Use of kaolin as a summer stress alleviating product in olive orchards under rainfed conditions

In a changing world, where is expected the temperatures rising and the reduction in precipitation in some semi-arid areas of the globe, the search for new agronomic practices that help crops to maintain and/or increase yields and quality is a continuous challenge. Kaolin (KL) exogenous application has been considered a short-term solution to alleviate the adverse effects of summer stress. The formed particle film increases the reflection of excess radiation reducing the risk of leaf damage from heat load accumulation and solar injury. Olive trees (Olea europaea L.) cultivated under rainfed conditions were sprayed with KL (5%) during two consecutive years in the beginning of the summer season. In general, relatively to the control group, KL-sprayed plants showed an enhancement in leaf water status, stomatal conductance and photosynthetic capacity and a reduction in leaf sclerophylly. In the severest period analyzed, at the end of the second-year summer, KL has lost the effectiveness of keeping gas exchange above the control measurements. However, in both years, allowed a faster restauration of the physiological functions in early autumn and contributed to higher crop yield. Overall, the results of the present investigation revealed that KL were effective in preventing the adverse effects of summer stress on crop performance and yield.Doctoral fellowship under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/2012) provided by the FCT-Portuguese Foundation for Science and Technology to C. Brito (PD/BD/52543/2014). Institution CITAB, for its financial support through the European Investment Funds by FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Program, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013.info:eu-repo/semantics/publishedVersio

Weather year-to-year variations determine the influence of kaolin and salicylic acid in olive fruits and oil phenolic composition

Olive tree (Olea europaea L.) growing area is threatened by the current and predicted adverse environmental conditions, affecting negatively the quality of the olive products, largely known for its benefits in human diet. Thus, agronomic strategies may be implemented to offset those negative effects. During two consecutive years young olive trees under rainfed conditions were sprayed in the beginning of the summer season with 100 M salicylic acid (SA), a stress signaling phytohormone, or with kaolin 5% (KL), a heat and irradiance reflecting clay. The distinct weather conditions during the fruit development stage, with higher rainfall close to the harvest and the early frost events, in the first year, and the warmer and drier summer, in the second year, contributed to the increase in phenolic compounds in fruits and in olive oil from the first to the second year. Both KL and SA increased crop yield, while, in general, phenolics concentrations of both olives and oil were increased and decreased by the applied products in the first and second year, respectively. This dissimilar response was modulated by the distinct weather conditions, demonstrating the effectiveness of the applied products in attenuating the frost-promoted degradation of phenolic compounds in the first year and in mitigating the extreme adverse conditions felt in the summer of the second year. The phenolic composition was also distinctly affected, since total phenols, ortho-diphenols and flavonoids exhibited different trends. It is hard to conclude a specific influence of the applied products on olives and oil phenolic composition, since the weather year-to-year variations determine different plant responses.Doctoral fellowship under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/2012) provided by the FCT-Portuguese Foundation for Science and Technology to C. Brito (PD/BD/ 52543/2014). Institution CITAB, for its financial support through the European Investment Funds by FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Program, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013.info:eu-repo/semantics/publishedVersio

