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Agronomic biofortification with selenium (Se) maybe employed to improve the nutritional value of food crops while increasing the plant’s tolerance to water deficit conditions. Although not essential for plants, Se may increase plant tolerance to water stress by boosting plants’ defence system activity. This study aimed to enrich common bean grains with Se and alleviate water deficit effects on common bean by applying Se to plants growing under greenhouse. Selenium was applied to soil at 0, 0.25, 0.5, 1.0, and 2.0 mg kg–1, under irrigated and water-deficit conditions. Antioxidant enzyme activities (SOD, CAT, and APX), H2O2 content, gas exchange, and SPAD index were assessed in plant leaves, and Se and nutrient concentrations were determined in grains. Results showed that water deficit decreased photosynthetic rate, stomatal conductance, transpiration rate, and increased water use efficiency. Selenium did not influence SPAD index in leaves from pod formation to maturity stage but improved the plant defence system by decreasing H2O2 content. Increasing Se rates increased Se concentration in grains and leaves. At lower Se rates, mainly at 0.25 mg Se kg–1, under water deficit, the activities of SOD, CAT, and APX reached their maximum values, and H2O2 content was minimum without reducing biomass production and nutrients accumulation. The highest Se rate (2 mg kg–1) was detrimental, since it decreased biomass production and the plant defence system under water deficit. Conclusively, soil Se addition enriched common bean plants with Se and showed positive responses against water deficit when applied at lower rates.

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The use of growth rings dimensional parameters has been an important tool for the understanding of growth, biomass allocation and climatic characterisation of forest species. However, its potential is unknown in perennial crops of socio‐economic importance, such as coffee. This work aimed to understand how the analysis of the growth rings can be used as a proxy to understand the climatic determinants of vegetative growth and biomass allocation in the different organs of coffee trees. The work was carried out in the southern region of Minas Gerais, Brazil. The structure of the growth rings of cross sections of the orthotropic stem of coffee trees (Coffea arabica L. cv. Arara) were analysed from 2011 to 2018, using standard dendrochronological techniques. Each year in that period was characterised climatically and by its bienniality. Pearson correlation statistical analysis was used for mapping the relation among annual radial growth rates of the trees and other assessed parameters as primary growth data, accumulated biomass and the climatic characteristics of the region on an annual and intra‐annual scale. During the study the water balance (conditioned by its components, Prec and ETo) and the maximum temperature were the main determinants of the characteristics of the formed ring and the plant biomass allocation. These growing characteristics were also influenced by the phenology that modulates the vegetative/reproductive growth cycles and in turn the biennial production cycles. The results show the potential of tree rings and dendrochronology as a tool that allows indirect, but long‐term, assessment of biomass allocation and growth in coffee trees.

Fall armyworm (FAW) Spodoptera frugiperda is considered the main defoliating insect pest of maize in many countries. Silicon (Si) applied to plants has been shown to increase the resistance to insects, especially in grasses such as maize. This study characterized the effects of Si fertilization regarding priming, induced resistance, and tolerance to FAW in a landrace variety and hybrid of maize. Si was applied in soil of potted-plants as H 4 SiO 4 at 2 t ha − 1 when maize plants were at V2 stage, and when they reached V3 two FAW neonates were infested in the plants whorls. Plants at V4 were reinfested with a 4thinstar larva that was kept feeding until V5 stage. Concentrations of H 2 O 2 and malondialdehyde were used as proxies of injury and oxidative stress, and activities of antioxidant enzymes were related to Si-induced responses on plants growth, and FAW injury and performance. As main results, there was reduced FAW injury and larval weight gain in Si-treated plants subjected to herbivory. Greater root dry mass was observed in the landrace variety with Si and without herbivory. Landrace plants showed higher shoot weights than the hybrid under FAW infestation. Si-fertilized plants showed higher H 2 O 2 concentrations.The highest peroxidase activities occurred in Si-treated plants without herbivory, and the catalase and superoxide dismutase activities were highest in Si-treated plants without herbivory or herbivory-injured plants without Si. These results are important for characterizing the Si-induced defense effects in maize to FAW, which can bene t the strategic use of Si in integrated pest management. Key MessageSpodoptera frugiperda is a polyphagous pest that threatens food security in many countries.Plants of maize landrace and hybrid were fertilized with Si to characterize triggered defense responses regarding induced resistance, priming, and tolerance to insect herbivory.Si effects on insect performance, plant growth, and antioxidant enzyme activities were more speci c to maize landrace and varied in conditions with and without herbivory.Si primed chemical defenses in landrace maize that were potentiated by induction of resistance following insect herbivory.

