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The objective of this research was to evaluate the technical feasibility of SPAD index in the diagnosis of N status in ‘Esmeralda’ peach. The field trial, with five N rates applied to the soil (0, 40, 80, 120 and 160 kg ha-1 of N as urea form) was conducted in a randomized block design with four replications. During the years 2014, 2015, 2016 and 2017, SPAD readings were carried out with a Minolta SPAD-502 chlorophyll meter, in the leaf middle part, in 40 leaves per plot. The leaf N content determination was performed in CHN-S Elemental Analyzer. SPAD index and leaf N content increased in a linear way in response to increasing N rates applied in soil. There was a positive linear correlation between SPAD index and N concentration in leaves (0.652; 0.756; 0.762 and 0.767, p

Potassium (K) fertilization may affect peach quality and preservation. This study aimed at evaluating the effect of doses of K on physico-chemical and functional characteristics of "Sensação" peaches in the postharvest period. Mass loss, pulp color, total solublesolids, titratable acidity, pH, pulp and skin firmness, total concentrations of phenolic compounds and carotenoids and antioxidant activity were evaluated in fruits. The experiment was a randomized block design in a 5x3 factorial scheme, five doses of fertilizers (0, 40, 80, 120 and 160 Kg ha-1K2O) and three storage periods (harvest day, 10 days and 20 days in cold storage at 1±1ºC, followed by a day of simulated commercialization at 20±1ºC). Mass loss, pulp firmness, phenolic compounds, antioxidant activity and carotenoids decreased when fruit underwent cold storage, independent of the dosage of K fertilization. Doses of40 and160 kg ha-1K2O applied to the soil lead to a larger number of phenolic compoundsand higher antioxidant activity in fruits at harvest time. After cold storage, fertilization with160 kg ha-1K2O exhibited the highest antioxidant activity and the lowest mass loss in fruits. Increase in doses of K strengthened the color of peach pulp. Made available in DSpace on 2021-04-16T17:35:55Z (GMT). No. of bitstreams: 1 barreto-15-3-2021-319-324.pdf: 946731 bytes, checksum: 21c760837ace5c819da8c39831554d99 (MD5) Previous issue date: 2021

This study aimed at evaluating the quality of peaches borne by the cultivar BRS Kampai when cooled at intermittent temperatures throughout storage. They were stored at 1°C and relative humidity between 80% and 90% in a cold storage chamber. The following treatments were applied: T1 - fruit stored at 1±0.5°C; T2 - fruit stored at 1±0.5°C and increase in temperature every five days to 25°C; and T3 - fruit stored at 1±0.5°C and increase in temperature every seven days to 25°C. Fruit were submitted to increase in temperature when they were withdrawn from the cold storage chamber and kept in a heated room. Evaluations were conducted when fruit were harvested, after 10 cold storage days and 2 days of commercialization simulation at 25ºC (10+2) and after 20 cold storage days and 2 days of commercialization simulation at 25ºC (20+2). Peaches were evaluated in terms of mass loss, pulp firmness, soluble solids, titratable acidity, pH and epidermis color. T1 exhibited higher mass loss, higher soluble solid content and higher pulp firmness after 20 cold storage days, by comparison with the other treatments. T2 led to lower mass loss after 20 cold storage days than the ones of the other treatments. However, T2 also showed higher loss of pulp firmness in the same period. The use of intermittent temperatures throughout storage of ?BRS Kampai? peaches may be an alternative to extend their post-harvest period. Made available in DSpace on 2021-09-23T02:15:02Z (GMT). No. of bitstreams: 1 Artigo-Intermittent-temperatures-in-the-conservation.pdf: 391144 bytes, checksum: bcb33666229292d3011f5ad425f848f3 (MD5) Previous issue date: 2021

Para pessegueiros produzidos na região sul do Brasil ainda são escassas as informações sobre a influência da adubação potássica sobre a qualidade dos frutos. Deste modo, o presente trabalho teve como objetivo avaliar os atributos físico-químicos e compostos bioativos dos frutos de pessegueiros submetidos a diferentes doses de potássio aplicadas no solo por três safras consecutivas. O experimento foi realizado estudando a cultivar Sensação em um pomar comercial no município de Morro Redondo, RS ? Brasil, durante as safras de 2016, 2017 e 2018. Os pessegueiros da cultivar Sensação foram adubados com potássio (K) nas doses de 0, 40, 80, 120 e 160 kg ha-1 de K2O na forma de cloreto de potássio, aplicadas na superfície do solo. Após a colheita foram determinados os teores de sólidos solúveis (SS), acidez titulável (AT), relação SS/AT, pH, coloração da polpa, firmeza da epiderme e da polpa, teor de carotenoides totais, compostos fenólicos totais e atividade antioxidante. A firmeza da epiderme, a relação SS/AT e a concentração de carotenoides dos pêssegos responderam à adubação potássica, mas apenas em alguns ciclos de produção. Os parâmetros de coloração, firmeza da polpa, sólidos solúveis, pH do suco, fenóis totais e atividade antioxidante dos pêssegos não alteraram em decorrência da aplicação de potássio ao solo. Made available in DSpace on 2021-01-19T09:02:24Z (GMT). No. of bitstreams: 1 Artigo-Adubacao-potassica-na-qualidade-de-frutos-de-pessegueiro.pdf: 92009 bytes, checksum: d028a705b6486a58e3ccbff546a879aa (MD5) Previous issue date: 2020

Entre os fatores que afetam a produtividade dos pessegueiros, está a nutrição adequada das plantas, sendo o nitrogênio (N) um dos nutrientes primordiais para a cultura. Deste modo, o objetivo do presente trabalho foi avaliar o efeito da adubação nitrogenada de manutenção nos teores foliares de macronutrientes, no crescimento das plantas e na produção de diferentes genótipos de pessegueiros cultivados em alta densidade de plantio, buscando-se recomendar a concentração mais adequada. O experimento foi conduzido entre 2016 e 2018, com seleções avançadas de pessegueiros "Cascata 1513" e "Cascata 1067", e com concentrações de adubação nitrogenada (0; 60; 120 e 180 kg ha-1 de N). Avaliaram-se: massa de poda, diâmetro de tronco, número de frutos por planta, massa dos frutos, produção por planta e teor de macronutrientes nas folhas. O incremento das concentrações de N aumenta o teor do N nas folhas. Para as condições deste experimento, a máxima produção por planta foi obtida para a maior dose de 180 kg ha de N. Made available in DSpace on 2020-11-21T09:15:45Z (GMT). No. of bitstreams: 1 0100-2945-rbf-42-6-e-629.pdf: 578387 bytes, checksum: 25a81bb2e5674abecf7154188600bb31 (MD5) Previous issue date: 2020