ABSTRACT The aim of this study was to evaluate the effect of controlled atmosphere storage on quality of native and cultivated yerba mate produced in Arvorezinha (RS) and São Mateus do Sul (PR) after 0, 3, 6 and 12 months of storage under ambient conditions, low oxygen (1.0 kPa) and high carbon dioxide (3.0 kPa) partial pressures. Total chlorophyll concentration reduced over the storage period regardless of the atmosphere condition, form of cultivation and production region. Total carotenoids, regardless of the form and place of cultivation, decreased until three months of storage under 1.0 kPa O2. Although, the O2 reduction to 1.0 kPa maintains greener color and higher chlorophyll concentration after 12 months of storage. High carbon dioxide partial pressures (3.0 kPa) in the storage chamber increases the polyphenol concentration until six months of storage. The raw material originated from São Mateus do Sul (PR) has higher chlorophyll concentration and greener color, resulting in greater storage potential.

ABSTRACT The objective of this work was to evaluate the effects of low, ultra-low, and extremely low partial pressures of O2 in a controlled atmosphere (CA) and 1-methylcyclopropene (1-MCP) on the postharvest quality of ‘Cripps Pink’ apples. The treatments used were 21.00 kPa of O2 (cold storage [CS]), CS + 1-MCP, and CA conditions with 2.00, 1.00, 0.60 and 0.25 kPa of O2, without 1-MCP. All fruit were stored at 1.5 ± 0.2 °C, relative humidity (RH) 92 ± 2%, and partial pressure of CO2 < 0.5 kPa, for 4.5 and 8 months, followed by another seven days of shelf life (20 ± 2 °C/RH of 60 ± 5%). Respiration and ethylene production rates were reduced in all CA conditions and the CS + 1-MCP treatment when compared to the CS without 1-MCP, in both storage periods. The application of 1-MCP delayed ripening and reduced the quality loss of the fruits stored for 4.5 months. The CA with 0.6 and 0.25 kPa of O2 reduced the incidence of superficial scald, decay, mealiness, and skin greasiness, and maintained the background color of the epidermis of the fruits in storage for 8 months. Among the CA conditions, the treatment of 0.25 kPa presented the highest production of ethanol and acetaldehyde in the fruits stored for 8 months. Treatment of 0.6 kPa of O2 kept higher values of total phenolic compounds, in the peel and flesh, in both storage periods. Fruits stored under 0.6 kPa of O2 showed the best quality after 8 months of storage.

ABSTRACT The objective of this work was to evaluate the effect of extremely low-oxygen storage on the aerobic, anaerobic metabolism and overall quality maintenance of ‘Royal Gala’ and ‘Galaxy’ apples stored at two temperatures. For ‘Royal Gala’ apples, four treatments were evaluated in a two-factor scheme (2 × 2), with two storage conditions: [1] 1.2 kPa O2 + 2 kPa CO2; [2] 0.8 kPa O2 + 1.6 kPa CO2; and two temperatures (1.0 and 1.5 °C). For ‘Galaxy’ apples, the experiment was conducted in a two-factor (3 × 2) scheme with three storage conditions: [1] 1.2 kPa O2 + 2 kPa CO2; [2] 0.8 kPa O2 + 1.6 kPa CO2; [3] 0.4 kPa O2 + 1.2 kPa CO2, and two temperatures (1.0 and 1.5 °C). The ‘Royal Gala’ apples stored under 0.8 kPa O2 + 1.6 kPa CO2 at 1.5 °C had higher flesh firmness, healthy fruit and soluble solids along with lower incidence of flesh breakdown and mealiness. The ‘Galaxy’ apples stored under 0.4 kPa O2 + 1.2 kPa CO2, at temperature of 1.5 °C had lower 1-carboxylic acid-1-aminocyclopropane (ACC) oxidase enzyme activity, ethylene production, occurrence of mealiness, when compared to 1.0 °C. The storage of these two cultivars at 1.5 °C with extremely low O2 partial pressures is possible. The possibility to increase the storage temperature from 1 °C, which is traditionally used for these mutants, to 1.5 °C allows to keep better quality with the advantage of energy saving.

