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Fruit crops under soil conservational management might sequester carbon (C) in soils and mitigate greenhouse gases emissions. Using grape pomace residues as soil amendment holds promise for sustainable viticulture. However, its actual capability to increase soil organic carbon (SOC) and nitrogen (N) is unknown, especially in subtropical climates. This research aims to investigate whether grape pomace compost and vermicompost can increase SOC, total N (TN), and C and N stocks in subtropical vineyards. Two vineyards located in Veranópolis, in South Brazil, one cultivated with 'Isabella' and the other with 'Chardonnay' varieties, were annually amended with these residues for three years. We quantified SOC and TN in each condition in different soil layers, as well as C and N content in two different granulometric fractions: mineral-associated organic matter (MAOM) and particulate organic matter (POM). C and N stocks were also calculated. Despite potential benefits, neither treatment enhanced SOC, its fractions, or C stocks. In fact, vermicompost was rapidly mineralized and depleted SOC and its fractions in the 0.0 to 0.05 m layers of the 'Isabella' vineyard. Our findings indicate that the tested grape pomace residues were unable to promote C sequestration in subtropical vineyards after a three-year period. [ABSTRACT FROM AUTHOR]

Environmental extremes, such as drought and flooding, are becoming increasingly common, resulting in significant crop losses. The aim of the present study was to understand the molecular response induced by drought and waterlogging conditions, and to link these responses to the physiological adaptation of plants. For this purpose, leaf RNA expression was analyzed in potted kiwifruit plants by Illumina Next Generation Sequences. Stressed plants showed an impairment of all physiological parameters (leaf-gas exchange and stem-water potential) with a more evident effect in waterlogging condition than in drought condition. However, the impact on the transcriptome in waterlogged plants was less intense than in drought stress. Drought affected several metabolic pathways, among which "plant hormone signal transduction", "protein processing in endoplasmic reticulum", and "mitogen-activated protein kinase signaling pathway" were the most representative in terms of number of genes involved. The genes involved in the biosynthesis of phenylpropanoids were positively influenced by both drought and waterlogging. Finally, waterlogging stimulated secondary metabolisms by upregulating the genes responsible for the biosynthesis of terpenoids and flavonoids, such as stilbenoids. The obtained results show that the two contrasting stress conditions share several common physiological responses and molecular mechanisms. [ABSTRACT FROM AUTHOR]

Brown spot (Stemphylium vesicarium) is a fungal disease widespread in European pear industry. The high number of fungicide applications required to control the disease can promote strains with fungicide resistance. The aim of the present study was to assess the effectiveness of soil- applied water solution of calcium chloride in combination with rootstock to control the incidence of brown spot in Abbé Fétel pear. Soil salinity, stem water and osmotic potential, along with fruit fraction of calcium and defence-mechanism related-enzymes such as peroxidase, polyphenol oxidase, phenyl-alanine ammonia-lyase, and β-1,3-glucanase were investigate in tree grafted on Fox 11 (Pyrus communis L.) and Sydo®, a quince (Cydonia oblonga) rootstock. Both grafting combinations were fertigated or not with calcium chloride. Sydo® showed a positive effect in reducing brown spot severity on Abbé Fétel. Compared to Fox 11, fruits from trees grafted on Sydo® showed higher calcium concentrations, fraction of calcium pectate, fruit firmness, polyphenol oxidase, phenyl- alanine ammonia-lyase and β-1,3-glucanase levels. Fruit calcium concentration was positively correlated with disease fruit tolerance. However, soil calcium applications were ineffective in promoting fruit calcium partitioning. Calcium chloride applications decreased leaf osmotic and stem water potential in trees grafted onto Sydo®, but this wasn’t found in those grafted on Fox 11. In conclusion, Sydo® rootstock promoted Ca acquisition, osmotic adjustment at leaf and fruit level, fruit synthesis of defence-related enzymes that all together reduced brown spot severity in Abbé Fétel pear.

Doped calcite (Fe-EDDHSA/CaCO3) was experimentally produced. The hypothesis of the present experiment is that, when roots get in contact with Fe-EDDHSA/CaCO3, the extrusion of H+ decreases the pH and dissolves calcite with subsequent release of Fe that becomes available for roots. The aim of the experiment was to determine whether doped calcite might represent a slow-release Fe source for in-vitro grown kiwifruit plantlets. The root elongation media used in the experiment had pH 8.0 and differed from each other for Fe supply as follow: Control medium that contained complete Murashige and Skoog salt mixture, including FeSO4 and Na2EDTA; calcite medium enriched with Fe-EDDHSA/CaCO3 as the only Fe source; −Fe medium without Fe. The absence of FeSO4 in the medium caused a reduction of plantlet growth. The final pH was higher with calcite medium than in control and −Fe. The addition of Fe-EDDHSA/CaCO3 increased Fe shoot concentration when compared with the −Fe medium. The data of the present experiment show the potential Fe slow release ability of Fe-EDDHSA/CaCO3; however, further investigation on Fe containing fertilizers should be conducted on potted plants to validate our results.