Cicatrização da ferida operatória de cirurgia cardíaca com cianocrilato

Objective: to follow the healing of a sternotomy surgical wound in which cyanoacrylate bandaging was used, in children who underwent heart surgery. Methods: prospective cross-sectional study performed with children during the immediate postoperative period of heart surgery, with the average of 12 and both genders. The data collected were performed using an instrument. The variables were: bleeding, hyperemia, hematoma, ecchymosis, secretion from surgical wound and extracorporeal circulation time. Results: eighty-six patients were included, with median of 17 (7 - 65) months, 43 (50%) male. The most prevalent surgery was interventricular communication 31(36%). The length of stay in the intensive care unit was 8.7 ± 9.7 days. The showed that in 67 (77%) of the patients the surgical wound healed well. Conclusion: the cyanoacrylate bandage during the post-surgery period immediately after pediatric heart surgery achieved adequate surgical healing, with lower risk of infection due to less handling of the surgical woundObjetivo: percibir la evolución de la herida operatoria por estereotomía con curativo de cianocrilato, en niños sometidos a cirugía cardiaca. Métodos: estudio transversal prospectivo, con niños en postoperatorio inmediato, de ambos sexos, con edad < 12 años. La recolecta de datos se realizó mediante un instrumento. Las variables fueron: sangramiento, hiperemia, hematoma, equimosis, secreción y tiempo de circulación extracorpórea. Resultados: fueron incluidos 86 pacientes, con edad mediana de 17 (7-65) meses, 43 el (50%) del sexo masculino. La cirugía más prevalente fue comunicación interventricular 31 el (36%). El tiempo de internación en la unidad de terapia intensiva fue 8,7 + 9,7 días. Los resultados comprueban que 67 el (77%) de los pacientes presentaron buena evolución de la herida operatoria. Conclusión: el curativo con cianocrilato en el postoperatorio inmediato de cirugía cardiaca pediátrica contribuye para una adecuada cicatrización quirúrgica, con reducción de riesgos de infecciones, pues hay una disminución en la manipulación de la herida operatoria.Objetivo: Verificar a evolução da ferida operatória por esternotomia realizada com curativo de cianocrilato, em crianças submetidas à cirurgia cardíaca. Métodos: estudo transversal prospectivo, realizado com crianças no pós-operatório imediato, de ambos os sexos, com idade ≤ 12 anos. A coleta de dados foi realizada através de um instrumento. As variáveis foram: sangramento, hiperemia, hematoma, equimose, secreção na ferida operatória e tempo de circulação extracorpórea. Resultados: Foram incluídos 86 pacientes, com mediana de idade de 17 (7 - 65) meses, 43 (50%) do sexo masculino. A cirurgia mais prevalente foi comunicação interventricular 31 (36%). O tempo de internação na unidade de terapia intensiva foi 8,7 ± 9,7 dias. Os resultados demonstraram que 67 (77%) dos pacientes apresentaram boa evolução da ferida operatória. Conclusão: O curativo com cianocrilato no pós-operatório imediato de cirurgia cardíaca pediátrica contribuiu para uma adequada cicatrização cirúrgica, com redução de riscos de infecções devido a uma menor manipulação da ferida operatória

Salicylic acid improves the tolerance of olive trees against the Mediterranean adverse summer conditions

The projected climate changes in the Mediterranean region, that include low rainfall, excessive heat load and high daily irradiance, are of utmost relevance for rainfed olive orchards, since are expected negative consequences on physiology, growth, productivity and quality. In this sense, agronomic strategies may be implemented to offset those negative effects. Rainfed young olive trees (Olea europaea L.) cv. Cobrançosa were sprayed with 100 M salicylic acid (SA), a signaling phytohormone with diverse regulatory roles in abiotic stresses responses. The results demonstrate that SA influenced positively the leaf water status, stomatal conductance and photosynthetic capacity of rainfed trees. The protective action of SA is associated with the induction of some stress tolerance indicators, as the increase in soluble proteins and ascorbate concentrations, and the improvement of plant nutritional status. This more comfortable conditions during the summer period allowed a faster restauration of the physiological functions in the early autumn. Finally, the sprayed plants exhibited higher yields than the control ones. In summary, SA seems to be an efficient strategy to improve olive tree tolerance against the adverse summer conditions of Mediterranean region.Doctoral fellowship under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/2012) provided by the FCT-Portuguese Foundation for Science and Technology to C. Brito (PD/BD/52543/2014). Institution CITAB, for its financial support through the European Investment Funds by FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Program, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013.info:eu-repo/semantics/publishedVersio

Kaolin and salicylic acid foliar application modulate yield, quality and phytochemical composition of olive pulp and oil from rainfed trees

Olive orchards, rainfed managed, are threatened by the current and predicted adverse environmental conditions, which change the yield and quality of olive products, largely known for its benefits to human health. To mitigate these problems, it is highly recommended to perform some adjustments in agronomic practices, such as the use of foliar sprays that cloud help the trees to cope with climate change. During two consecutive years, olive trees were pre-harvest sprayed with kaolin (KL) and salicylic acid (SA) to attenuate the adverse effects of summer stress. Olive yield was increased by 97% and 72% with KL and SA, respectively. Phenolics and antioxidant capacity of both olives and olive oil increased and decreased in the first and second year, respectively, in a closely association with the prevailing climatic conditions. The foliar sprays did not significantly affect the oil quality indices, free acidity, peroxide value and K232 coefficient and decreased the K270 coefficient. This study strongly suggests that the applied products might be effective in mitigating the adverse environmental conditions, without substantial changes in fruit and olive oil quality.Doctoral fellowship under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/2012) provided by the FCT-Portuguese Foundation for Science and Technology to C. Brito (PD/BD/ 52543/2014). Institution CITAB, for its financial support through the European Investment Funds by FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Program, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013. INTERACT project - "Integrative Research in Environment, Agro-Chains and Technology", no. NORTE-01-0145- FEDER-000017, in its lines of research entitled ISAC, co-financied by the European Regional Development Fund (ERDF) through NORTE 2020 (North Regional Operational Program 2014/2020).info:eu-repo/semantics/publishedVersio

