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12 pages, 939 KiB

Open AccessArticle

Use of a Biostimulant to Mitigate Salt Stress in Maize Plants

by Roberto D’Amato and Daniele Del Buono

Agronomy 2021, 11(9), 1755; https://doi.org/10.3390/agronomy11091755 - 31 Aug 2021

Cited by 14 | Viewed by 3723

Abstract

Salinity is considered among the abiotic stresses most impacting agriculture for its ability to interfere with crop development and quality. For this reason, practices and innovations that could contain the deleterious effects of such stress are of pivotal importance for maintaining acceptable crop [...] Read more.

Salinity is considered among the abiotic stresses most impacting agriculture for its ability to interfere with crop development and quality. For this reason, practices and innovations that could contain the deleterious effects of such stress are of pivotal importance for maintaining acceptable crop yields. In this context, this work has concerned the study of severe salt stress (100 mM NaCl) on maize seedlings and the effects of a plant biostimulant (Megafol–Meg) in helping plants to cope with this adversity. Biomass production, pigments, the content Na⁺ and K⁺, the accumulation of hydrogen peroxide (H₂O₂) and lipid peroxidation products (MDA), total phenolic compounds (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) were investigated in control samples, in samples treated with NaCl alone, and in samples treated with NaCl in combination with the biostimulant. The results showed that the biostimulant significantly mitigated the impact of the salt stress on shoot length and fresh weight, on chlorophyll and carotenoid contents, and reduced the amount of Na⁺ taken up by the species. Regarding the oxidative status, the biostimulated samples revealed lower amounts of H₂O₂ and MDA, while maize seedlings grown with NaCl alone exhibited the highest increases in the TPC, ABTS, and FRAP. The explanation for these effects is provided by highlighting the effectiveness of the biostimulant in avoiding Na⁺ accumulation, which resulted in a lower content of H₂O₂, MDA, TPC, and antioxidant activity. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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18 pages, 2619 KiB

Open AccessArticle

Enhancement in Bell Pepper (Capsicum annuum L.) Plants with Application of Roholtiella sp. (Nostocales) under Soilless Cultivation

by Adewale Suraj Bello, Imen Saadaoui, Talaat Ahmed, Helmi Hamdi, Maroua Cherif, Tasneem Dalgamouni, Ghamza Al Ghazal and Radhouane Ben-Hamadou

Agronomy 2021, 11(8), 1624; https://doi.org/10.3390/agronomy11081624 - 16 Aug 2021

Cited by 11 | Viewed by 3651

Abstract

Cyanobacteria are found to be renewable and sustainable additives for growth improvement in crops. Extracts and biomass of three nitrogen-fixing cyanobacteria namely, Roholtiella sp. (QUCCCM97), Nostoc ellipsosporum (QUCCCM99), and Desmonostoc danxiaense (QUCCCM112) isolated from Qatar desert environment were tested for their ability to [...] Read more.

Cyanobacteria are found to be renewable and sustainable additives for growth improvement in crops. Extracts and biomass of three nitrogen-fixing cyanobacteria namely, Roholtiella sp. (QUCCCM97), Nostoc ellipsosporum (QUCCCM99), and Desmonostoc danxiaense (QUCCCM112) isolated from Qatar desert environment were tested for their ability to enhance the growth of bell pepper (Capsicum annuum L.) seedlings. Soilless cultivation experiments were carried out by applying the biomass and the aqueous extract of the three cyanobacteria separately. Seedlings were transplanted to Hoagland’s solution under regulated conditions. In total, 2, 4, and 6 mL L⁻¹ of the three microalgae extract as well as 1 and 2 mg L⁻¹ of the three microalgae biomasses (as biofertilizer) were added to the Hoagland solution. An assessment of seedling growth parameters such as shoot length, root length, fresh weight, dry weight, spad index, number of leaves per plant, and growth rate was performed. However, among the different doses and concentrations of investigated QUCCCM97, 99, and 112, our findings revealed that shoot length (cm), root length (cm), fresh weight (g), the number of leaves per plant, and growth rate were positively affected and significantly increased at maximum dose/concentration compared to control plants. With QUCCCM97, shoot length, root length, fresh weight, the number of leaves, and the growth rate increased by 17.5%, 40.3%, 26.0%, 21.6%, and 22.8%, respectively, compared to the control. Additionally, with QUCCCM99, the same parameters increased by 12.3%, 25.3%, 15.1%, 9.3%, 51.8%, respectively. While in presence of QUCCCM112, they increased by 8.7%, 30.1%, 15.6%, 5.4%, 48.6%, respectively. Our results demonstrated that extracts and biomass of cyanobacteria strains investigated here, and particularly Roholtiella sp. (Nostocales), have an enhancement potential of the seedling growth and could be used in modern agriculture to enhance productivity under the soilless system and ensure sustainability. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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14 pages, 1870 KiB

