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Abstract The objective of this work was to quantify peach (Prunus persica) tree production in the Y-training and open-vase management systems, subjected to three summer pruning methods. The experiment was set up in a 2x3 factorial arrangement, with two management systems and three summer pruning methods (no summer pruning, summer pruning, and branch bending). The plants were arranged in two spacings: 1.5×5.0 m for the Y-training system, with 1,334 plants per hectare; and 4.0×5.0 m for open-vase system, with 500 plants per hectare. In the early summer of 2019, summer pruning was performed, being repeated in the three following years. In the branch bending treatment, new branches were twisted manually until reaching an angle of 110°. In the treatment without summer pruning, the branches were not removed. The Y-training system increases peach production. The methods of branch bending in summer and no prunning in summer provide an equivalent peach production, whereas the summer pruning treatment results in the lowest production.

Cultivation of stone fruit trees in many producing countries is traditionally carried out with low planting density and training in open plant systems (pots). However, the higher density systems and training with more compact mills, for example the 'leading system', have been providing better production. The objective of this work was to evaluate the phenological, vegetative, and productive characteristics of the peach cultivar Della Nona, subjected to various training systems. The work was conducted during two production cycles where three driving systems were evaluated: 'central leader' (5.0 m x 0.8 m, 2,500 plants ha-1), 'Y shape' (5.0 m x 1.5 m, 1,333 plants ha-1) and 'vase' (5.0 m x 3.5 m, 571 plants ha-1). We showed that phenological development was not influenced by the different training systems. The training system 'central leader' gave lower cup size, lower production, but higher productivity. We conclude that the 'central leader' training system adapts to the conditions of the region and shows high productivity for the peach cultivar Della Nona.

Abstract Traditional peach production regions provide adequate chill for satisfactorily bud’s flower break dormancy, in cultivars there developed. However, considering the expansion of the orchards in mild winter areas and the expected global trends to warmer conditions, the local development of cultivars became relevant. Based on this background, this study proposed to evaluate the performance of 33 peach and nectarine cultivars and selections in mild winter climate. Features associated to the vegetative development, phenology, productivity and fruit characteristics were measured in nine seasons, and the data analyzed by multivariate analysis of variance. Significant correlations between features were remarked. The Pillai and F tests presented significant results, highlighting significant differences among cultivars for almost all features. Peach and nectarine genotypes showed genetic diversity that may be accessed for use as cultivars, or parental for crosses. ‘IAC Aurora 1’, ‘IAC Aurora 2’, ‘IAC Centenário’, ‘IAC Douradão’, ‘IAC Jóia4’, ‘IAC Ouromel 3’, ‘IAC Régis’, ‘Diamante’, ‘Eldorado’, ‘FlordaPrince’, ‘Premier’ and ‘Tropic Beauty’ were the cultivars with the best results. A large number of selections showed promising results, emphasizing, the ‘IAC 680-177’, ‘IAC 1085-27’, ‘IAC 785-9’, ‘IAC 2982-31’, ‘IAC 4682-45’and ‘IAC 6882-84’.

Foram testados, durante dois anos sucessivos, indutores de brotação sobre o pessegueiro ‘SCS444 Nicoleto’, em Pedras Grandes, SC, Brasil. Os tratamentos foram: T1 – testemunha não tratada; T2 – cianamida hidrogenada; T3 – fertilizante foliar nitrogenado; T4 – Ca(NO3)2; T5 – fertilizante foliar nitrogenado + Ca(NO3)2; T6 – extrato de alho; T7 – extrato de alho + Ca(NO3)2. No primeiro ano foi observado um aumento significativo (p < 0,05) no número de flores abertas e na frutificação pós-raleio dos tratamentos T2, T3, T5 e T7 com relação à testemunha T1. No primeiro ano não foram observadas diferenças significativas na frutificação efetiva dos sete tratamentos. Entretanto, no segundo ano, que apresentou temperaturas hibernais relativamente mais baixas, foi observada uma diminuição significativa da frutificação efetiva dos tratamentos T2, T3, T4 e T5, que foram os que mais anteciparam a brotação vegetativa. Constatou-se que, no segundo ano, quanto maior o número de gemas vegetativas abertas durante a floração (devido a essa antecipação), menor foi a produção de frutos (R = − 0,94; p