Kaolin and salicylic acid alleviate summer stress in rainfed olive orchards by modulation of distinct physiological and biochemical responses

In a changing world, the search for new agronomic practices that help crops to maintain and/or increase yields and quality is a continuous challenge. We aim to evaluate kaolin (KL) and salicylic acid (SA) effectiveness as summer stress alleviating agents through physiological, biochemical and immunohistochemical analysis. Olive trees (Olea europaea L. cv. Cobrançosa) grown under rainfed conditions were sprayed with 5% KL and 100 μM SA, at the beginning of summer, during two consecutive years. KL enhanced relative water content (RWC), stomatal conductance (gs) net photosynthesis (A) and leaf indole-3-acetic acid (IAA) signal, and decreased leaf sclerophylly, secondary metabolites and non-structural carbohydrates accumulation and abscisic acid (ABA).The trees treated with SA showed changes on IAA and ABA dynamics, and an enhancement in RWC, gs, A, soluble proteins, and leaf P and Mg concentrations during the summer. Notably, KL and SA also allowed a faster restauration of the physiological functions during stress relief. In sum, KL and SA foliar sprays alleviated the negative effects induced by summer stress in olive trees performance, by modulation of distinct physiological and biochemical responses.info:eu-repo/semantics/publishedVersio

Kaolin spray induces changes in ABA and IAA immunodistribution in olive leaves.

The climate change scenarios predicted the accentuation of drought and high temperature events during the summer season in the Mediterranean region, coming up harmful consequences to important crops of this region, such as olive tree (Olea europaea L.). Stress conditions often stimulate changes in plants production, distribution or signal transduction of phytohormones as a response, then modifying their physiology and biochemistry. Kaolin (KL) is a reflecting clay that applied on leaves surface reduce the common damages promoted by heat load and high irradiance levels, being important to test its effect on olive tree hormonal dynamics and physiological parameters. Olive trees of a rainfed orchard in Northeast Portugal, were sprayed with kaolin 5% (KL) and water (C). The immunodistribution of two hormones, abscisic acid (ABA) and indoleacetic acid (IAA), and some physiological and growth responses were accessed. The ABA signal was substantially more pronounced than the IAA signal in all the analyzed leaves, concomitant with the stressful conditions of which these plants were subjected. In general, ABA signal showed a uniform distribution throughout the leaf in both treatments. However, its intensity was higher in C than in KL-sprayed leaves, reflecting the better water status and higher stomatal conductance of the last plants. While in C leaves was observed a uniform distribution of IAA signal trough the leaf limb and an almost absence of signal in the main vascular tissues, in KL-sprayed leaves was observed a higher signal intensity in the main vascular tissues and upper palisade parenchyma. These data suggest its transport and an active growth in KL plants, concomitant with the higher increase of canopy volume. Thus, immunodetection appears to be an efficient tool to understand the translocation of IAA and ABA in plants treated with abiotic stress alleviating products and clarify their role in regulating the physiological responses.info:eu-repo/semantics/publishedVersio

Kaolin and salicylic acid alleviate summer stress effects on rainfed olive orchards through distinct physiological and biochemical processes