Open AccessEditor’s ChoiceArticle

Consortia of Plant-Growth-Promoting Rhizobacteria Isolated from Halophytes Improve Response of Eight Crops to Soil Salinization and Climate Change Conditions

by Susana Redondo-Gómez, Jennifer Mesa-Marín, Jesús A. Pérez-Romero, Javier López-Jurado, Jesús V. García-López, Vicente Mariscal, Fernando P. Molina-Heredia, Eloisa Pajuelo, Ignacio D. Rodríguez-Llorente, Timothy J. Flowers and Enrique Mateos-Naranjo

Agronomy 2021, 11(8), 1609; https://doi.org/10.3390/agronomy11081609 - 13 Aug 2021

Cited by 34 | Viewed by 4410

Abstract

Soil salinization is an environmental problem that adversely affects plant growth and crop productivity worldwide. As an alternative to the conventional approach of breeding salt-tolerant plant cultivars, we explored the use of plant-growth-promoting rhizobacteria (PGPR) from halophytic plants to enhance crop growth under [...] Read more.

Soil salinization is an environmental problem that adversely affects plant growth and crop productivity worldwide. As an alternative to the conventional approach of breeding salt-tolerant plant cultivars, we explored the use of plant-growth-promoting rhizobacteria (PGPR) from halophytic plants to enhance crop growth under saline conditions. Here, we report the effect of five PGPR consortia from halophytes on the growth of eight (alfalfa, flax, maize, millet, rice, strawberry, sunflower, and wheat) of the crops most commonly produced on salinized soils worldwide. To test the efficiency of halotolerant consortia, we designed a complex environmental matrix simulating future climate-change scenarios, including increased CO₂ levels and temperature. Overall, biofertilizers enhanced growth of most crops with respect to non-inoculated control plants under different CO₂ concentrations (400/700 ppm), temperatures (25/+4 °C), and salinity conditions (0 and 85 mM NaCl). Biofertilizers counteracted the detrimental effect of salinity on crop growth. Specifically, strawberry and rice showed the greatest positive additive response to inoculation in the presence of salt; above-ground biomasses were 35% and 3% greater, respectively, than their respective control grown without salt. Furthermore, depending on the interaction of environmental factors (salinity × CO₂ × temperature) analyzed, the results varied—influencing the most effective biofertilizer determined for each crop now, or in the future. Our findings highlight the importance of conducting studies that consider stress interaction for realistic assessments of the potential of biofertilizers in a climate-changed world. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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18 pages, 2490 KiB

Open AccessEditor’s ChoiceArticle

Enhancing the Quality of Two Species of Baby Leaves Sprayed with Moringa Leaf Extract as Biostimulant

by Stefania Toscano, Antonio Ferrante, Ferdinando Branca and Daniela Romano

Agronomy 2021, 11(7), 1399; https://doi.org/10.3390/agronomy11071399 - 12 Jul 2021

Cited by 28 | Viewed by 3988

Abstract

Natural biostimulants obtained by plants are intensively used nowadays to improve crop yield and quality. The current study aimed to evaluate the effects of leaf extract of moringa (Moringa oleifera Lam.) (MLE) in modifying baby leaf characteristics of two genotypes of Brassica. [...] Read more.

Natural biostimulants obtained by plants are intensively used nowadays to improve crop yield and quality. The current study aimed to evaluate the effects of leaf extract of moringa (Moringa oleifera Lam.) (MLE) in modifying baby leaf characteristics of two genotypes of Brassica. The trial was started in October 2020 in a greenhouse; a cultivar of kale ‘Cavolo Laciniato Nero di Toscana’ (CL) and a Sicilian landrace of sprouting broccoli ‘Broccoli Nero’ (BN) were used. The plants, after 15, 30 and 40 days from sowing, were treated with MLE, while the control plants (C) with distilled water. Treatment with MLE modified morphological and nutritional value, but with different behavior in the two genotypes. In fact, in BN the treatment reduced the antioxidant activity (2.2-diphenyl-1-picrylhydrazyl (DPPH)) by 54%, while in CL the treatment increased this parameter by 40%. For the phenolic concentration and the sugar content the values recorded were significantly increased by MLE compared to control plants in CL, where in BN a significant reduction was registered. The CL plants treated with MLE showed a significant reduction (−70%) in nitrate content compared to the control plants; a negative effect was, instead, observed in BN, where the plants treated with moringa showed an increase of 60%. Results of this study showed how the foliar application of MLE was effective in improving various nutraceutical parameters, in particular in kale, because it appears to be a species-specific response. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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12 pages, 1342 KiB

