Efeito da fertilização potássica e magnesiana em parâmetros de qualidade da cereja (Prunus avium L.) de Resende
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2020-01-10
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A cerejeira (Prunus avium L.) tem um elevado interesse económico, quer pelo
uso da sua madeira, quer pelo uso do seu fruto, a cereja. Esta pode ser consumida em
fresco ou usada no fabrico de compotas, sumos, iogurtes, entre outros. Esta espécie é
nativa da Europa, Anatólia, norte de África e oeste da Ásia. Em Portugal, a cerejeira
está distribuída a Norte do rio Tejo, mais predominantemente nas regiões da Beira
Interior e de Trás-os-Montes. A cereja tem inúmeros efeitos benéficos para a saúde,
devido às suas propriedades nutricionais, relacionado em parte com a presença de
compostos fenólicos, com características antioxidantes, cujos teores estão dependentes
de fatores climáticos e práticas agronómicas, como a fertilização. Assim, o presente
trabalho tem como objetivo avaliar o efeito da fertilização potássica (K) e magnesiana
(Mg) na qualidade da cereja da cultivar Burlat. Para tal, foi instalado um ensaio experimental num pomar de cerejeiras com sete anos de idade, localizado em Resende,
distrito de Viseu. Os tratamentos foram distribuídos por blocos, com dois níveis de aplicação foliar para cada um dos nutrientes estudados, K e Mg, num total de 4 modalidades. Para os nutrientes em estudo foram realizadas duas aplicações, relativas a duas concentrações, na forma do produto comercial ENERMAX, nas doses de 50 g hL-1 (T1) e 100 g hL-1 (T2), e KITPLANT Mg, nas doses de 125 g hL-1 (T3) e 250 g hL-1 (T4), para K e Mg, respetivamente. Para cada dose foram consideradas trêsrepetições, com 5 árvores por repetição, num total de 15 árvores por tratamento ou dose. Um tratamento controlo (T0) foi, também, considerado e no qual foram incluídas, igualmente, três repetições com 5 árvores por repetição. Neste último tratamento, aocontrário do procedimento normal, foram aplicados todos os nutrientes na forma dos produtos usando, para o efeito, a dose máxima de referência indicada pelo fabricante.vNas folhas, os resultados evidenciaram efeitos significativos nos teores de macro Ev icronutrientes. Para os macronutrientes, os maiores efeitos foram observados no casoBdo Ca, com a fertilização magnesiana a promover valores mais elevados deste elemento que a adubação potássica. No caso dos micronutrientes, os efeitos mais notados foram observados para o Zn e Mn, com a aplicação de Mg e K a promover uma diminuição e aumento dos respetivos teores. No fruto, foram analisados os seguintes parâmetros: peso, calibre, cor, firmeza, sólidos solúveis totais, pH, acidez titulável, perfil e composição fenólica e a sua atividade antioxidante. Os resultados obtidos demostram que as cerejas tratadas com K apresentaram frutos mais pesados, de maior calibre e com área das células da hipoderme e do parênquima de reserva de maiores dimensões, com implicação positiva na firmeza do fruto. O teor em sólidos solúveis totais aumentou em cerejas com aplicação de K e Mg. A aplicação de KITPLANT Mgem dose baixa promoveu um aumento da cor e teor de polifenóis, facto que se refletiu numa atividade antioxidante mais elevada e, consequentemente, num aumento da qualidade e benefícios nutricionais.