ABSTRACT This study aimed to characterize the occurrence, duration, and intensity of the flushes of vegetative growth in two peach cultivars of Prunus persica L. Batsch, grown as a pioneer endeavor at a high-altitude tropical climate site in the State of Minas Gerais, Brazil. The observational experiment was carried out in 2017/18 and 2018/19 on the ‘Tropic Beauty’ and ‘BRS Kampai’ cultivars by an evaluation of the number and duration of flushes of vegetative growth during the year over two cycles. The number of fruit-bearing shoots, total number of leaves and shoot length were also assessed. At harvest, fruit load and diameter were determined and grouped into diameter ranges. The number of hours recorded at different temperature ranges, < 10.0 °C; 10.1-15.0 °C; 15.1-20.0 °C; 20.1-25.0 °C; > 25.1 °C, were summed separately and divided into daily and nightly periods. The peach tree has an unusual vegetative growth pattern when cultivated in a tropical area, which occurs in two flushes, with the first flush occurring from budbreak to fruit harvest between June and Sept, forming short shoots (less than 10 cm), with early shoot growth cessation, with a limited leaf number that can potentially diminish the supply of carbohydrates to the fruit, leading to smaller growth. The second flush occurs after harvest, between Oct and Dec, when there is an increase in daily temperature and precipitation, and no competition with fruits. Notabily, these second flush shoots grow with greater vigor and regularization of the growth cycle, forming fruit-bearing shoots with abundant leaf and flower buds for the next production cycle.

Abstract The objective of this work was to evaluate the effect of the use of rootstocks from clonal and seed production systems on the morphology of nursery peach trees of cultivar Granada. The experiment was carried out in a completely randomized design with five treatments ('Granada' scion grafted onto five rootstocks) and five replicates. The rootstocks from clonal production were the 'Okinawa' peach plant and the GKM-ELD-10-70, EF-SAU-10-78, and EF-SAU-10-87 peach genotypes kept in pots. The rootstocks from the seed production system came from peach seed of some scion varieties (mixed pits) used for canning production and propagated in a nursery field system. Shoot and root morphological variables were evaluated. The rootstock production system did not affect root volume. However, the nursery trees of the clonal rootstocks system kept in pots showed a higher percentage of water in the roots. The clonal rootstocks in the potted system do not affect most of the morphological traits of 'Granada' peach nursery trees; however, they induce a homogeneous root system and delay leaf abscission, besides not requiring root pruning.

Abstract A peach breeding program started in 1963, at the Experiment Station of Pelotas, nowadays Embrapa Clima Temperado, whose primary aim was developing cultivars adapted to mild winter conditions. Its first priority was to obtain cultivars of canning type fruits, and over the years, the fresh market cultivars acquired equal importance. This article analyzes the data of 84 fresh market cultivars, obtained in Pelotas, from 1964 to 2017, focusing on the following parameters: time of ripening, fruit development period, average fruit mass, number of fruits per tree, productivity per plant and total soluble solids. First, the data were tabulated, divided into two periods (1964-1984 and 1985-2017), and the descriptive statistical analysis was performed, followed by an analysis via mixed models and estimates of genetic progress via meta-analysis. The main results revealed a reduced fruit development period of the fresh market peaches belonging to that program. It was also observed a significant spread of the time of ripening (end of September or beginning of October until January), with a slight tendency for earliness. Genetic gain was observed for yield corresponding to 1.17 and 2.25% per year, for 1964-1984 and 1985-2017, respectively.

O objetivo deste trabalho foi avaliar a influência de variáveis térmicas, anteriores e posteriores à data estimada do início da ecodormência, sobre a variação nas datas médias de plena floração (DMPF) do pessegueiro, em Urussanga, SC, Brasil. A fase teórica de endodormência apresentou uma duração aproximada de 70 dias. A temperatura média das máximas dos 30 dias imediatamente anteriores ao início da ecodormência e a média das temperaturas médias dos 20 dias posteriores foram as variáveis que apresentaram as maiores correlações com a DMPF, com R = 0,88 (P ≤ 0,01) e R = −0,69 (P ≤ 0,05), respectivamente. As temperaturas máximas da fase de endodormência teórica e as temperaturas médias dos 20 dias iniciais da ecodormência, em um modelo de regressão linear, explicaram 96% das variações observadas na DMPF. As temperaturas inferiores a 16oC nos 40 dias iniciais da fase de endodormência, inferiores a 22oC nos 30 dias finais dessa fase, e acima de 13oC nos 20 dias iniciais da ecodormência apresentaram correlações negativas com a DMPF e explicaram conjuntamente 93% das variações observadas. Na fase final da endodormência, as temperaturas amenas (13ºC a 19oC) apresentaram maior influência sobre a antecipação da DMPF do que as inferiores a 13oC.