Open AccessArticle

Extracts of Emmer Wheatgrass Grown with Distilled Water, Salinity or Selenium Differently Affect Germination and Cytosolic Ca²⁺ of Maize Pollen

by Alberto Marco Del Pino, Beatrice Falcinelli, Roberto D’Amato, Daniela Businelli, Paolo Benincasa and Carlo Alberto Palmerini

Agronomy 2021, 11(4), 633; https://doi.org/10.3390/agronomy11040633 - 26 Mar 2021

Cited by 3 | Viewed by 2085

Abstract

In this work, the biological activity of emmer (Triticum turgidum L. spp. dicoccum (Schrank ex Shubler) Thell.) wheatgrass extracts obtained from grains sprouted with distilled water, or salinity (50 mM) or selenium (45 mg L⁻¹ of Na₂SeO₃), [...] Read more.

In this work, the biological activity of emmer (Triticum turgidum L. spp. dicoccum (Schrank ex Shubler) Thell.) wheatgrass extracts obtained from grains sprouted with distilled water, or salinity (50 mM) or selenium (45 mg L⁻¹ of Na₂SeO₃), was tested through an experimental biological model based on the germination and cytosolic Ca²⁺ homeostasis of maize pollen grains. The effects of thapsigargin (TG) and of four phenolic acids (PAs: ferulic, coumaric, salicylic and 3-HO benzoic) on maize pollen were also tested as controls. Wheatgrass extracts influenced both pollen cytosolic Ca²⁺ and germination. The Ca²⁺ agonist activity of emmer wheatgrass was transient, different from that of TG, which caused a depletion of the stored Ca²⁺ and a permanent alteration of Ca²⁺ homeostasis. The results obtained with extracts compared to those obtained with pure PAs suggest that PAs in unconjugated forms, which are known to be well represent in emmer wheatgrass, contribute to the biological activity of extracts. The extent of the biological response of emmer wheatgrass extracts was influenced by emmer sprouting conditions (i.e., distilled water, or salinity or selenium). Maize pollen treated with Se-enriched wheatgrass extracts showed a less perturbed cytosolic Ca²⁺ and a higher germination rate. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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11 pages, 1958 KiB

Open AccessArticle

Effect of a Biostimulant on Bermudagrass Fall Color Retention and Spring Green-Up

by Verónica De Luca and Diego Gómez de Barreda

Agronomy 2021, 11(3), 608; https://doi.org/10.3390/agronomy11030608 - 23 Mar 2021

Cited by 3 | Viewed by 2275

Abstract

Field research was conducted in 2017–2019 on “Princess 77” bermudagrass (Cynodon dactylon (L.) Pers.) to determine whether an amino acid based biostimulant program applied in the late season (October-November) and early season (March-April) could extend fall color retention (FCR) or hasten the [...] Read more.

Field research was conducted in 2017–2019 on “Princess 77” bermudagrass (Cynodon dactylon (L.) Pers.) to determine whether an amino acid based biostimulant program applied in the late season (October-November) and early season (March-April) could extend fall color retention (FCR) or hasten the spring green-up (SGU), respectively. Bermudagrass was treated with the biostimulant under five different managements: non-treated; 6 times at 5 L ha⁻¹ weekly; 3 times at 5 L ha⁻¹ in a 14-day interval; 6 times at 10 L ha⁻¹ weekly; and 3 times at 10 L ha⁻¹ in a 14-day interval. Normalized difference vegetation index (NDVI) and visual ratings (turf green color and percentage of green coverage in the subplot) were determined weekly, and turf clipping dry weight for the SGU studies. At the end of the FCR studies (2017 and 2018), there was no effect of the biostimulant; although, some isolated positive effects were detected during the experiment in 2017 on bermudagrass treated weekly at 10 L ha⁻¹ for NDVI. However, there was a slight positive effect on SGU when this physiological process occurred slowly (year 2018) and the biostimulant was applied weekly at 10 L ha⁻¹ (4.4 kg N ha⁻¹), compared to another performed management and warmer years (2017 and 2019). Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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18 pages, 2474 KiB