The cherry tree (Prunus avium L.) has a huge valuable economic interest, due to its wood and fruit usage, the cherry. This can be consumed on fresh or used in the manufacture of jams, juices, yogurts, among others. This species is native from Europe, Anatolia, North Africa and West Asia. In Portugal, the cherry tree is distributed by the North of the Tejo River, most predominantly in the regions of Beira Interior and Trás-os-Montes. Cherry has amount of beneficial health effects, due to its nutritional properties, related to the presence of phenolic compounds with antioxidant characteristics, witch dependents on climatic factors and agronomic practices such as fertilization. So the current study has as its main goal to go thought the effect of potassium (K) and magnesium (Mg) fertilization on the quality of Burlat cherry. For that, an experimental trial was installed in a seven-year-old cherry orchard located in Resende, Viseu district. The treatments were distributed in blocks, with two levels of foliar application for each of the studied nutrients, K and Mg, in a total of 4 modalities. For the nutrients under study, two applications were made, concerning two concentrations, in the form of the commercial product ENERMAX®, at the doses of 50 g hL-1 (T1) and 100 g hL-1 (T2), and KITPLANT Mg®, at doses of 125 g hL-1 (T3) and 250 g hL-1 (T4), for K and Mg, respectively. For each one, three replicates were considered, with 5 trees per repetition, in a total of 15 trees per treatment or dose. A control treatment (T0) was considered as well, it was repeated 3 times with 5 trees per repetition. In the last case, unlike the normal procedure, all nutrients were applied in the form of products, using for the effect, the maximum reference dose indicated by the manufacturer. In the leaves, the results showed significant effects on the macro and micronutrient contents. For macronutrients, the greatest effects were observed in the case of Ca, with Mg fertilization promoting higher values of this element than potassium fertilization. In the case of micronutrients, the most noticeable effects were observed for Zn and Mn, with the application of Mg and K promoting a decrease and increase of their contents. In fruit, were analysed some parameters: weight, size, colour, firmness, total soluble solids, pH, titratable acidity, profile and phenolic composition and its antioxidant activity. The results show that the cherries treated with K presented heavier fruits, larger size and higher area of hypodermis and storage parenchyma, with positive implication in fruit firmness. The total soluble solids content increased in cherries with K and Mg application. The application of low dose of KITPLANT Mg® promoted an increase in colour and polyphenol content, which reflected in a higher antioxidant activity and, consequently, an increase in quality and nutritional benefits.
The cherry tree (Prunus avium L.) has a huge valuable economic interest, due to its wood and fruit usage, the cherry. This can be consumed on fresh or used in the manufacture of jams, juices, yogurts, among others. This species is native from Europe, Anatolia, North Africa and West Asia. In Portugal, the cherry tree is distributed by the North of the Tejo River, most predominantly in the regions of Beira Interior and Trás-os-Montes. Cherry has amount of beneficial health effects, due to its nutritional properties, related to the presence of phenolic compounds with antioxidant characteristics, witch dependents on climatic factors and agronomic practices such as fertilization. So the current study has as its main goal to go thought the effect of potassium (K) and magnesium (Mg) fertilization on the quality of Burlat cherry. For that, an experimental trial was installed in a seven-year-old cherry orchard located in Resende, Viseu district. The treatments were distributed in blocks, with two levels of foliar application for each of the studied nutrients, K and Mg, in a total of 4 modalities. For the nutrients under study, two applications were made, concerning two concentrations, in the form of the commercial product ENERMAX®, at the doses of 50 g hL-1 (T1) and 100 g hL-1 (T2), and KITPLANT Mg®, at doses of 125 g hL-1 (T3) and 250 g hL-1 (T4), for K and Mg, respectively. For each one, three replicates were considered, with 5 trees per repetition, in a total of 15 trees per treatment or dose. A control treatment (T0) was considered as well, it was repeated 3 times with 5 trees per repetition. In the last case, unlike the normal procedure, all nutrients were applied in the form of products, using for the effect, the maximum reference dose indicated by the manufacturer. In the leaves, the results showed significant effects on the macro and micronutrient contents. For macronutrients, the greatest effects were observed in the case of Ca, with Mg fertilization promoting higher values of this element than potassium fertilization. In the case of micronutrients, the most noticeable effects were observed for Zn and Mn, with the application of Mg and K promoting a decrease and increase of their contents. In fruit, were analysed some parameters: weight, size, colour, firmness, total soluble solids, pH, titratable acidity, profile and phenolic composition and its antioxidant activity. The results show that the cherries treated with K presented heavier fruits, larger size and higher area of hypodermis and storage parenchyma, with positive implication in fruit firmness. The total soluble solids content increased in cherries with K and Mg application. The application of low dose of KITPLANT Mg® promoted an increase in colour and polyphenol content, which reflected in a higher antioxidant activity and, consequently, an increase in quality and nutritional benefits.
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Dissertação de mestrado em Bioquímica
Palavras-chave
Prunus avium L. , atividade antioxidante