RESUMO
Most commercial apple orchards are established on either Marubakaido (Malus prunifolia Borkh.) (high vigor), M-9 (Malus pumila) (low vigor), or a combination of both rootstocks through the intergrafting technique. The Geneva® Series rootstocks were developed as an alternative to orchards modernization. The vigor of rootstocks influences the anatomical xylem formation and, therefore, the canopy cultivar's hydraulic conductivity. When affected by embolism, hydraulic conductivity harms plant metabolism, reducing crop yield and fruit quality. This study aimed to evaluate four Geneva® Series rootstocks with potential use in southern Brazil, in terms of hydraulic conductivity (K) and percentage loss of conductance (PLC), during the winter period in two different years. The G.213 rootstock presented the best performance for the variables analyzed; however, higher values of xylem functionality loss were observed in G.814.
Assuntos
Malus , Vazão de ÁguaRESUMO
The peach tree (Prunus persica) has a considerable global economic impact because its fruits are consumed worldwide. As climacteric fruits, peaches ripen after harvest and are also highly perishable postharvest. The aim of this study was to investigate alternatives for extending storage time and preventing a decline in quality in peaches using conventional cold storage (CS) compared with controlled atmosphere (CA) and ultralow oxygen (ULO) systems. A completely randomized design was used, with a 3 x 6 factorial scheme (3 storage systems x 6 storage times), thirteen parameters assessed by analysis of variances and significance by Tukey's test and regression. Total soluble solids (TSS) varied from 12.72 to 16.07ºBrix, titratable acidity (TA) declined during storage and pH varied significantly among the systems used from 40 days of storage onwards. The best TSS/TA ratio was obtained under ULO after 40 days, while firmness and weight loss declined in CA and ULO, contrasting with the brightly colored pulp. Reducing and non-reducing sugars decreased under CA and ULO at 30 and 40 days of storage, whereas phenolic compounds and antioxidant activity remained similar in these systems at 30, 40 and 50 days. Carotenoids remained stable for up to 40 days in ULO.CA and ULO maintained the best physical and chemical quality parameters, both systems being the most recommended. The phytochemical compounds analyzed in this study changed little during storage in the systems analyzed.(AU)
O pessegueiro (Prunus persica) apresenta grande impacto econômico global, por produzirem frutos apreciados em todo o mundo. Seus frutos climatérios amadurecem após a colheita, além disso, possuem alta perecibilidade pós-colheita. O objetivo deste trabalho foi buscar alternativas que ampliem ainda mais o tempo de armazenamento evitando-se o decaimento da qualidade dos pêssegos, utilizando o sistema refrigerado convencional (SAR) em contraponto com a atmosfera controlada (SAC) e dinâmica com ultrabaixo oxigênio (SAUO). O delineamento experimental foi inteiramente casualizado em um esquema fatorial 3 x 6 (3 sistemas x 6 períodos) de armazenamento, e treze parâmetros analisados pelo teste análise de variância, significância pelo teste Tukey e regressão. Os valores de sólidos solúveis variaram de 12,72ºBrix a 16,07ºBrix, a acidez titulável reduziu ao longo do armazenamento, já o pH apresentou variação significativa a partir de 40 dias entre os sistemas utilizados. A relação SS/AT alcançou os melhores índices no SAUO até 40 dias, já a firmeza de polpa e a perda de massa apresentaram redução nos SAC e SAUO, contrastando com elevada coloração da polpa. Açúcares redutores e não redutores apresentaram redução no SAC e SAUO aos 30 e 40 dias de armazenamento, já para os compostos fenólicos e atividade antioxidante, nestes sistemas, com 30, 40 e 50 dias os valores mantiveram-se semelhantes. Os carotenóides foram mantidos até 40 dias no SAUO. O SAC manteve os melhores parâmetros de qualidade físico-químicos analisados, juntamente com SAUO, sendo ambos os mais indicados. Os compostos fitoquímicos analisados neste estudo apresentaram poucas alterações durante os dias de armazenamento nos sistemas analisados.(AU)
Assuntos
Oxigênio , Produtos Agrícolas , Prunus persica , AntioxidantesRESUMO
The effects of ethylene on plants have been recognized since the Nineteenth Century and it is widely known as the phytohormone responsible for fruit ripening and for its involvement in a number of plant growth and development processes. Elucidating the mechanisms involved in the ripening of climacteric fruit and the role that ethylene plays in this process have been central to fruit production and the improvement of fruit quality. The biochemistry, genetics and physiology of ripening has been extensively studied in economically important fruit crops and a considerable amount of information is available which ranges from the ethylene biosynthesis pathway to the mechanisms of perception, signaling and control of gene expression. However, there is still much to be discovered about these processes and the objective of this review is to present a brief historic account of how ethylene became the focus of fruit ripening research as well as the development and the state-of- art of these studies at both biochemical and genetic levels.