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Pruning is an essential practice that helps control branch growth, optimize fruit size, and enhance fruit tree productivity. This study focused on ‘Valencia’ orange trees, which had experienced a decline in productivity after being cultivated on reclaimed lands for several years. The aim was to explore the impact of pruning intensity on vegetation growth, fruit yield, productivity, and fruit quality in these orange trees. The study involved 35-year-old ‘Valencia’ orange trees, which were subjected to four different levels of pruning. The pruning treatments included: T1—no pruning (control group), T2—light pruning (removal of 25% of main branches), T3—moderate pruning (removal of 50% of main branches), and T4—heavy pruning (removal of 75% of main branches). Each season, these pruning measures were consistently carried out on 15 February. The results indicated that the severity of pruning directly influenced vegetative growth parameters, such as shoot length and leaf area. As the pruning intensity increased, so did the growth of the vegetation. However, the overall volume of the tree’s canopy decreased compared to the control group. These findings provide insights into the relationship between pruning practices and the growth and productivity of ‘Valencia’ orange trees. The highest fruit yields were observed when pruning was carried out at a severity level of 75%, followed by 50 and 25%. These pruning treatments had a positive impact on various aspects of fruit quality, including weight, size, firmness, juice content, TSS (°Brix), TSS/acid ratio, and vitamin C content. Additionally, pruning contributed to a greater fruit yield per tree and an overall increase in the yield percentage. In essence, the findings suggest that pruning performed at different severity levels in February effectively promotes vegetation growth and enhances the physical and chemical properties of ‘Valencia’ orange trees. Notably, it resulted in a nearly 20% rise in fruit yield compared to the control group.

Este estudo teve como objetivo avaliar a produção e composição de laranjas de cv. Pista árvores tardias submetido a adubação de manutenção de potássio. O experimento foi conduzido em um pomar de cv. Lane Late em Rosário do Sul (RS). As laranjeiras foram submetidos a suplementação com 0, 50 ou 100% da dose recomendada de K2O em cada safra de 2008/2009 a 2011/2012. A produção de frutos, diâmetro do fruto, espessura da casca, volume de suco e suco, folha e os níveis de K no solo foram avaliados nas safras 2008/2009, 2010/2011 e 2011/2012. parâmetros de composição da fruta foram avaliados nos 2010/2011 e 2011/2012 safras. A aplicação de doses crescentes de potássio para CV. Pista laranjeiras atrasado para três safras não teve efeito sobre a produção de frutos. No entanto, a suplementação do solo com o potássio aumentou os níveis de nutrientes totais nas folhas e suco.

Sweet orange [Citrus sinensis (L.) Osbeck] fruit is one of the main citrus fruits, Navel and Valencia group sweet orange being the most representative and recognizable species of this species. The aims of this study were to determine genetic relationships and diversity of 84 Navel and 36 Valencia groups of sweet orange using SSR (simple sequence repeat) molecular markers. Twenty-six SSR primers were tested on these accessions. Seven SSR primers produced thirteen polymorphic fragments, eight SSR primers produced monomorphic fragments, and eleven SSR primers produced no scorable fragments. Thirteen SSR primers produced a total of 29 fragments and 13 of them were polymorphic. The number of average polymorphic fragments per primer was 1.93. The mean polymorphism information content (PIC) and marker index (MI) are 0.16 and 11.74, respectively. The Dice’s similarity coefficient among Navel and Valencia group sweet oranges ranged from 0.42 to 1.00 and matrix correlation (r) was 0.79. In the cluster analysis, Navel group sweet oranges were indicated as a separate group from Valencia group sweet oranges. ‘Antalya (40)’ was most distinct accessions from the others.

Dentre os micronutrientes, o Zn e o Mn limitam a produção dos citros, no Brasil. A aplicação foliar tem sido a forma tradicional de fornecimento, contudo, a eficiência desta adubação depende de uma série de fatores, entre eles o tipo de fertilizante. Foram realizados dois experimentos em pomar com laranjeiras Pêra, enxertadas em limão cravo, com sete anos de idade, em Botucatu, SP. No primeiro experimento foram avaliadas três fontes de Mn via foliar: carbonato de manganês A, carbonato de manganês B e sulfato manganoso, em duas doses para cada fertilizante, correspondente a 250 e 500 g ha-1 de Mn, mais o controle, pulverizado somente com água. No segundo experimento foram testadas três fontes de Zn para aplicação foliar: óxido de zinco A, óxido de zinco B e sulfato de zinco, em duas doses para cada fertilizante, correspondente a 375 e 750 g ha-1 de Zn, mais o controle. As amostragens de folhas foram realizadas mensalmente, iniciando aos 30 dias após aplicação dos tratamentos. A aplicação foliar com carbonato de manganês B, na dose de 500 g ha-1 Mn, e com óxido de zinco B, na dose de 750 g ha-1, proporcionaram, respectivamente, níveis nutricionais adequados de Mn e Zn nas folhas de laranjeira. Na ausência de chuvas, os teores adequados de Mn e Zn no solo, não permitem suprir satisfatoriamente as laranjeiras Pêra enxertadas em limoeiro cravo.Among micronutrients, Zn and Mn limit the production of citrus in Brazil. Foliar application has been the traditional form of supply, however the efficiency of this type of fertilization depends on a number of factors, including the type of fertilizer used. Two experiments were conducted in an orchard of seven year old Pêra orange, grafted onto Rangpur lime, in Botucatu, São Paulo. In the first experiment three sources of Mn, applied via foliar application, were evaluated: manganese carbonate A, manganese carbonate B and manganese sulphate, at two rates per fertilizer, corresponding to 250 and and 500g ha-1 of Mn, plus a control sprayed with water only. In the second experiment three sources of Zn were tested for foliar application: zinc oxide A, zinc oxide B and zinc sulphate at two rates per fertilizer, corresponding to 375 and 750g ha-1 of Zn, plus the control. Samples of leaves were collected monthly, beginning 30 days after application of the treatments. The foliar application of manganese carbonate B at a rate of 500g ha-1 Mn, and zinc oxide B at a rate of 750g ha-1, each provided adequate nutritional levels of Mn and Zn in the leaves of the orange. With the absence of rain, the appropriate levels of Mn and Zn in the soil are not enough to supply the Pêra orange grafted onto Rangpur lime.