O conhecimento das condições microclimáticas locais e de sua influência na formação das gemas floríferas e vegetativas, na superação da endodormência, na fenologia, na produção e na qualidade de frutos do pessegueiro é fundamental para a implantação de variedades adaptadas à região, a fim de obter êxito com a espécie. O objetivo deste estudo foi avaliar a adaptabilidade de quatro cultivares de pessegueiro para as condições edafoclimáticas do município de Cerro Largo, RS. O experimento foi realizado durante os anos de 2019 e 2020. O delineamento experimental foi inteiramente casualizado, com quatro cultivares (BRS Kampai, BRS Regalo, Chimarrita e Eldorado) e nove repetições. As plantas estão dispostas em quatro linhas, com espaçamento de 2m entre plantas e 3,5m entre linhas, conduzidas em sistema Y. Foram avaliados: datas dos estádios fenológicos de florescimento e brotação, crescimento vegetativo, produção e atributos de qualidade dos frutos, bem como as condições meteorológicas. Nas condições avaliadas, BRS Kampai apresentou brotação e floração mais precoce. Já Eldorado teve maior duração dos períodos de floração e brotação. BRS Regalo apresentou maior crescimento vegetativo e produtividade de frutos, mostrando-se mais adaptada para a região de estudo. Chimarrita registrou maior massa média dos frutos, com maiores dimensões. Eldorado e BRS Regalo apresentaram os frutos mais firmes. BRS Kampai, BRS Regalo e Chimarrita apresentaram características de SST, ATT, pH e ratio previamente esperadas, o que proporciona frutos de qualidade para consumo in natura.

ABSTRACT The aim of this study was to evaluate the genotypes developed by the Peach Breeding Program at the Federal University of Viçosa, as regards to resistance to M. incognita. Six rootstocks genotypes propagated by cuttings (713-07, 713-13, 913-3, 913-6, 913-11 and 913-17) and two rootstocks propagated by seeds (‘Okinawa’ and hybrid between scion cultivars Aurora 2 x Aurora 1), were evaluated. The experimental design was randomized block design with five replicates and one plant per experimental units. After establishing the plants in pot, maintained in a greenhouse, this were inoculated with 11.000 juveniles + eggs of M. incognita. Evaluations were performed at 140 days after inoculation. The roots were evaluated and the number of galls and egg mass in the roots were determined. The eggs were extracted from each plant for quantification and determination of the Reproduction Factor (RF) of the nematode. The peach genotypes 913-3, 913-6, 913-11, 913-17 and 713-7 showed an immune reaction to M. incognita. Genotype 713-13 showed susceptible reaction to M. incognita. The hybrid between scion cultivars Aurora 2 x Aurora 1 confirmed susceptible.

Planting a peach orchard is highly expensive and may be influenced by variables such as attack by pathogens and diseases. Cultivar is one of the most important items within the production system and it is one of the few that may be modified without changes in costs. Current research evaluates the adaptability of peach cultivars 'Chimarrita', 'Eragil', 'Charme', 'Ouro', 'Seleção 01/08', 'FLA 8-1' and 'Della Nona' in the region of Campos Gerais PR Brazil. Experiment was conducted by randomized blocks, with seven treatments (cultivars) and eight replications. Variables analyzed comprised specific leaf area (cm² g-1), stalk diameter (mm), length of main stem (cm), volume of canopy (m³), incidence and severity of rust and early fruit, and percentage of attack by Grapholita molesta (Busck) (%). Cultivars Chimarrita and Ouro were more susceptible to the attack of grapholite (95.5% and 98%, respectively) and rust, with AACPS of 14.65 for Chimarrita and 15.67 for Ouro. Cultivars Charme, Seleção 01/08 and Eragil were more adapted for Campos Gerais, had little effect on growth variables such as the length of main stem, specific leaf area, stalk diameter and volume of canopy, even with the occurrence of diseases and pests which affect the culture. [ABSTRACT FROM AUTHOR]

Non-specific lipid transfer proteins (LTPs), present in multiple plant foods and pollens, are the predominant allergen in peach allergy in the Mediterranean region and may induce life-threatening allergic reactions. Although reasonably studied in adults, LTP allergy has been rarely described in children, and to the best of the author’s knowledge, natural tolerance development during childhood to this allergen has not been reported to date. The authors reported the case of a 21 month-old boy who presented urticaria and facial edema 15 minutes after eating a peach. Sensitization to peach LTP was confirmed by skin prick tests and specific IgE. At the age of 32 months, skin prick tests and specific IgE to peach LTP were negative, so a food challenge was performed. The child tolerated one medium-sized peach. Peach and peach-related fruits were reintroduced in the child’s diet. The authors discuss the relevance of regular allergy workup and dietary recommendations in children with LTP allergy.

