allison

In recent decades, organic kiwifruit farming has come up as a feasible method for high-quality kiwi production without using chemical fertilizers. The primary objective of this research was to investigate how the sole application of organic and the combined application of organic manures affected the growth, yields, and quality of Allison kiwifruit, as well as the soil's physicochemical characteristics. The field trial was conducted on cv. Allison to determine the efficacy of organic manures (OM) on growth, nutrient absorption, production and soil health. The experiment involved eight treatments, viz.: T1: 100% Dairy manure (DM); T2: 100% Vermicompost (VC); T3: 100% chicken manure (CM); T4: 50% DM + 50% CM; T5: 50% DM + 50% VC; T6: 50% CM + 50% VC; T7: DM + CM + VC in equal proportions; and T8: Recommended nutrients inorganic NPK + 40 kg DM. A randomized complete block design comprising three replicas was used in this investigation. The use of inorganic fertilizers (NPK) in combination with DM enhanced Spad Values Chlorophyll, fruit production, leaf number, leaf area, and stem diameter while also improving the soil's chemical characteristics. The flower initiation was recorded with DM and Vermicompost (50:50). Furthermore, when compared to inorganic fertilizer treatment, OM treatment significantly improved fruit quality by improving fruit chemical composition in terms of soluble solids contents and leaf nutrient status, as well as improving soil's physical properties with DM and Vermicompost (50:50). The study's outcome revealed that OM had a significant impact on flowering time, fruit SSC, leaf nutritional status, and soil physical characteristics. In comparison to organic treatments, recommended fertilizer dosages (NPK + DM) improved plant growth, fruit yield, and soil chemical characteristics.

Soil from Serianthes Rhizosphere Influences Growth and Leaf Nutrient Content of Serianthes Plants

Soils from the rhizosphere of perennial plants accumulate microorganisms that influence the growth of other plants. This microorganism biodiversity may be exploited by using these soils as an inoculum in new planting sites. Soils collected from the rhizosphere of mature Serianthes trees were subjected to treatments designed to reduce or increase microorganism populations, then were used in a series of five studies to grow Serianthes plants in container culture. Serianthes kanehirae and Serianthes grandiflora stem growth was 14–19% greater, leaf nitrogen was 40–46% greater, leaf phosphorus was 50–86% greater, and leaf potassium was 28–43% greater when grown in soils from Serianthes rhizosphere than in soils away from a Serianthes tree. Treating the Serianthes rhizosphere soils with sterilization or propiconazole fungicide reduced stem growth of S. grandiflora, S. kanehirae, and Serianthes nelsonii plants by 16–47% below that of untreated soils. The sterilization and fungicide treatments also consistently reduced phosphorus (48–50%) and potassium (12–21%) content of leaves when compared with untreated rhizosphere soil. Adding Rhizophagus irregularis inoculum to the sterilized soil reversed the reduction in S. grandiflora stem growth and leaf phosphorus content. These findings indicate that soils from the Serianthes rhizosphere contain beneficial microorganisms for Serianthes plant growth and leaf nutritional status and exploiting these soils as an inoculum for new planting sites may provide a net-positive influence on post-transplant growth and survival.

Gerbera leaf nutritional status as a cut flower cultivated with different doses of nitrogen and calcium

Abstract Vegetative tissue analyses might help to diagnose nutritional status of a crop. Foliage diagnosis is an effective method to set up balanced fertilization procedures. The current work aims to evaluate nutrient contents of two gerbera leaf sampling periods as a cut flower cultivated in pots with different doses of nitrogen (N) and calcium (Ca) under greenhouse conditions. The experiment was carried out in a protected environment, shelter type, in a container containing substrate in a 3x3+1 factorial scheme. Three doses of N (0.07, 0.15 or 0.2 g L-1) or three doses of Ca (0.02, 0.03 or 0.04 g L-1) were applied every 15 days. Control plants did receive neither N nor Ca. The substrate was analyzed before and after cultivation, and at the end of production years, as well as completely expanded leaves were collected for nutrient analyses. There was not significant interaction between N and Ca doses. Regarding the sampling period or doses of N and Ca, the determined macronutrient concentrations were in the following order of N>K>Ca>P>S>Mg. The micronutrient concentrations were in the following order of Fe>Mn>B>Zn>Cu. Except for K, all the other nutrient concentrations were in the recommended range for gerberas production.

