Five Rootstocks for "Emperor" Mandarin Under Subtropical Climate in Southern Brazil.

Rootstocks modulate several characteristics of citrus trees, including vegetative growth, fruit yield and quality, and resistance or tolerance to pests, diseases, soil drought, and salinity, among other factors. There is a shortage of scion and rootstock cultivars among the combinations planted in Brazil. "Ponkan" mandarin and "Murcott" tangor grafted on "Rangpur" lime comprise the majority of the commercial mandarin orchards in Brazil. This low genetic diversity of citrus orchards can favor pest and disease outbreaks. This study aimed to evaluate the agronomic performance, Huanglongbing (HLB) tolerance, and fruit quality of "Emperor" mandarin on five different rootstocks for nine cropping seasons under the subtropical soil-climate conditions of the North region of the state of Paraná, Brazil. The experimental design was a randomized block, with six replications, two trees per block, and five rootstocks, including "Rangpur" lime, "Cleopatra," and "Sunki" mandarins, "Swingle" citrumelo, and "Fepagro C-13" citrange. The evaluations included tree growth, yield performance, fruit quality, and HLB disease incidence. "Emperor" mandarin trees grafted on "Rangpur" lime and "Swingle" citrumelo had early fruiting and high yield efficiency. "Rangpur" lime also induced the lowest tree growth, but low fruit quality. Trees on "Swingle" citrumelo and "Fepagro C-13" citrange showed low scion and rootstock affinity and produced fruits with high total soluble solids (TSS), with a lower number of seeds for those from trees on "Fepagro C-13" citrange. "Cleopatra" and "Sunki" mandarins induced higher juice content, while fruits from trees on "Cleopatra" also had higher TSS/titratable acidity (TA) ratio. "Emperor" mandarin trees were susceptible to HLB regardless of the rootstocks. Overall, "Cleopatra" and "Sunki" mandarins, "Swingle" citrumelo, and "Fepagro C-13" are more suitable rootstocks for "Emperor" mandarin under Brazilian subtropical conditions than "Rangpur" lime.

Analysis of the phenolic composition and yield of 'BRS Vitoria' seedless table grape under different bunch densities using HPLC-DAD-ESI-MS/MS.

Grapes are considered to be a major source of phenolic compounds as compared with other fruits. To improve the quality of table grapes, some techniques like thinning can be used. In addition, grape cultivars with distinct characteristics are directly linked to its phenolic profile. This study aimed to identify and quantify the phenolic compound profile and yield of the hybrid 'BRS Vitoria' seedless table grape under different bunch densities, using a combination of solid-phase extraction (SPE) methodologies and analytical high-performance liquid chromatography-diode array detector with tandem mass spectrometry (HPLC-DAD-ESI-MS/MS). A trial was carried out in 2016, in a commercial vineyard at Marialva, state of Parana (South Brazil). Three weeks after anthesis, the following bunch densities were evaluated: 4.0, 4.5, 5.0, 5.5, and 6 bunches per m2 (corresponding to an estimation of 16, 18, 20, 22, and 24 tons ha-1). The randomized block design was used as a statistical model with each treatment was replicated four times, with one vine per plot. Different characteristics were evaluated at harvest, e.g., soluble solids content (SS), total acidity (TA), maturation index (MI = SS/TA), bunch and berry masses, yield, as well hydroxycinnamic acid derivative (HCAD), anthocyanin, flavonol, and flavan-3-ol contents by HPLC-DAD-ESI-MS/MS analysis. The evaluated bunch densities did not interfere with the physicochemical characteristics of the berries, such as SS and MI. Under the density of 6.0 bunches per m2, the highest yield of 25 tons ha-1 was reached. Under all bunch densities, the phenolic profile presented the same compounds, but at different concentrations. Under a density of 5.0 bunches per m2, the compounds belonging to the anthocyanin and flavonol families were present in high concentrations. In contrast, at the densities of 4.0 and 4.5 bunches per m2, there was a reduction in the flavan-3-ol content. With respect to stilbenes, only the trans-piceid and its cis- isomer were detected. However, their concentrations had no significant influence on the evaluated bunch densities.

Degree of moisture in seeds for the cryopreservation of orchids native to Brazil / Grau de umidade para criopreservação de sementes de orquídeas nativas do Brasil

ABSTRACT: The objective of this study was to determine the ideal moisture degree for the cryopreservation of Cattleya labiata Lindl. and Miltonia regnellii Rchb.f. orchid seeds. Orchid seeds were standardized in relation to the desired moisture degrees (4, 6, 8, 10, 12, and 15%) and were subjected to rapid freezing in liquid nitrogen (-196 °C) for 24 h; then, the seeds were defrosted and analyzed. For both orchid species, the seeds that were immersed in liquid nitrogen with 4% moisture content had the highest viability percentage, averaging 95% and 68% of viable seeds for C. labiata and M. regnellii, respectively. The seeds with 12% and 15% moisture content had no viable seeds. For the fresh mass of seedlings, there was no significant difference between moisture content treatments for either species.

RESUMO: O objetivo deste trabalho foi determinar o grau de umidade ideal para criopreservação das sementes das orquídeas Cattleya labiata Lindl. e Miltonia regnelli Rchb.f.. As sementes das orquídeas foram padronizadas em relação aos graus de umidade desejados (4, 6, 8, 10, 12 e 15%) e submetidas ao congelamento rápido em nitrogênio líquido (-196 ºC) durante 24 horas; em seguida, descongeladas e analisadas. O maior percentual de viabilidade, tanto para as sementes de C. labiata quanto para M. regnelli, ocorreu quando as sementes foram imersas em nitrogênio líquido com 4% de umidade, atingindo 95 e 68% de sementes viáveis, respectivamente, sendo que, as sementes com 12 e 15% de umidade não apresentaram sementes viáveis. Em relação à massa fresca de plântula, não houve diferença entre os tratamentos (grau de umidade)para as espécies avaliadas.