Abstract This study aimed at evaluating production parameters of peach trees subject to different doses of potassium fertilization and at establishing the critical level of this nutrient in the soil and in peach tree leaves. The experiment was conducted in the 2016, 2017 and 2018 seasons in a commercial orchard located in Morro Redondo, Rio Grande do Sul state, Brazil. Peach trees of the cultivar Sensação were fertilized at the following doses: 0, 40, 80, 120 and 160 kg ha-1 K2O as potassium chloride applied to the surface of the soil. In the 3-year study, production per plant, number of fruit, fruit mass and fruit diameter were evaluated while soil and leaf samples were collected to undergo chemical analyses. Potassium fertilization in peach orchards increases levels of this nutrient in the 0-20 cm soil layer. Potassium fertilization via soil increased potassium contents in peach tree leaves. Productivity of peach trees responds to superficial potassium application via soil but it does not affect mean fruit mass. The critical level between relative productivity and potassium content in the soil could not be established while the one between production and potassium content of leaves of peach trees was 2.84%.

ABSTRACT: This research studied the effect of the inducers acibenzolar-S-Methyl, potassium phosphite, and potassium silicate on the leaf mineral concentration of peach. The experiment was carried out in Tezontepec, Puebla, in the years 2017 and 2018. The treatments consisted of the foliar application of the resistance inducers acibenzolar-S-Methyl, potassium phosphite, and potassium silicate. Inducers were applied at commercially recommended dose. The experimental design was in randomized blocks with four replicates. Foliar quantification of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, copper and silicon was carried out. The use of resistance inducers increases the leaf concentrations of calcium. The interaction of resistance inducers and years of application modified the foliar concentration of magnesium, phosphorus and sulfur in peaches.

ABSTRACT Thinning is a cultural practice that leads to balance between fruit yield and quality. It is carried out in a short period of time and requires qualified workforce, whose shortage ends up increasing costs. This study aimed at evaluating the thinning effect of metamitron on peach trees at different periods of time after bloom. The experiment was carried out in a commercial orchard of ‘Sensação’ peach trees located in Morro Redondo, Rio Grande do Sul (RS) state, Brazil, in 2015-2016 crops. Treatments were the application of 200 mg L-1 metamitron, 20, 30, 40, 50 and 60 days after full bloom (DAFB), and manual thinning 40 DAFB. Fruit abscission, effective fructification, period of manual and chemical thinning, number of fruits and yield per plant, mean fruit mass and fruit caliber were evaluated. When metamitron was applied 40 DAFB, percentages of fruit abscission and fruit set, besides the number of fruits, were similar to the ones found when manual thinning was carried out. The intensity of the thinning effect of metamitron in peach trees depends on the application period.