Nutrient resorption and stoichiometric responses of poplar (Populus deltoids) plantations to N addition in a coastal region of eastern China

Abstract Aims Leaf nutrient resorption is sensitive to changes in soil nutrients. However, the effects of N deposition on nutrient resorption efficiency (NuRE) in plant macro-nutrients remain unclear. Poplar (Populus deltoids) is one of the most extensively cultivated hardwood species worldwide. We explored general patterns and dominant drivers of NuRE and stoichiometry of poplar plantations in response to N addition. Methods We conducted a 4-year N-addition experiment to explore NuRE and stoichiometric responses to N addition in two poplar (P. deltoids) plantations (8- and 12-year-old stands) in a coastal region of eastern China. We measured soil and foliar (green and senesced leaves) concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) for a series of N addition treatments including N0 (0 kg N ha−1 yr−1), N1 (50 kg N ha−1 yr−1), N2 (100 kg N ha−1 yr−1), N3 (150 kg N ha−1 yr−1) and N4 (300 kg N ha−1 yr−1). Important Findings Consistent for (both) 8- and 12-year-old stands, N addition did not affect the NuRE and stoichiometry (with the exception of CaRE and CaRE:MgRE ratio). N resorption efficiency–P resorption efficiency (NRE–PRE) scaling slopes were consistently less than 1.0 under N addition. These results suggest that NRE generally decouples from PRE within each N treatment. Moreover, these results point to robust control of green leaf nutritional status on nutrient resorption processes as indicated by the positive relationships between NuRE and green leaf nutrient concentrations. Our findings provided a direct evidence that growth in 12-year-old poplar plantations was N-limited in the coastal region of eastern China.

Different responses of plant N and P resorption to overgrazing in three dominant species in a typical steppe of Inner Mongolia, China.

Nutrient resorption from senesced leaves is an important mechanism for nutrient conservation in plants. However, little is known about the effect of grazing on plant nutrient resorption from senesced leaves, especially in semiarid ecosystems. Here, we evaluated the effects of grazing on N and P resorption in the three most dominant grass species in a typical steppe in northern China. We identified the key pathways of grazing-induced effects on N and P resorption efficiency. Grazing increased N and P concentrations in the green leaves of Leymus chinensis and Stipa grandis but not in Cleistogenes squarossa. Both L. chinensis and S. grandis exhibited an increasing trend of leaf N resorption, whereas C. squarrosa recorded a decline in both leaf N and P resorption efficiency under grazing. Structural equation models showed that grazing is the primary driver of the changes in N resorption efficiency of the three dominant grass species. For L. chinensis, the P concentration in green and senesced leaves increased the P resorption efficiency, whereas the senesced leaf P concentration played an important role in the P resorption efficiency of C. squarrosa. Grazing directly drove the change in P resorption efficiency of S. grandis. Our results suggest that large variations in nutrient resorption patterns among plant species depend on leaf nutritional status and nutrient-use strategies under overgrazing, and indicate that overgrazing may have indirect effects on plant-mediated nutrient cycling via inducing shifts in the dominance of the three plant species.

Coniferous wood biochar as substrate component of two containerized Lavender species: Effects on morpho-physiological traits and nutrients partitioning

Peat moss continued to be, though the exploitation of peatlands due to the peat extraction, the most important and used growing substrate in the nursery production of containerized ornamental plants. Biochar, the by-product of the pyrolysis technology for bio-energy process from organic feedstocks, has been recently demonstrated a promising replacement substitute for peat in ornamentals production. An experiment was carried out in order to evaluate the differences on growth, ornamental quality and nutrients partitioning of two Lavender species (Lavandula angustifolia and L. dentata) grown in a peat-based growing substrate amended with coniferous wood biochar at 0%, 25 %, 50 % or 75 % (by volume). Increasing biochar content of growing substrates resulted in an increase of several chemical and physical properties such as electrical conductivity, pH, bulk density and total porosity and in a decrease of water retention capacity as well as in nutrients availability (P, Ca and Mg). Higher biochar percentages in the substrate negatively affected growth pattern and physiological traits of the potted plants, due to suboptimal conditions of growing substrates. Lavenders grown with 25 % biochar showed similar growing and qualitative response in terms of number of leaves, root length, biomass production and biomass water use efficiency, compared to those cultivated with 0% biochar, due to an enhanced SPAD index, photosynthetic pigments biosynthesis and leaf nutritional status (higher nitrate, P and K). Overall, our experimental data demonstrated that a peat-based substrate amended with 25 % of coniferous wood biochar could be adopted as a sustainable production system for containerized lavenders, with no negative effects on plant growth and ornamental quality.