ABSTRACT The Gala cultivars represent about 65% of the Brazilian apple production, however, it has a short harvest period, making necessary to use technologies that anticipate or delay fruit maturation. A widely used technology is the preharvest application of growth regulators. The objective of this investigation was to evaluate the effect of preharvest application of naphthalene acetic acid (NAA) combined with aminoethoxyvinylglycine (AVG) and 2-chloroethylphosphonic acid (Ethephon), on the quality of ‘Brookfield’ apple at harvest and after eight months controlledatmosphere (CA)(1.2 kPa O2 and 2.0 kPa CO2) storage followed by seven days of shelf life at 20 °C. The treatments were: [1] Control: application of water only; [2] NAA (40 g.ha-1); [3] NAA (40 g·ha-1) plus Ethephon (2.0 L·ha-1 24% of active ingredient), and [4] NAA (40 g·ha-1) plus AVG (0.83 kg.ha-1 15% of active ingredient). At harvest, fruit treated with NAA presented a higher level of starch degradation, ethylene production and respiration rate. Fruit treated with NAA plus AVG maintained better quality after eight months under CA storage plus seven days of shelf life, due to higher healthy fruit amount and higher flesh firmness, but this combination reduced the red skin color index. Additionally, NAA plus Ethephon may be an alternative to maintain the quality of ‘Brookfield’ apple during storage in comparison to the application of NAA isolated.

ABSTRACT The aim of this study was to evaluate the effect of storing ‘Royal Gala’ apple under extremely low oxygen partial pressures on their anaerobic metabolism, ethylene production and fruit quality after 9 months of storage plus 7 days of shelf life at 20 °C. The storage conditions tested were: 1.2 kPa O2 + 2.0 kPa CO2; 0.7 kPa O2 + 1.5 kPa CO2; 0.5 kPa O2 + 1.2 kPa CO2; 0.4 kPa O2 +1.2 kPa CO2 and 0.25 kPa O2 + 0.0 kPa CO2. The fruit storage temperature was 1.0 °C (± 0.1). Fruit stored at 0.4 kPa O2 + 1.2 kPa CO2 maintained higher flesh firmness and a higher percentage of healthy fruit. The fruit stored under the 0.25 kPa O2 + 0.0 kPa CO2 condition had lower flesh firmness as well as a reduced percentage of healthy fruit and a high production of anaerobic metabolism compounds, such as ethanol and ethyl acetate, which may have caused fruit quality loss. The storage of ‘Royal Gala’ apple under 0.4 kPa O2 + 1.2 kPa CO2 is a technique that can be commercially applied to keep a better fruit quality after a 9 months storage period.

RESUMO A podridão parda do pessegueiro, causada pelo fungo Monilinia fructicola, é a principal doença da cultura, causando danos significativos tanto em pré-colheita como pós-colheita. O estudo objetivou avaliar a aplicação pré-colheita de fungicidas, no controle da podridão parda e verificar o papel da infecção latente e contaminação externa na incidência da doença em pós-colheita. Foi conduzido um experimento nos anos de 2014 e 2015 para avaliar o desempenho de seis ingredientes ativos em pré-colheita (captana, iprodiona, iminoctadina, tebuconazol, difenoconazol e azoxistrobina) no controle da podridão parda e o efeito sobre infecções latentes. Um segundo experimento objetivou monitorar a infecção latente durante o crescimento e maturação dos frutos, correlacionando-a com a incidência da doença em pós-colheita. Os dados formam submetidos a análise de variância (Anova) e as médias agrupadas pelo teste de Scott-Knott (p < 0,05) com o software estatístico Sisvar. Os produtos iprodione, tebuconazol e difenoconazol foram os mais eficientes no controle da podridão parda a campo, enquanto o iminoctadine possui maior eficiência em pós-colheita, agindo inclusive sobre as infecções latentes. A incidência de infecções latentes tanto na fase de crescimento quanto maturação tem correlação positiva com a podridão parda em pós-colheita. A maior incidência da doença após o armazenamento foi em decorrência da manifestação de infecções latentes. O eficiente controle químico no campo, durante toda a fase de crescimento e maturação dos frutos é uma importante estratégia para o controle pós-colheita, inclusive após o armazenamento refrigerado e durante a vida de prateleira sob 20 oC.