O pessegueiro apresenta um período de dormência no outono/inverno, superado pelo acúmulo de horas de frio (HF), variável com a cultivar. O objetivo desse trabalho foi quantificar a necessidade de frio na dormência de 18 cultivares de pessegueiro. Estacas de ‘Flor da Prince’, ‘Planalto’, ‘Vanguarda’, ‘Robidoux’, ‘Fascínio’, ‘Cerrito’, ‘Libra’, ‘Chimarrita’, ‘Atenas’, ‘Maciel’, ‘Kampai’, ‘Granada’, ‘Santa Aurea’, ‘Barbosa’, ‘Della Nona’, ‘Mandinho’, ‘Bonão’ e ‘Baby Gold’ foram coletadas a campo em abril/2019. Submeteu-se as estacas em câmaras incubadoras a 7,2°C e dois tempos de frio (200 e 400 HF). Após cada tempo de frio, transferiu-se as estacas para 20ºC para indução da brotação das gemas. Estratificou-se as cultivares quanto a exigência de frio em três classes: baixa (≤200 HF), média (201-400 HF) e alta (>400 HF). Relacionou-se a exigência de frio das cultivares com as datas de brotação e colheita a campo e zoneou-se as cultivares às regiões ecofisiográficas do RS, baseado no mapa de HF. ‘Flor da Prince’, ‘Vanguarda’, ‘Mandinho’, ‘Libra’, ‘Kampai’, ‘Granada’, ‘Bonão’ e ‘Cerrito’ necessitaram ≤200 HF para superar a dormência. ‘Fascínio’, ‘Baby Gold’, ‘Atenas’, ‘Maciel’, ‘Santa Aurea’ e ‘Chimarrita’ necessitaram de 201-400 HF. ‘Barbosa’, ‘Planalto’, ‘Della Nona’ e ‘Robidoux’ necessitaram >400 HF. As datas de brotação e colheita das cultivares a campo relacionaram-se com a exigência de frio dos genótipos. As cultivares de baixa exigência podem ser cultivadas em todo o Estado; as de média exigência limitam-se ao cultivo apenas na fronteira oeste; e as de alta exigência são recomendadas principalmente para Serra Gaúcha, Campos de Cima da Serra, parte do Planalto Médio e da Serra do Sudeste.

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Abstract The objective of this work was to evaluate the effect of chemical thinning with metamitron on fruit of the Maciel and Sensação peach (Prunus persica) tree cultivars, as well as to identify its relation to the carbohydrate content in their branches. The experimental design was randomized complete blocks, and the treatments were trees with no thinning, manual fruit thinning, and chemical thinning with 200 mg L-1 metamitron applied at 20, 40, and 60 days after full blooming. The evaluated variables were: abscission percentage, yield per plant, number of fruit, presence of lignin in fruit, and carbohydrate content in the branches. The carbohydrate content was evaluated in trees with and without chemical thinning seven days after the application of the product. The use of metamitron promotes fruit thinning in the ‘Maciel’ and ‘Sensação’ peach trees, with a decrease in the carbohydrate content in their branches. Metamitron application 20 and 40 days after full blooming favors fruit abscission in both studied cultivars.

En Jujuy existen 850 ha de durazneros (Prunus persica L.), alrededor de 800 ha se encuentran en los valles templados, donde hace unos años comenzaron a observarse plantas con síntomas de amarillamiento, enrojecimiento, enrollamiento y necrosis de hojas, defoliación prematura y acortamiento de entrenudos, incluso muerte de plantas. El agente causal es fitoplasma Argentinean Peach Yellows (arpy), del subgrupo 16Sr III-B, X-disease. La enfermedad se conoce como «amarillamiento del duraznero», una patología en expansión, sin antecedentes en el país, de la cual es importante conocer su epidemiología: presencia y dispersión en variedades introducidas y naturalizadas, caracterizar la sintomatología y su variación estacional, lo que es parte de los objetivos de este trabajo. Mediante prospecciones visuales realizadas en la temporada 2018-2019, se estimó la incidencia/prevalencia de esta patología en los valles áridos y templados. En valles áridos y en los valles templados altos no se registraron plantas con síntomas; en los valles templados bajos se visualizaron plantas enfermas de arpy y su diagnóstico confirmado en el laboratorio. Se observó variación estacional de la sintomatología: en primavera las plantas se presentaban parcial o totalmente afectadas, con acortamiento de entrenudos, hojas en escoba de bruja, amarillamiento, enrojecimiento y acartuchamiento de hojas basales; en verano el 60 % de ramas sintomáticas de la primavera precedente, muertas o en proceso, sin nuevos síntomas; en otoño muerte de brindillas de ramas sintomáticas y defoliación anticipada. De 25 lotes productivos evaluados en los cultivares Flordaking, Opedepe y Rojo Dos, se determinó una prevalencia del 100 %. Los mayores valores de incidencia se registraron en el cultivar Flordaking. En cuanto a la severidad, medida con una escala de 6 grados, del total de plantas prospectadas (8.871), se observaron los mayores grados en plantas de Flordaking, seguidas de Opedepe y Rojo Dos.