In a changing world, the search for new agronomic practices that help crops to maintain and/or increase yields and quality is a continuous challenge. Olive trees cultivated under rainfed conditions were sprayed with 5% kaolin (KL) and 100 μM salicylic acid (SA) during two consecutive years in the beginning of the summer season. Exogenous KL enhanced relative water content (RWC), stomatal conductance (gs) net photosynthesis (A) and IAA immunodetection, and decreased leaf sclerophylly, secondary metabolites and non-structural carbohydrates accumulation, ABA signal and DNA methylation, contributing to higher growth and yield. The plants treated with SA showed an enhancement in RWC, gs, A, soluble proteins, IAA, ABA and DNA methylation immunodetection and leaf P and Mg concentrations during the summer, leading to higher yield. Thus, KL and SA alleviated some of the negative effects induced by summer stress in olive tree performance, allowing a faster restauration of the physiological functions during the stress relief and leading to higher yieldsThis work was funded by the INTERACT project – “Integrative Research in Environment, Agro-Chains and Technology”, no. NORTE-01-0145-FEDER-000017, in its lines of research entitled ISAC, co-financed by the European Regional Development Fund (ERDF) through NORTE 2020 (North Regional Operational Program 2014/2020).info:eu-repo/semantics/publishedVersio

Use of kaolin as a reflective clay improves olive tree physiological and yield responses under different environmental conditions

Olive tree (Olea europaea L.) growing area is threatened by the current and predicted adverse environmental conditions, affecting negatively plant performance and yield. Thus, agronomic strategies to offset those negative effects and improve olive orchards sustainability need to be implemented. In this regard, we propose the use of kaolin particle film, a natural heat and irradiance reflecting clay. To achieve a more comprehensive response about kaolin (5%) action, during two consecutive years we performed two different experiments, in different geographical locations of Portugal north-west with “Cobrançosa” cultivar: established olive trees under conventional rainfed conditions and under deficit irrigation (27.5% of ETc). Generally, during the summer period, kaolin was effective in improving water status and photosynthetic response, by reducing both stomatal and non-stomatal limitations. Moreover, improved leaf gas exchange restauration after the first rains persists during the winter months in rainfed conditions. Kaolin also reduces leaf sclerophylly, inducing shade-related leaf characteristics. As a result of better physiological performance achieved with kaolin application, yield increased 97% and 54.6% in rainfed and deficit irrigation conditions, respectively. Overall, the results of the present investigation revealed a cost-effective strategy to attenuate the negative effects of summer stress in olive trees, while allows to save water. Ultimately, this practice might contribute to increase the sustainability and competitiveness of this sector and anticipate solutions to the negative effects of climate change.This work was funded by the INTERACT project – “Integrative Research in Environment, Agro-Chains and Technology”, no. NORTE-01-0145-FEDER-000017, in its line of research entitled ISAC, co-financed by the European Regional Development Fund (ERDF) through NORTE 2020 (North Regional Operational Program 2014/2020).info:eu-repo/semantics/publishedVersio

Olive tree physiology and chemical composition of fruits are modulated by different deficit irrigation strategies

To overcome constrains affecting olive groves, cropping practices focusing on agronomic water use efficiency and their impact on quality parameters must be investigated. We evaluated the response of olive trees (Olea europaea, cv. Cobrançosa) to different water regimes, full irrigation (FI, 100% ETc) and three deficit irrigation strategies (DIS) (regulated (RDI, irrigated with 80% of crop evapotranspiration (ETc) in phases I and III of fruit growth and 10% of ETc in the pit hardening stage) and two continuous sustained strategies (SDI), a conventional SDI (27.5% of ETc), and a lowfrequency irrigation adopted by the farmer (SDIAF, 21.2% of ETc). RESULTS The effects of water regimes on the plant water status, photosynthetic performance, metabolites fluctuations and fruit quality parameters were evaluated. All DIS treatments enhanced leaf tissue density, RDI and SDI generally did not affect leaf water status and maintained photosynthetic machinery working properly, while SDIAF treatment impaired olive tree physiological indicators. DIS treatments maintained the levels of primary metabolites in leaves, but SDIAF plants showed signs of oxidative stress. Moreover, DIS treatments led to changes in the secondary metabolism, both in leaves and in fruits, with increased total phenolic compounds, ortho-diphenols, and flavonoids concentrations, and higher total antioxidant capacity, as well higher oil content. Phenolic profiles showed the relevance of an early harvest in order to obtain higher oleuropein levels with associated higher health benefits. CONCLUSION Adequate DIS are essential for sustainable olive growing, as they enhance the competitiveness of the sector in terms of olive production and associated quality parameters.info:eu-repo/semantics/publishedVersio