ABSTRACT The peach brown rot, caused by Monilinia fructicola, is the main disease of the crop, causing significant losses during preharvest and postharvest. This study aimed to evaluate the performance of preharvest fungicide application on brown rot control and verify the role of latent infection and external contamination in postharvest disease. An experiment was carried out in the years 2014 and 2015 in order to evaluate the performance of six active ingredients (captan, iprodione, iminoctadine, tebuconazole, difenoconazole and azoxystrobin) during preharvest on brown rot control and the effect on latent infection. A second experiment was carried out to monitor the latent infection during growth and ripening of the fruit and in order to correlate it with the postharvest disease incidence. The data were submitted to analysis of variance (Anova) and the means were grouped by the Scott-Knott test (p < 0.05), using statistical software Sisvar. The active ingredients iprodione, tebuconazole and difenoconazole were the most efficient in controlling brown rot on the field, while iminoctadine has higher efficiency during postharvest control, acting on latent infections. The incidence of latent infections during fruit growth and ripening has a positive correlation with brown rot incidence at postharvest. The highest disease incidence after storage is due to the latent infections manifestation. Effective chemical control in the field, throughout the growing and ripening of fruit, is an important approach to postharvest brown rot control, even after cold storage and during shelf life at 20 °C.

RESUMO Foram conduzidos dois experimentos com o objetivo de avaliar o efeito da atmosfera controlada (AC) associada ao 1-metilciclopropeno (1-MCP; 1,0 μL L-1), à indução de perda de massa (IPM; 2%) e ao baixo etileno (BE; <0,04 μL L-1 de C2H4) sobre a manutenção da qualidade de ameixas ‘Laetitia’. No experimento 1, em 2010, os tratamentos avaliados foram armazenamento refrigerado (AR; 21 kPa O2 + <0,03 kPa CO2), AC1 (1 kPa O2 + 1 kPa CO2), AC1+1-MCP, AC1+IPM e AC1+BE. No experimento 2, em 2011, os tratamentos foram AR, AC2 (2 kPa O2 + 2 kPa CO2), AC2+1-MCP e AC2+IPM. Em ambos os experimentos, os frutos foram armazenados a 0,5±0,1 ºC e 96±2% de umidade relativa. A AC retardou o amadurecimento, em ambas as atmosferas avaliadas, e reduziu o escurecimento de polpa de ameixas ‘Laetitia’, especialmente na AC2. O 1-MCP, o BE e a IPM apresentaram efeito adicional à AC1 na manutenção da consistência da polpa. O 1-MCP, independente da condição de AC, e a IPM, na condição de AC1, reduziram o escurecimento da polpa. A AC1, independente do uso de tecnologias complementares, reduziu a incidência de podridões e de rachaduras.

ABSTRACT Two experiments were conducted to evaluate the relative effects of controlled atmosphere (CA) associated with 1-methylcyclopropene (1-MCP; 1.0 μL L−1), induction of mass loss (IML; 2%), and low ethylene (LE; <0.04 μL L−1 of C2H4) on the quality preservation of ‘Laetitia’ plums. In experiment 1 (2010), the treatments evaluated were cold storage (CS; 21.0 kPa O2 + <0.03 kPa CO2), CA1 (1 kPa O2 + 1 kPa CO2), CA1 + 1-MCP, CA1 + IML, and CA1 + LE. In experiment 2 (2011), the treatments evaluated were CS, CA2 (2 kPa O2 + 2 kPa CO2), CA2 + IML, and CA2 + 1-MCP. In both experiments, the fruit were stored at 0.5 ± 0.1°C and 96 ± 2% RH. CA storage delayed fruit ripening in both atmosphere conditions evaluated and reduced the internal browning of the ‘Laetitia’ plums, particularly in CA2. 1-MCP, LE, and IML had additional effects to CA1 on preserving flesh consistency. 1-MCP, irrespective of the CA condition, and IML, in CA1, reduced internal browning. CA1, regardless of the complementary technologies, reduced the incidence of decay and fruit cracking.