Monilinia fructicola is a fungal pathogen responsible for fruit brown rot in many species of the Prunus genus. The use of abiotic elicitors as phosphites is being studied for the induction of fruit resistance as an alternative to the use of synthetic fungicides. The aim of this work was to evaluate the effect of phosphites on the content of total phenols, chlorogenic acid and changes in susceptibility to M. fructicola in peach fruits. Peach fruits of the cultivars Flordaking and Elegant Lady were treated with potassium- and calcium-phosphites, and harvested at three development stages: green fruit (GF), pit hardening (PH) and harvest time (HT). After harvesting, half of them were inoculated with a conidia suspension of M. fructicola under laboratory conditions. Total phenols and chlorogenic acid content were assayed on the skin of the fruits. Results showed different behaviors according to the cultivar. In Flordaking, the phosphite treatment allowed an increase in the content of total phenols in the stages of GF and PH, but not for chlorogenic acid. In the presence of inoculum, chlorogenic acid decreased, but not the total phenols. The Elegant Lady did not show differences in the content of total phenols and chlorogenic acid after the phosphite treatments. Both metabolites exhibited a seasonal behavior.

Brown rot produced by Monilinia fructicola (MON) is the main disease that causes postharvest losses in peaches of Argentina. There is a public concern in reducing the use of synthetic fungicides. The objective of this work was to evaluate the effect of lemon essential oil (LO) and aqueous garlic extract (GE) on MON in vitro mycelial growth inhibition (INH). In a first trial a MON colony disc was placed in the middle of a Petri dish containing PDA 2%, or over the plate lid containing 1 mL of the following treatments: Control, LO 0.5%, LO 1%, LO 3% and Fludioxonil 0.02%. In a second trial, GE was obtained processing fresh garlic (cultivar Colorado) in a blender with tap water; 1 mL of garlic extract was placed in the cover of each plate, the treatments were: Control, GE 2.27%, GE 5.68%, GE 11.35% and Fludioxonil 0.02%, the MON colony was placed over the lid containing the extract. All concentrations of LO assayed and GE 11.35% showed INH > 90%. Following these results LO and GE could be evaluated in future trials as postharvest treatments on peach fruits for Monilinia fructicola control.

El duraznero es un cultivo de gran importancia económica y social dentro de los países del Cono Sur de Sudamérica. La evolución de este frutal se ha visto condicionada tanto por las particularidades edafoclimáticas, como por las culturales y las económicas de cada país. Sintetizar en un solo documento la situación actual y los distintos aspectos que caracterizan al cultivo de durazneros en Uruguay, Brasil y Argentina fue el objetivo en este trabajo. La incorporación de tecnología en todos los sentidos ha permitido una mejora en los rendimientos, por lo que la producción se ha mantenido a pesar de la reducción del área de plantación. Últimamente se ha dado un proceso de crecimiento en escala y concentración de la producción, aunque las características del cultivo lo siguen haciendo muy apto para el pequeño productor. Grandes esfuerzos de investigación canalizados a través de universidades e institutos especializados han permitido generar información local y regional de alto valor e impacto. La importancia del material genético para el éxito del sistema productivo es clave y la estrategia de generar cultivares con adaptación local ha sido tomada por la región, siendo creciente la disponibilidad de nuevos cultivares generados por los programas de mejoramiento locales. El enfoque de producción integrada ha tomado gran impulso y son cada vez más las alternativas productivas que se desarrollan buscando prescindir de los agroquímicos, principalmente en lo que respecta al control de plagas y enfermedades. La densidad de plantación se ha ido incrementando y los sistemas de conducción y poda están evolucionando hacia formas más simples y pasibles de ser mecanizadas. Numerosos son los desafíos que hay por delante, pero a su vez es grande la convicción, entre los equipos de investigación, de poder seguir aportando para una mayor y mejor disponibilidad de frutos de Prunus en las mesas de los consumidores.

Abstract 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

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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.

Abstract Among the factors that affect peach productivity is the proper nutrition of plants, being nitrogen (N) one of the main nutrients for the crop. Thus, the objective of the current study was to evaluate the effect of nitrogen fertilization on macronutrient leaf contents, plant development and production of different genotypes of peach trees cultivated at high planting density, seeking to recommend the most appropriate concentration. The experiment was conducted between 2016 and 2018 using peach selections ‘Cascata 1513’ and ‘Cascata 1067’ and with nitrogen fertilization concentrations (0, 60, 120 and 180 kg ha-1 of N). Pruning mass, trunk diameter, number of fruits per plant, average fruit mass, yield per plant, yield per hectare and leaf macronutrients were evaluated. The increase of N concentration increases the N content in leaves. For the conditions of this experiment the maximum production per plant was obtained for the highest dose of 180 Kg ha of N.