Open AccessArticle

Foliar Micronutrient Application for High-Yield Maize

by Zachary P. Stewart, Ellen T. Paparozzi, Charles S. Wortmann, Prakash Kumar Jha and Charles A. Shapiro

Agronomy 2020, 10(12), 1946; https://doi.org/10.3390/agronomy10121946 - 11 Dec 2020

Cited by 10 | Viewed by 3189

Abstract

Nebraska soils are generally micronutrient sufficient. However, critical levels for current yields have not been validated. From 2013 to 2015, 26 on-farm paired comparison strip-trials were conducted across Nebraska to test the effect of foliar-applied micronutrients on maize (Zea mays L.) yield [...] Read more.

Nebraska soils are generally micronutrient sufficient. However, critical levels for current yields have not been validated. From 2013 to 2015, 26 on-farm paired comparison strip-trials were conducted across Nebraska to test the effect of foliar-applied micronutrients on maize (Zea mays L.) yield and foliar nutrient concentrations. Treatments were applied from V6 to V14 at sites with 10.9 to 16.4 Mg ha⁻¹ yield. Soils ranged from silty clays to fine sands. Soil micronutrient availability and tissue concentrations were all above critical levels for deficiency. Significant grain yield increases were few. Micronutrient concentrations for leaf growth that occurred after foliar applications were increased 4 to 9 mg Zn kg⁻¹ at 5 of 17 sites with application of 87 to 119 g Zn ha⁻¹, 12 to 16 mg kg⁻¹ Mn at 2 of 17 sites with application of 87 to 89 g Mn ha⁻¹, and an average of 8.1 mg kg⁻¹ Fe across 10 sites showing signs of Fe deficiency with application of 123 g foliar Fe ha⁻¹. Foliar B concentration was not affected by B application. Increases in nutrient concentrations were not related to grain yield responses except for Mn (r = 0.54). The mean, significant grain yield response to 123 g foliar Fe ha⁻¹ was 0.4 Mg ha⁻¹ for the 10 sites with Fe deficiency symptoms. On average, maize yield response to foliar Fe application can be profitable if Fe deficiency symptoms are observed. Response to other foliar micronutrient applications is not likely to be profitable without solid evidence of a nutrient deficiency. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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21 pages, 4198 KiB

Open AccessArticle

Foliar Mineral Treatments for The Reduction of Melon (Cucumis melo L.) Fruit Cracking

by Alvaro Lopez-Zaplana, Gloria Bárzana, Agatha Agudelo and Micaela Carvajal

Agronomy 2020, 10(11), 1815; https://doi.org/10.3390/agronomy10111815 - 19 Nov 2020

Cited by 13 | Viewed by 4117

Abstract

Fruit cracking affects many types of crops and is a major problem since the breakage of the surface of the fruit produces high economic losses. Numerous studies have looked at different ways to prevent this, mainly in melon, but with a low success [...] Read more.

Fruit cracking affects many types of crops and is a major problem since the breakage of the surface of the fruit produces high economic losses. Numerous studies have looked at different ways to prevent this, mainly in melon, but with a low success rate. In this work, a standardisation of the induction of cracking is proposed that involves changes in the irrigation pattern (high conductivity or double irrigation). The prevention of the appearance of cracking was carried out through different foliar mineral treatments. The incidence of cracking was studied in relation to gas exchange variables and the concentrations of minerals in tissues. Our results show a more pronounced increase in cracking with double irrigation. Multiple elements were found to be associated with cracking such as B, Ca, K, Mg, Mn, Na, P, and Zn. Furthermore, foliar application of different microelements (B, Cu, Fe, Mn, Mo, and Zn) decreased the melon cracking incidence, thus assigning to the appropriate combination of these elements a crucial role in cracking amelioration. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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11 pages, 259 KiB

Open AccessArticle

Micronutrient Foliar Fertilization for the Biofortification of Raw and Minimally Processed Early Potatoes

by Anita Ierna, Alessandra Pellegrino, Rosario Paolo Mauro and Cherubino Leonardi

Agronomy 2020, 10(11), 1744; https://doi.org/10.3390/agronomy10111744 - 10 Nov 2020

Cited by 8 | Viewed by 2938

Abstract

Agronomic fortification with microelement as well as macronutrients has been used in recent years with increasing frequency to improve the nutritional quality of plant products for human consumption. Here the influence of pre-harvest foliar micronutrients fertilization (Micro+) including B, Cu, Fe, Mn, Mo [...] Read more.