RESUMO O armazenamento de peras ‘Rocha’ em atmosfera controlada (AC) mantém a qualidade dos frutos por períodos prolongados. Contudo, condições inadequadas de AC podem favorecer a perda da capacidade de amadurecimento e a ocorrência de escurecimento de polpa nos frutos. Este trabalho teve como objetivo avaliar os efeitos de AC com ultrabaixo O2 (UBO), e com baixo O2 (BO) associado a diferentes teores de CO2 sobre o amadurecimento e a ocorrência de escurecimento de polpa em peras Rocha. Os tratamentos avaliados foram: pO2 = 0,5 kPa (UBO) e pCO2 < 0,03 kPa; pO2 = 1,0 kPa (BO) e pCO2 < 0,03 kPa; pO2 = 1,0 kPa e pCO2 = 1,0 kPa; pO2 = 1,0 kPa e pCO2 = 2,0 kPa; e pO2 = 1,0 kPa e pCO2 = 3,0 kPa. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Os frutos foram colhidos em Vacaria, RS, e armazenados nas cinco diferentes condições de AC durante 270 dias (-0,5±0,1 ºC e umidade relativa de 96±2%). Os frutos foram avaliados após o armazenamento em AC em relação às taxas respiratória e de produção de etileno, cor da casca, firmeza de polpa, atributos de textura, acidez titulável (AT), teor de sólidos solúveis (SS), análise sensorial, incidência e severidade de escurecimento de polpa e cor da polpa. Os frutos armazenados em BO com pCO2 < 0,03 kPa apresentaram menor perda de firmeza de polpa, além de uma coloração da casca mais amarela. Não houve diferença entre as condições de armazenamento para a análise sensorial, teor de SS e AT. A condição de BO com pCO2 = 3,0 kPa apresentou maior incidência e severidade de escurecimento de polpa. As condições de pO2 = 0,5 kPa e pCO2 < 0,03 kPa) e pO2 = 1,0 kPa e pCO2 = 1,0 kPa são as mais indicadas para o armazenamento de peras ‘Rocha’.

ABSTRACT The storage of ‘Rocha’ pears under controlled atmosphere (CA) preserves fruit quality for long periods. However, inadequate CA conditions might impair ripening and lead to flesh browning. This research was carried out to assess the effects of CA with ultra-low (ULO), and low O2 (LO) associated with different CO2 levels on ripening and occurrence of flesh browning in ‘Rocha’ pears. Treatments evaluated were: pO2 = 0.5 kPa (ULO) and pCO2 < 0.03 kPa; pO2 = 1.0 kPa (LO) and pCO2 < 0.03 kPa; pO2 = 1.0 kPa and pCO2 = 1.0 kPa; pO2 = 1.0 kPa and pCO2 = 2.0 kPa; and pO2 = 1.0 kPa and pCO2 = 3.0 kPa. A completely randomized experimental design was used, with four replicates. Fruits were harvested in Vacaria, RS, and stored under five CA conditions during 270 days (-0.5±0.1 ºC and relative humidity of 96±2%). Fruits were assessed after CA storage for respiratory rate, ethylene production, skin color, flesh firmness, texture, titratable acidity (TA), soluble solids content (SSC), sensory attributes, flesh browning incidence and severity and flesh color. Fruits stored under LO with pCO2 < 0.03 kPa had higher flesh firmness and more yellow skin color than fruits stored under other CA conditions. Sensory attributes, SS and TA of fruits were not affected by CA conditions. Fruit stored under LO with pCO2 = 3.0 kPa had the highest incidence (48%) and severity of flesh browning. The pO2 = 0.5 kPa and pCO2 < 0.03 kPa and pO2 = 1.0 kPa and pCO2 = 1.0 kPa conditions are the most suitable for the CA storage of ‘Rocha’ pears.