Abstract Early-ripening peach cultivars present difficulties in the process of natural germination of seeds. In order to solve this problem, the culture of embryos in vitro can be considered an alternative, in which seeds find conditions to complete germination and development in a satisfactory way. Different protocols and culture media have been tested to meet the nutritional needs of the embryo, but they still have problems and need to be optimized. The objective of this work was to test culture media and BAP concentrations in order to increase the germination percentage of embryos and viable ‘BRS Kampai’ peach seedlings, avoiding possible anomalies in the process. The experiment was carried out at the Laboratory of Tissue Culture – “Universidade Tecnológica Federal do Paraná”, Campus of Pato Branco. The experimental design used was randomized blocks, in 2x5 factorial, with four replicates, with plot being represented by 15 embryos. The culture media tested were MS and WPM with five BAP concentrations (0, 1, 2, 3 and 4 mg L-1). In the in vitro period, seed germination was evaluated through the attribution of scores, and embryo development, measuring the length of stem and main root. During the acclimatization period, seedlings were evaluated for survival, stem length, viable seedlings and rosette formation. Considering the conditions under which the experiment was conducted, it was concluded that MS culture medium with the addition of 1 mg L-1 of BAP allowed higher germination percentage and viable ‘BRS Kampai’ peach seedlings.

Técnicas que melhorem a eficiência do processo e reduzam o custo de operação são importantes ferramentas na redução dos custos. Dois dispositivos mecânicos foram utilizados para testar a eficiência no raleio de frutos e flores em pessegueiros e a influencia nas características produtivas e qualitativas dos frutos. O estudo foi realizado na cultivar Maciel em pomar comercial no município de Pelotas, Rio Grande do Sul, Brasil. Os tratamentos foram: raleio mecânico de flores com o equipamento Carpa Electro® e “derriçadeira”, raleio mecânico de frutos com o equipamento “derriçadeira” e raleio manual de frutos. O raleio mecânico associado ao repasse manual em pessegueiros pode ser uma alternativa viável ao raleio manual, pois reduz o tempo de execução desta prática. Os dois equipamentos podem ser utilizados para o raleio mecânico, pois não alteraram a produção por planta, o número de frutos por planta, a massa dos frutos, diâmetro dos frutos, as características físico-químicas e os compostos bioativos dos frutos.

Sob condições de inverno ameno, espécies frutíferas temperadas sofrem problemas agronômicos resultantes de brotamento e floração heterogêneo. O padrão de evolução da dormência e da brotação de pessegueiro foi estudado usando condições experimentais que forneceram plantas com 1) Condições naturais de inverno em clima temperado (CN), 2) Privação parcial de frio (PPF) e 3) Privação total de frio (PTF). A endodormência das gemas vegetativas foi caracterizada por meio do teste de estacas de gema única. As plantas com privação de frio, tanto parcial, como total, apresentaram evolução da dormência e taxa de brotação alterada em relação as plantas sob CN. Os padrões de brotação dependeram dos padrões de saída da endodormência das gemas, tanto no tempo quanto no espaço. Pelo comportamento observado na evolução da dormência e da brotação, podemos inferir que, em condições de inverno temperado, o gradiente de brotação tem origem na capacidade de crescimento das gemas após a saída da endodormência, enquanto que em condições de privação parcial de frio, a origem está na evolução diferencial da endodormência das gemas ao longo do ramo.

The multivariate analyses application and genetic divergence quantification can provide parameters that aid the selection of superior rootstocks. The objective of this study was to evaluate the technical feasibility of using the genetic diversity of the genus Prunus as a clonal rootstock of the peach cultivar ‘BRS-Libra’. The experimental orchard used was part of a national network for evaluation of rootstocks for prunaceous trees, under the general coordination of Embrapa Clima Temperado. The design was randomized and data were collected during the 2016/2017 production cycle. Physical analyses (trunk section area, average fruit mass), chemical analysis (soluble solids), and quantification of estimated productivity of the plants were performed. The data were subjected to the Shapiro-Wilk normality test at a 5% probability level, after which the grouping of the rootstocks was performed using the Unweighted Pair Group Method Using an Arithmetic Average (UPGMA) hierarchical method. The grouping resulted in the formation of five groups. The cultivars of group I, Mirabolano 29C and Marianna 2624, showed graft incompatibility with the evaluated cultivar scion. Similarly, cultivars of group II showed characteristic symptoms of graft incompatibility, resulting in poor development. Group III and IV were composed of cultivars that showed low and medium vigor, with good characteristics for use in orchards with high density, while the cultivars of the group V stood out because they showed high vigor, recommended for orchards with low density. The use of various rootstocks influenced the behavior, vigor and fruit production of the BRS Libra cultivar, with genetic divergence.