Agronomic fortification with microelement as well as macronutrients has been used in recent years with increasing frequency to improve the nutritional quality of plant products for human consumption. Here the influence of pre-harvest foliar micronutrients fertilization (Micro+) including B, Cu, Fe, Mn, Mo and Zn compared to control (Micro−) on mineral profiles of raw and minimally processed potatoes of cv. Bellini was investigated. The mineral profile was analyzed on raw tubers at harvest and on minimally processed potatoes after 0 and 12 days of storage at 4 ± 1 °C. Preliminary results showed that micronutrients fertilization improved mineral composition of raw potatoes, through an increase in tuber concentrations of Fe (+70%) and Zn (+27%), but also of N (+23%), and Mn (+18%). The increased concentrations of minerals in micro-fertilized raw potatoes led to a better concentration in micro-fertilized minimally processed potatoes, even if some minerals were lost in processing, presumably due to skin removal. The reduction was particularly evident in both Micro– and Micro+ samples for Fe (−29%) and Ca (−17%). However foliar micronutrient fertilization markedly improved the Fe and Zn contribution that a 200 g serving of potatoes can give to current recommended nutrient intakes (RNIs) both in raw and minimally processed potatoes. Storage for 12 days did not alter the mineral profile of the tubers. Observations of the mineral profiles of the studied samples suggest that the application of foliar microelement-containing solutions was able to fortify both raw and minimally processed potatoes. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

21 pages, 6343 KiB

Open AccessArticle

Foliar Application of Zn Alleviates Salt Stress Symptoms of Pak Choi Plants by Activating Water Relations and Glucosinolate Synthesis

by Hamideh Fatemi, Micaela Carvajal and Juan José Rios

Agronomy 2020, 10(10), 1528; https://doi.org/10.3390/agronomy10101528 - 8 Oct 2020

Cited by 14 | Viewed by 3038

Abstract

Several studies have related the application of micronutrients such as zinc, iron and molybdenum with alleviation of stress symptoms in horticultural plants. However, there are few studies that correlate the microelements with water relations. The main objective of this study was to determine [...] Read more.

Several studies have related the application of micronutrients such as zinc, iron and molybdenum with alleviation of stress symptoms in horticultural plants. However, there are few studies that correlate the microelements with water relations. The main objective of this study was to determine the effect of the foliar application of Zn on pak choi (Brassica campestris, L.) plants grown under saline conditions. When plants were grown in a nutrient solution containing 0 or 80 mM NaCl, shoot biomass was greatly decreased, while, in a separate experiment, Zn toxicity was observed when it was applied at concentrations above 50 µM as a foliar spray. In a third experiment, low Zn applications, mainly 25 µM, enhanced parameters such as gas exchange, biomass and glucosinolates synthesis in plants grown under saline conditions (80 mM NaCl). Also, Zn application provoked a rise in membrane integrity and decreased oxidative damage in root cells. In conclusion, Zn application decreased oxidative damage and increased the content of glucosinolates, which could act as important signals to improve water uptake and transport and, as a consequence, alleviate salinity stress in pak choi plants. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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24 pages, 9293 KiB

Open AccessEditor’s ChoiceArticle

Stomata and Xylem Vessels Traits Improved by Melatonin Application Contribute to Enhancing Salt Tolerance and Fatty Acid Composition of Brassica napus L. Plants

by Ibrahim A. A. Mohamed, Nesma Shalby, Ali M. A. El-Badri, Muhammad Hamzah Saleem, Mohammad Nauman Khan, Muhammad A. Nawaz, Meng Qin, Ramadan A. Agami, Jie Kuai, Bo Wang and Guangsheng Zhou

Agronomy 2020, 10(8), 1186; https://doi.org/10.3390/agronomy10081186 - 13 Aug 2020

Cited by 80 | Viewed by 5869

Abstract

Salinity stress is a limiting factor for the growth and yield quality of rapeseed. The potentiality of melatonin (MT; 0, 25, 50, and 100 µM) application as a seed priming agent in mediating K⁺/Na⁺ homeostasis and preventing the salinity stress [...] Read more.