RESUMO O objetivo do trabalho foi avaliar o efeito da aplicação de etanol e duas doses de óxido nítrico na manutenção da qualidade de maçãs ‘Galaxy’ durante o armazenamento em atmosfera controlada (AC). Tratamentos utilizados: [1] 1,2 kPa O2 + 2,0 kPa CO2; [2] AC + aplicação de 20 µL L-1 de óxido nítrico; [3] AC + aplicação de 40 µL L-1 de óxido nítrico; [4] AC + aplicação de 1 mL de etanol kg-1 de fruto. Os frutos foram mantidos em AC durante oito meses e sete dias a 20º C. Frutos tratados com etanol apresentaram maior produção de etileno, menor firmeza, elevada degenerescência, polpa farinácea e produção de acetaldeído. Já, os frutos tratados com 40 µL L-1 de óxido nítrico, apresentaram menor produção de etileno, taxa respiratória e atividade da enzima ACC (1-aminociclopropano-1-carboxílico) oxidase. Maçãs tradadas com 20 µL L-1 de óxido nítrico apresentaram aumento na produção de etileno e respiração, etileno e CO2 interno, e produzem mais etanol. A aplicação de etanol e óxido nítrico, não apresentam benefícios na manutenção da qualidade dos frutos após o armazenamento em AC devido a menor firmeza de polpa, maior ocorrência de polpa farinácea, degenerescência de polpa e incidência de podridões nos frutos.

ABSTRACT The aim of this work was to evaluate the effect of ethanol and two nitric oxide dose applications on the maintenance of the post-storage quality of ‘Galaxy’ apple during storage under controlled atmosphere (CA). Treatments evaluated were: [1] 1.2 kPa O2 + 2.0 kPa CO2; [2] CA + 20 µL L-1 of nitric oxide, [3] CA + 40 µL L-1 of nitric oxide; [4] CA + 1 ml of ethanol kg-1 fruit. Fruits received treatments before storage and were kept under CA during eight months and seven days of storage at 20 °C. Fruits had been kept on CA for eight months and seven days at 20° C. Fruits treated with ethanol showed higher ethylene production, low flesh firmness, high flesh breakdown, mealiness and acetaldehyde production. Fruits treated with 40 µL L-1 nitric oxide showed lower ethylene production, respiration rate and ACC oxidase ( (1-aminocyclopropane-1-carboxylic acid) oxidase enzyme activity. Apples treated with 20 uL L-1 nitric oxide showed higher ethylene production, respiration rate, internal ethylene concentration CO2 and ethanol concentration. Ethanol and nitric oxide application before storage have no benefits in maintaining fruit quality after storage under CA due to lower flesh firmness, higher mealiness incidence, flesh breakdown and decay incidence.

RESUMO O objetivo deste trabalho foi avaliar o efeito de condições de armazenamento em atmosfera controlada (AC) e da composição mineral do fruto sobre ocorrência de escurecimento da polpa em pera ‘Rocha’. Os frutos foram armazenados sob diferentes condições de AC: 0,5 kPa O2 + < 0,03 kPa CO2; 1,0 kPa O2 + < 0,03 kPa CO2; 1,0 kPa O2 + 1,0 kPa CO2; 1,0 kPa O2 + 2,0 kPa CO2 e 1,0 kPa O2 + 3,0 kPa C2. Os frutos foram avaliados quanto à incidência e severidade de escurecimento da polpa após 9 meses de armazenamento (−0,5 ± 0,1 °C e UR de 96 ± 2%). Posteriormente, frutos com e sem a presença do distúrbio foram avaliados quanto às concentrações de Ca, Mg, K, N e as relações K/Ca, Mg/Ca e N/Ca. O armazenamento sob 1,0 kPa O2 + 3,0 kPa CO2 proporcionou aos frutos maior incidência de escurecimento da polpa em relação aos armazenados sob 0,5 kPa O2 + < 0,03 kPa CO2 e 1,0 kPa O2 + < 0,03 kPa CO2, ocasionando ainda maior severidade do distúrbio em comparação às demais condições de armazenamento. Peras com escurecimento da polpa apresentaram menores concentrações de Ca, bem como concentrações mais elevadas de K e maiores relações dos elementos K/Ca, Mg/Ca e N/Ca, comparativamente a frutos sem incidência do dano. Todavia, a análise multivariada de todos esses elementos minerais mostrou que a relação K/Ca foi a mais indicada para discriminar frutos sem e com escurecimento da polpa em peras ‘Rocha’.

