EFEITO DA APLICAÇÃO DE CAULINO E ACIDO SALICILICO NA MITIGAÇÃO DO STRESS ESTIUAL EM OLIVEIRA

Funder

Organizational Unit

Publications

Application of anti-hail net in apple orchards: effects on fruits chemical characteristics

Publication . Martins-Gomes, Carlos; Pinto, Luís; Silva, Ermelinda; Martins, Sandra; Gonçalves, Alexandre; Brito, Cátia; Moutinho-Pereira, José; Rodrigues, M.A.; Correia, Carlos M.; Nunes, Fernando M.

Apple production in Portugal, over the last 15 years, has been subjected to increasing crop damage due to hailstorms and related meteorological extreme conditions. This problem has led farmers and researchers to find practical solutions to protect the orchards, such is the case of netting devices. The application of anti-hail nets in apple tree orchards looks to provide protection against the roughest meteorological events (such as hail, strong winds, and sunburn), while avoiding to upset the development of the plant and or, if possible, helping to improve the plant’s productivity. During 2016, this work was carried out in Carrazeda de Ansiães, a northeast Portuguese plateau zone that is a primary location for apple production, and the application of a grey anti-hail net, which reduces photosynthetically active radiation by 12 %, was tested in an orchard with the cultivars Golden delicious and Fuji of apple tree (Malus domestica Borkh). Control without screen net applied was also used. In order to understand the effects of the net, apples were collected and analysed for their chemical characteristics (total phenols, ortho-diphenols and flavonoids content, ABTS and polyphenolic profile). The obtained results in apple peel revealed, in both cultivars, a decrease in total phenols, ortho-diphenols and flavonoids concentration, whereas in the Fuji cultivar the antioxidant activity, determined by the ABTS assay, was maintained. Pulp results showed little difference with lower (P<0.001) ortho-diphenols content in Fuji cultivar and slightly lower (P<0.05) ABTS activity in Golden delicious cultivar. Peel and pulp methanolic extracts were analysed by HPLC-DAD. The phenolic profile was similar for both cultivars, with the exception of anthocyanins, being identified chlorogenic acid and derivatives of quercetin. The antihail net did not affect the phenolic profile, only decreased the polyphenols concentration. The use of a grey anti-hail net on apple orchards is a suitable alternative for the protection of apple trees against hail ensuring the production of the crop without compromising fruit quality.

2017Conference object

Open access

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

Publication . Brito, Cátia; Dinis, Lia Tânia; Silva, Ermelinda; Gonçalves, Alexandre; Pavia, Ivo; Arrobas, Margarida; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.

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.

2017Conference object

Open access

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

Publication . Brito, Cátia; Dinis, Lia Tânia; Silva, Ermelinda; Gonçalves, Alexandre; Meijón, Mónica; Escandón, Mónica; Arrobas, Margarida; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.

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.

2019Journal article

Open access

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

Publication . Brito, Cátia; Dinis, Lia Tânia; Silva, Ermelinda; Gonçalves, Alexandre; Rodrigues, M.A.; Moutinho-Pereira, José; Barros, Ana I.R.N.A.; Correia, Carlos M.

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.

2018Conference object

Open access

Efeito da aplicação de glicina e betaína na atividade fotossintética da oliveira em regime de sequeiro

Publication . Martins, Sandra; Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Rocha, Luís; Pinto, Luís; Pavia, Ivo; Ferreira, Helena; Dinis, Lia Tânia; Luzio, Ana; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.

A oliveira [Olea europaea L.) é uma espécie que frequentemente se encontra sujeita a longos períodos de seca e altas temperaturas, o que afeta a sua atividade fisiológica e, consequentemente, a sua produtividade. A glicina betaína é um importante soluto orgânico que apresenta um papel crucial na tolerância das plantas a alguns tipos de stresse/ incluindo o défice hídrico, por estar envolvido em processos como ajustamento osmótico, destoxificação de espécies reativas de oxigénio e proteção de macromoléculas, sendo também reserva de carbono e fonte de azoto. O objetivo do presente estudo foi investigar os efeitos da aplicação foliar de glicina betaína (25 mM) na atividade fotossintética de oliveiras (cv. Cobrançosa) em plena produção, cultivadas em regime de sequeiro na Terra Quente Transmontana (Suçães, Mirandela). A aplicação do bioestimulante foi efetuada no início do verão e a atividade fisiológica, centrada nas trocas gasosas e no estado hídrico, foi avaliada ao longo dos 3 meses seguintes. A aplicação de glicina betaína conduziu, em julho, a um aumento da taxa de fotossíntese e da eficiência intrínseca do uso da água durante o período da manha, e da condutância estomática durante a tarde. Por outro lado, as plantas tratadas com bioestimulante apresentaram aumento do conteúdo relativo em água no mês de agosto. Os resultados sugerem que a aplicação de glicina betaína provocou um aumento da atividade fisiológica a curto prazo, verificando-se perda de efeito a o longo do tempo. Justifíca-se a necessidade de estudos futuros no sentido de otimizar a concentração e o número de aplicações deste metabolito para obter uma melhor performance da oliveira em condições de sequeiro.

2017Conference object

Open access