Salinity stress is a limiting factor for the growth and yield quality of rapeseed. The potentiality of melatonin (MT; 0, 25, 50, and 100 µM) application as a seed priming agent in mediating K⁺/Na⁺ homeostasis and preventing the salinity stress mediated oxidative damage and photosynthetic inhibition was studied in two rapeseed cultivars. We found that 50 µM MT treatment imparted a very prominent impact on growth, metabolism of antioxidants, photosynthesis, osmolytes, secondary metabolites, yield, and fatty acids composition. Days required for appearance of first flower and 50% flowering were decreased by MT application. Exogenous MT treatment effectively decreased the oxidative damage by significantly declining the generation of superoxide and hydrogen peroxide under saline and non-saline conditions, as reflected in lowered lipid peroxidation, heightened membrane stability, and up-regulation of antioxidant enzymes (catalase, superoxide dismutase, and ascorbate peroxidase). Furthermore, MT application enhanced the chlorophyll content, photosynthetic rate, relative water content, K⁺/Na⁺ homeostasis, soluble sugars, and proline content. Moreover, MT application obviously improved the oil quality of rapeseed cultivars by reducing glucosinolates, saturated fatty acids (palmitic and arachidic acids), and enhancing unsaturated fatty acids (linolenic and oleic acids except erucic acid were reduced). Yield related-traits such as silique traits, seed yield per plant, 1000 seeds weight, seed oil content, and yield biomass traits were enhanced by MT application. The anatomical analysis of leaf and stem showed that stomatal and xylem vessels traits are associated with sodium chloride tolerance, yield, and seed fatty acid composition. These results suggest the supportive role of MT on the quality and quantity of rapeseed oil yield. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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12 pages, 740 KiB

Open AccessArticle

Betaine Hydrochloride Treatment Affects Growth and Phenylpropanoid Accumulation in Tartary Buckwheat (Fagopyrum tataricum) Seedlings under Salt Stress

by Min Cheol Kim, Nam Su Kim, Yeon Bok Kim, Chul Min Kim, Yong Suk Chung and Sang Un Park

Agronomy 2020, 10(6), 906; https://doi.org/10.3390/agronomy10060906 - 25 Jun 2020

Cited by 3 | Viewed by 3601

Abstract

Betaine is one of the most competitive compounds that accumulate in different cellular compartments to adjust osmotic balance. Among the various stressors, salinity stress often leads to osmotic and ionic stress in plants, either increasing or decreasing certain secondary plant metabolites. In this [...] Read more.

Betaine is one of the most competitive compounds that accumulate in different cellular compartments to adjust osmotic balance. Among the various stressors, salinity stress often leads to osmotic and ionic stress in plants, either increasing or decreasing certain secondary plant metabolites. In this study, different concentrations of NaCl, betaine, and combined NaCl and betaine were used in time-course experiments to investigate growth pattern variation and accumulation of phenylpropanoid compounds in buckwheat sprouts. A significant increase in growth was observed with the application of 0.1–1.0 mM betaine. Although overall, the total phenylpropanoid compounds were lower compared to the control, the sole application of 50 mM NaCl and 1.0 mM betaine especially enhanced the accumulation of some of these compounds in comparison to others. Betaine application at lower concentrations was found to enhance the growth of buckwheat sprouts slightly. The results of this study show that phenylpropanoid content did not increase significantly in any of the treatments. However, it was proven that the phenylpropanoid biosynthetic pathway is stimulated under abiotic stress, resulting in a higher accumulation of various phenylpropanoid compounds. This suggests that the level of accumulation of phenylpropanoid compounds due to abiotic stress may be species-dependent. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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12 pages, 3057 KiB

Open AccessArticle

Evaluation of the Effects of the Application of Glauconitic Fertilizer on Oat Development: A Two-Year Field-Based Investigation

by Maxim Rudmin, Santanu Banerjee and Boris Makarov

Agronomy 2020, 10(6), 872; https://doi.org/10.3390/agronomy10060872 - 18 Jun 2020

Cited by 17 | Viewed by 4744

Abstract

This study explores the fertilizer potential of glauconitic soil by monitoring its impact on the growth of plants during the second growing season after application. Our study documents a higher growth of oats (Avena sativa) in glauconitic amended soil compared to [...] Read more.