ABSTRACT The aim of this study was to evaluate the effect of controlled atmosphere (CA) conditions and mineral contents on flesh browning in ‘Rocha’ pear. The fruits were stored at different CA conditions: 0.5 kPa O2 + < 0.03 kPa CO2; 1.0 kPa O2 + < 0.03 kPa CO2; 1.0 kPa O2 + 1.0 kPa CO2; 1.0 kPa O2 + 2.0 kPa CO2 and 1.0 kPa O2 + 3.0 kPa CO2. Fruit were evaluated for incidence and severity of flesh browning after 9 months of storage (−0.5 ± 0.1 °C and 96 ± 2% RH). Also, fruit with and without the disorder were assessed for contents of Ca, Mg, K, and N, as well as the K/Ca, Mg/Ca, and N/Ca ratios. Fruit stored at 1.0 kPa O2 + 3.0 kPa CO2 had higher incidence of flesh browning than those stored at 0.5 kPa O2 + < 0.03 kPa CO2 and 1.0 kPa O2 + < 0.03 kPa CO2, as well as higher severity of disorder than all the other storage conditions. Pears with flesh browning had lower Ca content, as well as higher K content and higher K/Ca, Mg/Ca, and N/Ca ratios than fruit without the disorder. However, the multivariate analysis of all these mineral elements showed that the K/Ca ratio provides the best discrimination between fruit with and without flesh browning in ‘Rocha’ pears.

ABSTRACT Flesh browning is a physiological disorder that occurs in ‘Fuji’ apples during storage, which causes considerable postharvest losses of fruit produced in Southern Brazil. This work aimed to assess the mineral attributes [Ca; Mg and K contents and the Mg/Ca; K/Ca and (K + Mg)/Ca ratios] associated with the flesh browning disorder incidence, as well as to identify which of these mineral attributes better discriminate the differences in the degree of susceptibility to flesh browning disorder in ‘Fuji’ apples stored under controlled atmosphere (CA; 1.2 kPa O2 + 2.0 kPa CO2 and 1.2 kPa O2 + < 0.5 kPa CO2; 0.5 ± 0.1 °C and 96 ± 2% RH, during an 8-month period). Apples from 2 orchards in Fraiburgo, Santa Catarina, 3 orchards in São Joaquim, Santa Catarina, and 3 orchards in Vacaria, Rio Grande do Sul were used. The fruit with flesh browning disorder has lower levels of Ca and a higher Mg/Ca ratio when compared to the fruit without flesh browning. The Mg and K contents were not related to the physiological disorder. The canonical discriminant analysis (CDA) showed that the isolated Ca content better discriminated the fruit with and without flesh browning disorder. ‘Fuji’ apples with Ca contents < 80 mg∙kg−1 in the flesh present a greater risk of developing this disorder in the Southern Brazil production region.

RESUMO: O objetivo deste trabalho foi avaliar a interação entre estádios de maturação e temperatura de armazenamento na qualidade de frutos de amora-preta ‘Guarani’ armazenados em atmosfera controlada (AC). O experimento foi conduzido em esquema fatorial (2x2), avaliando-se dois estádios de maturação (E1: cor vermelha e E2: cor preta dos frutos) e duas temperaturas (1°C e 5°C). Os frutos foram armazenados em AC (10.0kPa O2+15.0Pa CO2) e 98±1% de umidade relativa. Os resultados mostraram que o componente principal 1 (PC I) e o componente principal 2 (PC II) responderam por 92,84% de variação das variáveis analisadas. Conclui-se que a colheita não deve ser realizada em estádio de maturação antecipado, pois a amora-preta ‘Guarani’ não desenvolve todas as características de qualidade para o consumidor. A amora-preta ‘Guarani’ deve ser armazenada na temperatura de 1°C. Os estádios de maturação apresentam maior importância na variação dos parâmetros de qualidade quando comparados a temperaturas de armazenamento.