We evaluated the effect of the time of nitrogen (N) application on N uptake efficiency (NUE), partitioning and remobilization in walnut trees of cv Chandler grafted on seedlings. In February 2007, thirty, 2-year-old, trees were planted in 40-L pots and divided in 3 groups of 10 each, according to the time of N application: April 21 (bud burst), May 25 (pistillate flower maturity), September 12 (late summer). Each tree was addressed with 1 g of N (dissolved in water) as ammonium nitrate in which both ammonium and nitrate N were 15N enriched (5% atm.). One week after fertilization, 5 trees for each set were harvested and divided in: current growing shoots, leaves, stem and roots. All organs were dried, weighed milled and analyzed for 15N. At the end of the season the other 5 trees, for each set, were removed from the soil and two trees each group were harvested as above, while the other 3 trees were planted in fresh, 15N-uncontaminated soil until harvest (May 2008), when trees were divided into roots, stem, twigs, shoots, leaves and developing fruits. One week after fertilization the percentage of N derived from fertilizer (NDFF) was higher in trees fertilized in late summer followed by pistillate flower maturity and bud burst. At the end of the trial, the percentage of NDFF and NUE were unaffected by time of fertilization; shoot, leaves and developing fruits presented a higher percentage of NDFF than stem and roots, with no difference induced by timing of N application.

Nitrogen (N) is often applied to soil surface during the grapevine cycle, increases N losses. One way to reduce N losses lies on its application method, however how N dose and application mode impact on grapevines remain poorly investigated. The aim of this study is to evaluate the root growth, as well as grape must yield and composition, in a sandy soil and subjected to different N application doses and modes under subtropical climate conditions. Grapevines were implanted in 2011 and, since 2014, they were subjected to surface (N-Surf), and fertigation (N-Fert) N application, at rates of 0, 40 and 100 kg N ha−1 year−1. Leaf N concentration, yield, must quality parameters and root system morphology were evaluated in the 2016/2017 and 2017/2018 seasons. The application of N in both rates (40 and 100 kg N ha−1 year−1), in the N-Surf and N-Fert methods, increased the surface area of root, number of living roots and root production. The application of N rates, in both N application modes, provided adequate N supply to the soil and increased root system development, which contributed to the increase of soil N uptake by plants, higher N concentration in leaves and greater grape yield. However, N supply decreased the quality of the must, as observed in decreased TSS and total anthocyanins values and in increased total titratable acidity values, which are not desirable for red wine making processes. [ABSTRACT FROM AUTHOR]

Soil application of fresh organic matter is a way to increase soil organic matter and provide nutrients to trees. The effect of application of organic matter depends on the interaction among soil, root and microbial biomass. The aim of this research was to evaluate the potential release of N for hybrid GF677 (P. persica x P. dulcis) uptake, of 6 neemcakes available on the Italian market compared with fresh leaves of Melia azedarach, an ornamental tree that grows in the area of investigation. The release of N, and consequently root uptake was related to C:N ratio, the lower the ratio the higher the N concentration in plant tissues and plant growth. Using the 15N isotope technique, we found that up to 30% of the N applied with fresh Melia leaves, was accumulated in the tree, however the mineral N concentration in soil and plant and plant growth was not affected by the application of plant derivatives. [ABSTRACT FROM AUTHOR]

The decline of soil fertility due to intensification of agricultural practice can lead to reduced plant performances; the use of organic amendments could be a valuable strategy to overcome this this problem. The aim of the present study was to verify that the application of organic fertilizers may promote root growth to the detriment of the canopy by evaluating the effects of application of organic fertilizer on CO2 fixation, C partitioning, and plant growth. The experiment was carried out on strawberry (Fragaria × ananassa) plants, potted in 10 L pots. The following treatments were compared, in a complete randomized block design: (1) unfertilized control; (2) mineral fertilization; (3) cow manure (20 g kg−1 soil); (4) compost low rate (20 g kg−1 soil); (5) compost high rate (60 g kg−1 soil). Two months after their application, fertilizers did not affect plant growth; however, the application of compost at the high rate stimulated the 13CO2 assimilation. In the following 2 weeks, plants treated with compost at 60 g kg−1 soil showed a higher amount of 13C than the other treatments; however, the 13C relative partitioning was not affected by fertilization. Root:canopy ratio was decreased by mineral and compost high rate fertilizations, in response to the increase of root N concentration, indicating that root growth was stimulated by low soil N. [ABSTRACT FROM AUTHOR]

Abstract Background Asthma is a serious global health problem and its prevalence is increasing, especially among children. It represents a significant social and economic burden, and it can severely affect the health-related quality of life (HRQL) of patients. Among the numerous questionnaires aiming at evaluating asthma HRQL in children, the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) has proved to have good measurement properties. The present study was aimed at investigating the possible role of the Italian, self-administered version of the PAQLQ in the routine clinical evaluation of children affected by bronchial asthma. Methods 52 Italian children and adolescents (40 males and 12 females), aged 6 to 17 years, affected by allergic asthma, were enrolled. Each patient was evaluated twice, and at each visit asthma control and severity were assessed, spirometry was performed and the patients completed the self-administered version of the PAQLQ. Results The questionnaire was well-accepted and understood by the children. Children showed an overall good quality of life, with mild impairment in the activity and emotional function domains. The PAQLQ showed an overall good correlation with the clinical and functional indexes that are normally evaluated in follow-up visits of asthmatic patients. The PAQLQ appeared to be strongly related to asthma control, both at the first (p < 0.01) and second (p < 0.001) time of the study. The PAQLQ was also seen to decrease with increasing asthma severity. The results suggest a better compliance of the children towards completion of the questionnaire at t1. Finally, the PAQLQ does not appear to discriminate HRQL in patients with good lung function. Conclusion The Italian version of the PAQLQ is a quick-to-administer aid to clinical activity and can add valuable information to symptom reports, objective measurements and clinical assessment of asthma control and severity in daily clinical practice. Re-administration at each follow-up visit allows HRQL to be monitored over time.