Soil and Leaf Nutritional Studies and Status of Healthy and Declined Mandarin Orchards

The present investigation was carried out to determine soil and leaf nutritional status of some typical healthy and declined mandarin orchards of Amravati District (M.S) during 2016-19.Total twenty five representative surface and depth wise soil and leaf samples from healthy and declined mandarin orchards were collected and analyzed various nutrients in plant as well as leaf samples. The data analysis showed that total nitrogen content in healthy and declined mandarin orchards from surface soils varied from 0.045 to 0.093 % and 0.015 to 0.37% respectively. The available nitrogen, phosphorus and potassium content of healthy orchards surface soils varied from 200.0 to 265.7 kg ha-1 , 22.0 to 35.3 kg ha-1 , 320.0 to 665.0 kg ha-1 and in declined orchards it varied from 130.4 to 203.5 kg ha-1 , 17.8 to 21.3 kg ha-1 , 360.0 to 744.4 kg ha-1 respectively. The exchangeable calcium and magnesium together constitute more than 80% of exchange complex. The exchangeable calcium, magnesium and sulphur content in healthy orchards surface soils varied from 26.34 to 30.22 cmol (p+ ) kg ha-1 , 11.71 to 16.92 cmol (p+ ) kg ha-1 , 0.27 to 0.90 kg ha-1 and in declined orchards it varied from 29.00 to 31.98 cmol (p+ ) kg ha-1 , 12.07 to 13.71 cmol (p+ ) kg ha-1 , 0.36 to 0.69 kg ha-1 respectively. Micronutrients status of orange orchards showed that available copper, zinc, iron and manganese in healthy orchards surface soils varied from 2.20 to 5.60 ppm, 0.50 to 0.79 ppm, 4.50 to 6.29 ppm, 12.61 to 18.11 ppm and in declined orchards it varied from 1.90 to 2.48 ppm, 0.35 to 0.46 ppm, 3.40 to 5.00 ppm, 8.10 to 12.24 ppm respectively. Findings revealed that total nitrogen, available nitrogen, phosphorus, sulphur, zinc and manganese content found more supporting in healthy orchards than declined ones. Depth wise distribution showed that total nitrogen, available nitrogen, phosphorus and copper showed decreasing trend with the soil depth. The leaf nutrient content in the plant showed that nitrogen, phosphorus and potassium content in leaf of healthy orchards varied from 2.35 to 2.55%, 0.14 to 0.17%, 0.82 to 1.00% and in declined orchards it varied from 1.75 to 2.00%, 0.10 to 0.13%, and 0.84 to 1.70% respectively. Calcium, magnesium and sulphur content in healthy orchards varied from 3.00 to 3.90%, 0.60 to 0.74%, 0.21 to 0.19% and in declined orchards it ranged from 2.40 to 3.15%, 0.33 to 0.74%, and 0.19 to 0.23% respectively. Results pertaining to micronutrient showed that iron; manganese, copper and zinc in healthy orchards varied from 105.6 to 140.6 ppm, 21.72 to 34.62 ppm, 29.40 to 35.96 ppm, 30.45 to 39.18 ppm, and in declined orchards it varied from 70.66 to 100.00 ppm, 20.38 to 27.67 ppm, 21.72 to 26.05 ppm, and 17.24 to 25.00 ppm respectively. Results showed that a healthy orchard has significantly higher content of nutrient than declined orchards except potassium content

Gypsum Rates and Splitting Under No-Till: Soil Fertility, Corn Performance, Accumulated Yield and Profits

Gypsum is used in agriculture as calcium (Ca2+) and sulfur (S) source, and to mitigate native toxic levels of aluminum (Al3+). However, the effects on soil chemical attributes, corn leaf nutritional status, grain yield, and profitability should be better understood. Gypsum rates (0, 3, 6, 9, and 12 Mg ha−1) were applied at once (2009) or split in two (2009–2010) or three (2009–2010-2011) annual applications, to a Typic Hapludox under no-till from Southern Brazil. The use of gypsum increased Ca2+ and S-SO42− and reduced Al3+ levels in the soil up to 0.8 m depth. Increasing gypsum rates reduced Mg2+ levels up to 0.6 m. Corn leaf concentrations of Ca and S were increased, while Mg concentration was decreased by gypsum use. The maximum technical efficiency (MTE) rate of gypsum for corn (2013/2014) grain yield was 6.34 Mg ha−1. The most profitable rate for the period 2009–2014 growing seasons was achieved with 4.60, 5.63, and 6.08 Mg ha−1 of gypsum applied at once or split in two and three annual applications, respectively. The use of gypsum within the MTE interval improves chemical attributes in the soil profile, corn leaf nutritional status, corn grain yield, and land use profitability. The use of gypsum causes soil Mg2+ leaching. Split application reduces leaching process for S-SO42−, but not for Mg2+.