ABSTRACT: The aim of this research was to evaluate the interaction between maturity stages and temperature on fruit quality of ‘Guarani’ blackberries stored under controlled atmosphere (CA). The experiment was conducted in a factorial scheme (2x2), evaluating two ripening stages (E1: red-color and E2: black-color of fruits) and two temperatures (1°C and 5°C). The fruit were stored in CA (10.0kPa O2+15.0kPa CO2) and 98±1% of relative humidity (RH). Results showed that the principal component 1 (PC I) and principal component 2 (PC II) corresponded to 92.84% of the overall variation of the evaluated variables. Harvest should not be performed in the early maturity stage, because ‘Guarani’ blackberries do not develop all quality of consumer. ‘Guarani’ blackberries must be stored at 1°C. The maturity stage showed the major importance in the overall variability of quality parameters when compared to storage temperature.

RESUMO: O impacto da adubação nitrogenada na produção e composição de frutos em pomares de laranjeiras cultivados em solos com baixo ou médio teor de matéria orgânica do RS é pouco conhecido. Este trabalho objetivou avaliar como a adubação nitrogenada, em solo de textura arenosa, pode interferir na produção, composição de frutos e do suco em laranjeiras cv. 'Lane Late'. O experimento foi conduzido em um pomar de laranjeiras cv. 'Lane Late' instalado sobre um Argissolo Vermelho, em Rosário do Sul (RS). As plantas foram submetidas à aplicação de 0, 20, 40, 60, 80, 100, 120, 140 e 160 kg ha-1 de N. Nas safras de 2010/2011 e 2011/2012 foi avaliado o teor total de N em folhas, o número de frutos por planta, a produção, o peso fresco e diâmetro de frutos, espessura da casca, porcentagem de suco nos frutos, cor da epiderme e do suco, os valores de vitamina C, sólidos solúveis totais (SST) e acidez total titulável. Na primeira safra, especialmente a produção, o número de frutos por planta, o teor de SST no suco e o ratio diminuíram com o aumento da dose de N aplicada. Mas, na segunda safra, de forma destacada, o teor de acidez total titulável no suco aumentou com a dose de N aplicada. Nas duas safras, os resultados foram muito influenciados pela distribuição das precipitações pluviométricas, que afetam a fisiologia da planta, a dinâmica do N no solo e, por consequência, a probabilidade de resposta ao N aplicado, bem como as perdas de N mineral no solo.

ABSTRACT: Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv. 'Lane Late' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late' growing in Sandy Typic Hapludalf soil, in Rosário do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil.

RESUMO Trabalhos recentes têm demonstrado que a atmosfera modificada (AM) passiva retarda o amadurecimento de ameixas ‘Laetitia’, mas causa maior ocorrência de escurecimento da polpa do que o armazenamento refrigerado (AR), possivelmente devido ao acúmulo de CO2 e/ou ao etileno no interior da embalagem. O objetivo deste trabalho foi avaliar o efeito da AM ativa, com absorção de CO2, combinada com baixo etileno (BE) sobre o amadurecimento e a manutenção da qualidade de ameixas ‘Laetitia’ durante o armazenamento a 0,5ºC±0,1ºC e UR de 96%±2%. Os tratamentos avaliados foram: AR (21 kPa de O2 + 0,03 kPa de CO2); AM + absorvedor de CO2; AM + absorvedor de CO2 e BE; AM com perfuração (duas perfurações de 0,5 mm de diâmetro) + absorvedor de CO2; AM com perfuração + absorvedor de CO2 e BE. Nos tratamentos com AM, foi utilizado o filme de polietileno de baixa densidade de 40 µm. As pressões parciais médias de O2 + CO2 (kPa) foram 2,8 + <0,1 e 1,2 + <0,1, em AM com perfuração e AM sem perfuração, respectivamente. A AM ativa, especialmente em embalagem não perfurada, com absorvedor de CO2 e BE (<0,04 µL L-1), retardou o amadurecimento dos frutos, mas não reduziu a incidência de escurecimento da polpa após 60 dias de armazenamento. Os frutos acondicionados em AM ativa, em embalagem com ou sem perfuração, com absorvedor de CO2 e BE, apresentaram menor intensidade de escurecimento da polpa do que em AR.