This study explores the fertilizer potential of glauconitic soil by monitoring its impact on the growth of plants during the second growing season after application. Our study documents a higher growth of oats (Avena sativa) in glauconitic amended soil compared to that recorded with the control sample at the end of a 97-day-long experiment. Concentrations of nutrients (K, P, ammonium, Ca, Mg) and pH of the soil increase sharply in the first growing season and mildly thereafter, after an initial concentration of 200 g·m⁻² glauconite (equivalent to 2 t·ha⁻¹). The pH of the glauconitic-amended soil increases from an initial 6.0 to 6.34 during the second season. Organic matter and nitrates decrease in the soil mixture at the end of the second growing season, while the exchangeable ammonium increases. Organic acids promote the mobility and bioavailability of nutrients in the soil. Glauconitic soil is particularly effective for weakly acidic soils with a low moisture content. The steady increase in total yield and plant height, and the slow-release of nutrients during the second growing season indicates that glauconitic soil can be an effective and eco-friendly fertilizer. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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10 pages, 270 KiB

Open AccessArticle

Early Season Foliar Iron Fertilization Increases Fruit Yield and Quality in Pomegranate

by Sohrab Davarpanah, Ali Tehranifar, Mahvash Zarei, Mehdi Aran, Gholamhossein Davarynejad and Javier Abadía

Agronomy 2020, 10(6), 832; https://doi.org/10.3390/agronomy10060832 - 12 Jun 2020

Cited by 17 | Viewed by 4318

Abstract

Early season foliar fertilization with different nutrients is a promising tool in pomegranate grown in poor, high pH soils. The effects of foliar fertilization with FeSO₄ and the synthetic chelate Fe(III)-EDDHA (Fe(III)-ethylendiaminedi(o-hydroxyphenylacetate)) on fruit yield and physicochemical characteristics were assessed in a [...] Read more.

Early season foliar fertilization with different nutrients is a promising tool in pomegranate grown in poor, high pH soils. The effects of foliar fertilization with FeSO₄ and the synthetic chelate Fe(III)-EDDHA (Fe(III)-ethylendiaminedi(o-hydroxyphenylacetate)) on fruit yield and physicochemical characteristics were assessed in a two-season field trial. Fertilizers were sprayed at full bloom and one month later, using Fe concentrations of 1.3 and 2.6 mM for FeSO₄ and 1.1 and 2.1 mM for the Fe-chelate. Both doses of FeSO₄ and the higher chelate dose increased leaf Fe concentrations and fruit yield, with the best results being observed with 2.6 mM FeSO₄ (20–31% increases in yield). On the other hand, leaf N, P, K, Ca, and Mn concentrations were not affected by foliar Fe fertilization. The only treatment that increased the number of fruits per tree, aril juice content and juice total soluble solids and decreased juice total acidity in both seasons was 2.6 mM FeSO₄. Both FeSO₄ doses caused consistent increases in the maturity index and total sugars in juice, along with minor decreases in juice total phenolic compounds. The antioxidant activity in juice was slightly decreased by 2.6 mM FeSO₄. In conclusion, early season foliar Fe fertilization had positive effects on pomegranate yield and quality, with FeSO₄ being better than Fe(III)-EDDHA. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

18 pages, 3544 KiB

Open AccessArticle

Grain Endogenous Selenium and Moderate Salt Stress Work as Synergic Elicitors in the Enrichment of Bioactive Compounds in Maize Sprouts

by Paolo Benincasa, Roberto D’Amato, Beatrice Falcinelli, Elisabetta Troni, Maria Chiara Fontanella, Sarah Frusciante, Marcello Guiducci, Gian Maria Beone, Daniela Businelli and Gianfranco Diretto

Agronomy 2020, 10(5), 735; https://doi.org/10.3390/agronomy10050735 - 20 May 2020

Cited by 21 | Viewed by 3465

Abstract

Salt stress and selenium are known to elicitate the production of plant secondary metabolites with antioxidant properties. On this basis, maize grains obtained from mother plants fertilized or not fertilized with selenium were sprouted at different levels of salinity (0, 25, and 50 [...] Read more.

Salt stress and selenium are known to elicitate the production of plant secondary metabolites with antioxidant properties. On this basis, maize grains obtained from mother plants fertilized or not fertilized with selenium were sprouted at different levels of salinity (0, 25, and 50 mM NaCl) to evaluate the effects on the sprout yield, inorganic and organic Se species, minerals, and secondary metabolites, as revealed by a metabolomics analysis. Grain endogenous selenium (135 mg kg⁻¹ vs. 0.19 mg kg⁻¹ of the non-enriched grain) and salinity affected the sprout yield and composition, with salinity having the greatest effect on secondary metabolites. Most of the Se in sprouts was in an inorganic form, despite Se-enriched grains only containing organic Se. Some synergic effect was observed between Se and salinity. The best combination was obtained with Se-enriched grains sprouted at 25 mM NaCl, since this provided a good yield (not lower than in the untreated control), while sprout shoots were enriched in selenocystine and pro-nutritional semipolar compounds with antioxidant properties. Therefore, using grains from Se-fertilized crops and sprouting them under mild salt stress might represent a promising technique for improving the nutritional value of sprouts. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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“Beyond the Source of Bioenergy”: Microalgae in Modern Agriculture as a Biostimulant, Biofertilizer, and Anti-Abiotic Stress

by Adewale Suraj Bello, Imen Saadaoui and Radhouane Ben-Hamadou

Agronomy 2021, 11(8), 1610; https://doi.org/10.3390/agronomy11081610 - 13 Aug 2021