Evaluation of almond young trees growth and nutritional status under different slow-release compound fertilizer types and doses at Nubaria region

BackgroundSlow-release fertilizers (SRF) are quite numerous, and diverse group of materials are involved in the improvement of the effectiveness of fertilization, mitigation of the negative impact of fertilizers on the environment, and the reduction of labor and energy consumption connected with the application of conventional fertilizers. The objective of the experiment was to measure vegetative growth parameters and nutritional status of Nonpareil almond young trees under two types of slow-release compound fertilizers: Matador at 30, 60, and 120 kg/Feddan and Nitrophoska at (25, 50, and 100 kg/Feddan. The experiment was conducted in the Experimental Research Station of National Research Centre at Nubaria, El Behera governorate, Egypt, during successive growing seasons 2018 and 2019.ResultsThe results indicated that increasing doses of slow-release fertilizer significantly improved vegetative growth of trees. The highest dose of Nitrophoska had significantly higher stem length, diameter, numbers of branches and leaves/trees, leaf area, leaf chlorophyll content, leaf fresh and dry weight while the highest significant of specific leaf dry weight was obtained by applying the highest dose of Matador compared with control trees that received the fast-release fertilizer NPK 19:19:19 at 200 kg/Feddan. Leaf mineral contents of some macro (N, P, K and Mg) and micro elements (Fe, Mn, Zn, and Cu) were significantly increased as a result of application with slow-release fertilizers. Nitrophoska at 100 kg/Feddan gave the highest values of nitrogen, potassium, magnesium, and iron while Matador at 120 kg/Feddan gave the highest value of manganese. Matador at all doses resulted in a significant increment in phosphorus concentration in leaves in both seasons. Nitrophoska at 100 kg/Feddan and Matador at 120 kg/Feddan recorded the highest values of zinc and copper without significant differences between them.ConclusionsIt could be concluded that application with slow-release fertilizers resulted in a positive and significant influence on most investigated vegetative growth measurements and leaf mineral contents of Nonpareil almond trees, since the application with Nitrophoska at 100 kg/Feddan was the most effective treatment for increasing growth measurements and improving leaf nutritional status of Nonpareil almond trees grown under Nubaria condition.

High aluminum concentration and initial establishment of Handroanthus impetiginosus: clues about an Al non-resistant species in Brazilian Cerrado

Cerrado soils are acidic and nutrient-poor, with high content of solubilized Al3+. Plants growing in these conditions may display adaptations to cope with high aluminum concentrations especially during early developmental stages. We investigated leaf nutritional status, and photosynthetic and growth characteristics during the initial establishment of Handroanthus impetiginosus (Mart. Ex Dc.) Mattos, a secondary tree species distributed in the Brazilian Cerrado. Our goal was to understand leaf-level traits related to different aluminum concentrations. H. impetiginosus plants were cultivated in four different aluminum sulfate concentrations: 0, 1, 2, and 4 mM Al, for 40 days. We performed analyses of growth, leaf gas exchange, chloroplast pigment content, and leaf mineral nutrients. We observed a linear increase of Al leaf content as a function of Al concentration in the nutrient solution. Plants grown in 1 mM Al showed a remarkable increase of K leaf content, net photosynthesis, stomatal conductance, and transpiration, while in 4 mM Al there were reductions of N, P, and K contents, gas exchange characteristics, and height. H. impetiginosus did not have mechanisms of avoidance, compartmentalization, or resistance to high Al concentrations. Indeed, this species showed a hormetic response, with low Al concentrations stimulating and high Al concentrations inhibiting plant responses.

High potential of variable rate fertilization combined with a controlled released nitrogen form at affecting cv. Barbera vines behavior