ABSTRACT Recent studies have shown that passive modified atmosphere storage (MA) delays the ripening of ‘Laetitia’ plums but it increases the incidence of internal browning in comparison to cold storage (CS), possibly due to high CO2 and/or ethylene accumulation inside the package. The aim of this study was to evaluate the effect of active MA conditions [LDPE film (40 µm)] with CO2 absorber combined with low ethylene (LE) on ripening and quality preservation of ‘Laetitia’ plums during storage at 0.5ºC±0.1ºC and RH of 96%±2%. The treatments evaluated were cold storage (CS; 21.0 kPa O2 + <0.03 kPa CO2); nonperforated MA with CO2 absorber; non-perforated MA with CO2 absorber and LE; perforated MA (with two perforations with diameter = 0.5 mm) with CO2 absorber; and perforated MA with CO2 absorber and LE. The partial pressures of O2 + CO2 (kPa) were 1.2 + <0.1 and 2.8 + <0.1, in non-perforated and perforated MA, respectively. Active MA, mainly non-perforated package, with CO2 absorber and LE, delayed fruit ripening, but did not reduce the incidence of internal breakdown in ‘Laetitia’ plums cold stored for 60 days. Fruits in active MA, with perforated or non-perforated package, with CO2 absorber and LE, showed lower intensity of internal breakdown than CS.

RESUMO: Neste trabalho avaliamos se o uso de 1-metilciclopropeno (1-MCP), associado com diferentes tempos de resfriamento entre a colheita e o armazenamento, substitui o pré-resfriamento em maçãs ‘Galaxy’. Os tratamentos foram arranjados em esquema fatorial, combinando os fatores aplicação de 1-MCP (com ou sem) e diferentes tempos entre a colheita e o resfriamento (24h, 96h, 144h e 192h, em 2013; e 24h, 48h, 144h e 240h, em 2014). Após quatro meses de armazenamento refrigerado (1,0±0,2°C/92±5% de UR), foram avaliados: firmeza de polpa, textura, acidez titulável (AT), sólidos solúveis (SS) e cor da epiderme. As maçãs tratadas com 1-MCP apresentaram maior firmeza de polpa, textura e SS, em ambos os anos, e maior AT e menor incidência de polpa farinácea em comparação a maçãs não tratadas com 1-MCP, em 2013. O 1-MCP foi eficaz em manter a qualidade dos frutos, mesmo com o retardo do resfriamento em até 240h. O retardo do resfriamento de 192h e 240h em maçãs ‘Galaxy’ não tratadas com 1-MCP deve ser evitado, pois diminui a qualidade dos frutos.

ABSTRACT: In this research it was evaluated if the use of 1-methylcyclopropene (1-MCP), associated to different cooling times between the harvest and storage, replaces the pre-cooling in ‘Galaxy’ apples. Treatments were arranged in a factorial scheme, combining the following factors: application of 1-MCP (with or without) and different times between harvest and cooling (24 hours, 96 hours, 144 hours and 192 hours in 2013; and 24 hours, 48 hours, 144 hours and 240 hours in 2014). After four months of cold storage (1.0±0.2°C/92±5% RH - Relative Humidity) were evaluated: flesh firmness, texture, titratable acidity (TA), soluble solids (SS) and skin color. Apples treated with 1-MCP showed greater flesh firmness, texture and SS, in both years, and more TA and lower incidence of mealy flesh compared to apples not treated with 1-MCP in 2013. The 1-MCP was effective in maintaining the fruit quality, even with the cooling delay of up to 240 hours. Cooling delay of 192 hours and 240 hours in ‘Galaxy’ apples not treated with 1-MCP should be avoided because it reduces the quality of fruits.