final maturation stages. In general, physiological differences between maturation stages were observed and can largely explain the different detachment forces required at different stages. In conclusion, there is no clear abscission zone between the peduncle and the coffee fruit cv."Icatu amarelo". Nevertheless, the decrease in the detachment force throughout the maturation process can occur due to the activity of cell wall-degrading enzymes together with increased oxidative stress during the fruit ripening.

Peach trees initiate flowering and then dense budding when the temperatures in winter are steadily low. When temperatures during the winter are high or when the chilling accumulation needs of the cultivar are not met, it is necessary to apply chemicals that stimulate flowering and budding in a uniform manner. This study aimed to evaluate alternative products for breaking the dormancy of ‘Kampai’ peach trees in a subtropical region. The experiment was conducted with ‘Kampai’ peach trees in the 2018, 2019 and 2020 production with the following treatments: (1) negative control composed only of water (control); (2) positive control composed of hydrogen cyanamide at a dose of 1.5% (commercial product Dormex®) plus 4.5% mineral oil; (3) Erger G® organomineral fertilizer supplemented with calcium nitrate at a dose of 3%; (4) potassium nitrate at a dose of 5%; and (5) copper sulphate at a dose of 0.3%. We evaluated affected budding capacity, flowering, the production cycle, peach production, the quality of peach trees and the enzymatic activities of catalase and guaiacol peroxidase. Hydrogen cyanamide and the organomineral fertilizer Erger G® promoted earlier flowering and an earlier production cycle. On the other hand, hydrogen cyanamide and copper sulphate stimulated flower opening and peach production. The chemicals used decreased catalase activity (24 h after application) and increased guaiacol peroxidase activity (6 h after application). The application of copper sulphate may be an option to break the dormancy of peach trees in the subtropics.

Fall armyworm (FAW) Spodoptera frugiperda is considered the main defoliating insect pest of maize in many countries. Silicon (Si) applied to plants has been shown to increase the resistance to insects, especially in grasses such as maize. This study characterized the effects of Si fertilization regarding priming, induced resistance, and tolerance to FAW in a landrace variety and hybrid of maize. Si was applied in soil of potted-plants as H4SiO4 at 2 t ha− 1 when maize plants were at V2 stage, and when they reached V3 two FAW neonates were infested in the plants whorls. Plants at V4 were reinfested with a 4th-instar larva that was kept feeding until V5 stage. Concentrations of H2O2 and malondialdehyde were used as proxies of injury and oxidative stress, and activities of antioxidant enzymes were related to Si-induced responses on plants growth, and FAW injury and performance. As main results, there was reduced FAW injury and larval weight gain in Si-treated plants subjected to herbivory. Greater root dry mass was observed in the landrace variety with Si and without herbivory. Landrace plants showed higher shoot weights than the hybrid under FAW infestation. Si-fertilized plants showed higher H2O2 concentrations. The highest peroxidase activities occurred in Si-treated plants without herbivory, and the catalase and superoxide dismutase activities were highest in Si-treated plants without herbivory or herbivory-injured plants without Si. These results are important for characterizing the Si-induced defense effects in maize to FAW, which can benefit the strategic use of Si in integrated pest management.