Substrates and irrigation levels for growing desert rose in pots / Substratos e níveis de irrigação no crescimento em vaso de rosa do deserto

ABSTRACT In the past decades, desert rose has become a very popular ornamental plant, especially among collectors, due to its exotic and sculptural forms. However, it has been grown on a commercial scale only recently, and little is known about how to best manage it as a container-grown plant, or even which potting medium (substrate) to recommend. Therefore, the aim of this study was to investigate the interactions between potting media and irrigation levels for growing desert rose as a potted ornamental plant. The experiment was conducted in a greenhouse using a 6 x 2 factorial arrangement with six replications, six potting media and two irrigation levels. The mixes were characterized by measuring their physical properties, specifically the density and water retention capacity (WRC), as well as chemical properties, such as the pH and electrical conductivity (EC). After 210 days, plant growth and plant water consumption were evaluated and measured. A lower dry density for the vermiculite mixes was observed in comparison to that for the sand mixes. However, WRC ranged from 428 to 528 mL L-1 among the mixes, values considered close to ideal. In general, plant growth exhibited higher increases in mixes consisting of coconut fiber + sand or vermiculite, regardless of the irrigation level. Mixes of vermiculite + coconut fiber and sand + coconut fiber can be used to grow desert rose in pots, as long as irrigation is used to maintain the moisture content of the potting medium (mix) between 60-70% and 80-90% of the WRC.

RESUMO Na última década a rosa do deserto ganhou destaque no mercado de flores, principalmente entre colecionadores, devido às suas formas exóticas e esculturais; porém, o cultivo da espécie em escala comercial é bastante recente e pouco se sabe acerca do manejo da cultura, inclusive no que diz respeito à recomendação de substratos. Assim, objetiva-se nesse trabalho estudar a interação entre substratos e níveis de irrigação no desenvolvimento de rosa do deserto em vaso. Conduziu-se o experimento em casa de vegetação em esquema fatorial 6 x 2, com seis repetições, adotando-se seis substratos e dois níveis de irrigação. As misturas foram caracterizadas mensurando-se suas propriedades físicas (densidade e capacidade de retenção de água - CRA) e químicas (pH e condutividade elétrica - CE). Aos 210 dias de cultivo avaliou-se o crescimento das plantas; além do consumo de água pela cultura. Para as misturas compostas por vermiculita verificou-se menor densidade seca em relação às compostas por areia; no entanto, a CRA variou de 428 a 528 mL L-1 entre as misturas, valores próximos aos considerados ideais. De modo geral, o crescimento das plantas teve maiores incrementos nas misturas compostas por fibra de coco mais areia ou vermiculita, independente do nível de irrigação. As misturas vermiculita + fibra de coco e areia + fibra de coco podem ser empregadas para o cultivo em vaso de rosa do deserto, quando se mantiver os níveis de irrigação entre 60-70% e 80-90% da CRA das misturas.

Berry-cluster thinning to reduce compactness of ‘Black Star’ table grapes / Despenca como método de raleio para reduzir a compacidade de cachos da uva de mesa ‘Black Star’

ABSTRACT: The berry-cluster thinning technique was evaluated at different phenological times to prevent bunch compactness of ‘Black Star’ table grape, a new somatic mutation of ‘Brasil’ grape. The trial was carried out during 2012 and 2013 seaons in a vineyard situated in Marialva, PR, Brazil. Vines were trained in an overhead trellis system and spaced at 3x4m. The randomized block design was used as a statistical model with five replications and five treatments. The following treatments were evaluated: control; brushing prior to anthesis; and berry-cluster thinning at different times, when berries were 3-6, 7-10, or 11-15mm in diameter. The prevalence of bunch compactness was evaluated considering the levels: loose, medium loose, and dense bunches. The main physico-chemical characteristics of grapes and yield were also appraised. The data obtained were submitted to ANOVA, and toTukey’s test at 5% was applied. So, thinning is a mandatory practice to avoid bunch compactness of ‘Black Star’ grapes. The technique has to be performed, preferably, by means of brushing prior to anthesis, and the failure to accomplish this practice at this time, berry-cluster thinning when berries are 11-15mm in diameter can be used.

RESUMO: O método de raleio de bagas em diferentes fases fenológicas reduz a compactação de cachos da uva fina de mesa ‘Black Star’, uma nova mutação da uva ‘Brasil’. As videiras foram conduzidas em latada em espaçamento 3x4m, e o experimento foi realizado nas safras 2012 e 2013. O delineamento experimental consistiu em blocos casualizados, com cinco repetições e cinco tratamentos: controle sem raleio; raleio com escova plástica realizado no pré-florescimento e; despenca quando as bagas apresentavam 3-6, 7-10 ou 11-15mm de diâmetro. A compacidade predominante dos cachos foi avaliada de acordo com a seguinte classificação: cachos soltos, medianamente soltos e compactos. As características físico-químicas dos cachos e a produtividade também foram avaliadas. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5%. Verificou-se que o raleio de bagas é uma prática obrigatória na uva ‘Black Star’ para diminuir a compacidade dos cachos. A operação deve ser realizada, preferencialmente, com a escova plástica no pré-florescimento, e na impossibilidade de executar ou finalizar essa prática nesta fase, pode-se empregar a despenca quando as bagas apresentarem 11-15mm de diâmetro.