Cited by 30 | Viewed by 6243

Abstract

Microalgae are photoautotrophic organisms with high commercial potential. Extracts from microalgae are extensively used in crop cultivation, mainly because they possess growth-promoting properties, coupled with their enhancing impacts on the crop’s ability to withstand abiotic stresses viz. extreme temperatures, drought, salinity, and mineral [...] Read more.

Microalgae are photoautotrophic organisms with high commercial potential. Extracts from microalgae are extensively used in crop cultivation, mainly because they possess growth-promoting properties, coupled with their enhancing impacts on the crop’s ability to withstand abiotic stresses viz. extreme temperatures, drought, salinity, and mineral deficiency. The chemical composition of microalgae extract includes carbohydrates, proteins, lipids, vitamins, micronutrients, macronutrients, and phytohormones (auxins, cytokinins, ethylene, abscisic acid, and gibberellins). This review aims to provide an update on the trending facts for a better understanding of growing microalgae, the production of biomass, the processing of microalgae extracts, summarizing bioactive compounds, and the chemical constituent of microalgae extracts. Furthermore, we review the supporting literature on the application of microalgae extracts as biostimulants and biofertilizers to enhance crop productivity and control abiotic stresses in crop cultivation. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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24 pages, 1186 KiB

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Biostimulant-Treated Seedlings under Sustainable Agriculture: A Global Perspective Facing Climate Change

by Anurag Malik, Virender S. Mor, Jayanti Tokas, Himani Punia, Shweta Malik, Kamla Malik, Sonali Sangwan, Saurabh Tomar, Pradeep Singh, Nirmal Singh, Himangini, Vikram, Nidhi, Gagandeep Singh, Vikram, Vinit Kumar, Sandhya and Aman Karwasra

Agronomy 2021, 11(1), 14; https://doi.org/10.3390/agronomy11010014 - 23 Dec 2020

Cited by 103 | Viewed by 13907

Abstract

The primary objectives of modern agriculture includes the environmental sustainability, low production costs, improved plants’ resilience to various biotic and abiotic stresses, and high sowing seed value. Delayed and inconsistent field emergence poses a significant threat in the production of agri-crop, especially during [...] Read more.

The primary objectives of modern agriculture includes the environmental sustainability, low production costs, improved plants’ resilience to various biotic and abiotic stresses, and high sowing seed value. Delayed and inconsistent field emergence poses a significant threat in the production of agri-crop, especially during drought and adverse weather conditions. To open new routes of nutrients’ acquisition and revolutionizing the adapted solutions, stewardship plans will be needed to address these questions. One approach is the identification of plant based bioactive molecules capable of altering plant metabolism pathways which may enhance plant performance in a brief period of time and in a cost-effective manner. A biostimulant is a plant material, microorganism, or any other organic compound that not only improves the nutritional aspects, vitality, general health but also enhances the seed quality performance. They may be effectively utilized in both horticultural and cereal crops. The biologically active substances in biostimulant biopreparations are protein hydrolysates (PHs), seaweed extracts, fulvic acids, humic acids, nitrogenous compounds, beneficial bacterial, and fungal agents. In this review, the state of the art and future prospects for biostimulant seedlings are reported and discussed. Biostimulants have been gaining interest as they stimulate crop physiology and biochemistry such as the ratio of leaf photosynthetic pigments (carotenoids and chlorophyll), enhanced antioxidant potential, tremendous root growth, improved nutrient use efficiency (NUE), and reduced fertilizers consumption. Thus, all these properties make the biostimulants fit for internal market operations. Furthermore, a special consideration has been given to the application of biostimulants in intensive agricultural systems that minimize the fertilizers’ usage without affecting quality and yield along with the limits imposed by European Union (EU) regulations. Full article

(This article belongs to the Special Issue Biostimulants and Micronutrients: Innovative Tools to Increase Crop Quality and Abiotic Stress Tolerance in Plants)

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