Abstract Variable rate technologies allow site-specific management of parcels characterized by different levels of vigor and/or yield. Fertilization based on actual plant needs is one of the most promising applications of precision farming aiming at improving efficiency, optimizing vine balance, as well as limiting environmental impact. Although this strategy appears suitable for developing new vineyard management models, few experiences validating this hypothesis are available in the literature. Based on a pre-trial remotely sensed vigor map (NDVI-derived, 5 m resolution), a three-year study was performed in a Vitis vinifera L. cv. Barbera vineyard situated in the Colli Piacentini area. Vigor level (L = low, M = medium and H = high) and fertilization technique (Standard, Variable Rate Application, and unfertilized Control) were the main factors in a randomized block design. The controlled release fertilizer Multicote™ Agri ([NPK fertilizer 13-5-21 + 7MgO+14SO3 (Controlled Release Nitrogen >46% on the total nitrogen, with longevity 2÷4 months), low in chloride] was used and the input rate calculated according to the N-supply. For each vigor level the study compared no fertilization (0 kg/ha), standard supply (40 kg of N /ha) and Variable Rate Application (VRA) supply delivering 0, 40 and 80 kg of N/ha to H, M and L, respectively. Vine growth, yield, leaf nutritional status and fruit composition were assessed. Results show that the classified L vigor plots had significantly less growth (i.e leaf area or pruning weight per vine) than M and H vigor plots, whereas yield components and grape composition followed a linear variation with vigor. There was a large prevalence of vigor x technique interactions suggesting that VRA had a differential impact on vine behavior depending upon the initial level of vigor. For vegetative and yield parameters, in the L vigor vines, increased Multicote™ Agri dosage delivered as control (0 kg of N/ha), standard (40 kg of N/ha) and VRA (80 kg of N/ha) caused a very close and linear increase in total leaf and yield per vine, whereas, within the M and H vigor plots, the effect due to fertilization technique was very mild. Such a behavior was nicely mirrored by grape composition at harvest as, in L vines, applying 40 or 80 kg of N in the form of Multicote™ Agri induced a progressive and significant reduction in both must soluble solids and total anthocyanins concentration, although the oenological quality of the resulting must was still satisfactory and in compliance with the oenological target. The novelty of the present work is that, unlike previous variable rate fertilization attempts where a rapid nitrogen release fertilizer such as urea was used, L vigor vines showed a very prompt response to the amount of Multicote™ Agri application, confirming higher effectiveness of this chemical form and higher flexibility in adjusting the level of vigor and yield according to specific needs. Conversely, when the initial level of vigor was medium or high, differential fertilization resulted in overall minor modifications of the vine behavior.

Effects of Variable Rate Nitrogen Application on cv. Barbera Performance: Yield and Grape Composition

This paper follows a first contribution on the long-term effects of variable rate nitrogen application on vegetative growth and leaf nutritional status of a small Barbera vineyard, where three vigor levels classified as low, medium, and high (L, M, H) were identified pretrial from normalized difference vegetation index (NDVI) values determined by remotely sensed imagery (5 megapixel resolution). Variable rate fertilization supplying no N (0 kg/ha; C), standard rate (60 kg/ha; S), and variable rate application (VRA) of 60 or 120 kg/ha to H, M, and L over four consecutive seasons showed that variability among vigor levels was significantly reduced in years three and four, while mean effects related to fertilization strategy were not significant. In this companion paper, L vines were most balanced, suggesting a change in fertilization strategy to no N application in M and H areas, and for maintenance supply in L plots. However, significant vigor level × year interactions indicated that within-vigor variability for total yield and berry weight was considerably reduced, while concomitant seasonal accumulations of sugar and color in 2014 and 2015 were much less variable within dates across vigor levels, suggesting the efficacy of the VRA approach. While the main effects of fertilization supply were mostly non-significant, seasonal accumulation of total soluble solids and anthocyanins in 2014 and 2015 showed that plots receiving 60 kg N/ha had lower within-date values than C (no N), suggesting increasing sensitivity over years. However, the L vines had an almost negligible response to increased N supply, and most observed responses were primarily due to reduced vine capacity.

Behavior of leaf nutritional status in ‘on’ and ‘off’ year bearing trees of ‘Bengal’ litchi (Litchi chinensis)

The major problems reported in litchi in several countries include irregular flowering, poor fruit retention, small fruit size and alternate bearing. This study assessed the time course (all-year-round, on a monthly basis) of the leaf macro- and micronutrient concentrations, in ‘on’ and ‘off’ year bearing ‘Bengal’ litchi trees. In December 2012, fifty uniform trees, half of them with a heavy fruit load (‘on’ year) and the other half with a very light crop load (‘off’ year) were tagged to trace their nutritional status. The trees were twelve years old, with an approximately 5 m canopy diameter and 4 m in height, and have received the same cultural practices and fertilization since the orchard establishment. Leaves were sampled monthly from December 2012 to November 2013 and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron (B). Data were submitted to analysis of variance and means compared by multiple range test at 5% probability. Leaf analysis showed differences between ‘on’ and ‘off’ year bearing trees for N, K, Mn and Cu. Leaf macronutrients were higher in the 4th month and lower around the 10th month, whereas leaf micronutrients were higher around the10th month and lower in the 4th month. These results open the possibility to use leaf analysis as a tool to predict potential yield and manage fertilization accordingly to minimize alternate bearing in litchi.