Zilli é um cultvar de pessegueiro originário de mutação espontânea do cv. Chimarrita, que produz frutos com polpa bicolor – amarela com uma faixa branca ao longo da sutura. A mutação foi identfcada em 2005 na propriedade de Agenor Zilli, no município de Descanso, SC, a 450m de alttude. Em 2008 foi introduzido e avaliado na Epagri/Estação Experimental de Videira, SC, a 830m de alttude. Além de mudança na coloração da polpa, a mutação também resultou na antecipação entre 7 e 20 dias da floração e até 9 dias na maturação em relação à Chimarrita, provavelmente decorrente de redução da exigência de frio hibernal. Em consequência disso, Zilli é mais suscetvel a danos por geadas tardias nas regiões mais frias, porém deverá ter uma adaptação melhor em regiões mais quentes (< 200 horas abaixo de 7,2oC), onde o cv. Chimarrita apresenta problemas de adaptação. Não foram observadas outras alterações causadas pela mutação. Pela alta qualidade dos frutos e pela forma inusitada da polpa, o cv. Zilli apresenta bom potencial de mercado, principalmente em regiões com poucas horas de frio hibernal.

Abstract Fruit juice does not have the same nutritional value as fresh fruit with regards to the vitamin, mineral and dietary fibre contents and the antioxidant properties. However, it can be part of a healthy diet if it is produced with the minimal addition of sugar. This study aimed to evaluate the performance of the FTIR-ATR technique to discriminate the authenticity (concerning the addition of other pulps) and amount of sugar in peach nectars. This technique is usually used in food analysis because it does not require sample preparation, is quick and allows for the determination of several parameters with a single sample aliquot. The nutritional information provided on the labels of 69 samples of 23 different brands of commercial peach juice, was analysed. The differences in the nutritional composition and in the ingredients were determined according to an analysis of the labels. The largest differences observed between the samples were the sugar contents, the percentages of pulp and the addition of other pulps. All samples were analysed by FTIR-ATR equipped with a controlled temperature flow-through cell. The spectral multivariate analysis suggested it was possible to identify differences in the amount of sugar present and identify the presence of fruit pulps other than peach.

Resumo O objetivo do presente estudo foi verificar o potencial da aplicação de revestimentos à base de fécula de mandioca (F), aditivados de extrato (E) de erva-mate (Ilex paraguariensis St. Hill), na conservação pós-colheita de pêssegos. Foram utilizados frutos cv. Della Nona e os tratamentos aplicados foram: frutos sem revestimento (Testemunha), frutos com revestimentos à base de fécula de mandioca aditivados de extrato de erva-mate nas concentrações de 0 g L-1 (F+0%E), 5 g L-1 (F+5%E), 10 g L-1 (F+10%E) e 15 g L-1 (F+15%E). Os frutos foram armazenados por 10 dias a 1 °C, com 95% de umidade relativa (UR). Para avaliação da qualidade pós-colheita dos frutos, foram realizadas análises físico-químicas, incluindo sólidos solúveis, acidez titulável, perda de massa e firmeza. Para avaliação do efeito in vitro dos revestimentos no crescimento do fungo Monilinia fructicola, agente causal da podridão parda, avaliou-se a germinação de conídios e a área abaixo da curva de crescimento micelial. Para avaliação do controle da podridão parda in vivo, determinou-se incidência (%) e índice de infecção, e as enzimas peroxidase e polifenoloxidase. Observou-se que o uso de revestimentos reduziu a perda de massa dos frutos em 50%, aumentou o teor de sólidos solúveis e intensificou a coloração vermelha dos frutos, tornando-os mais atraentes ao consumidor. Além disso, houve aumento da atividade da enzima peroxidase em frutos revestidos e o tratamento com aditivo de 15% de extrato de erva-mate inibiu o desenvolvimento de podridão parda nos pêssegos.

In the search for more efficient techniques for the propagation of peach cuttings, this study aimed to evaluate the rooting of hardwood cuttings of peach rootstock genotypes under different indolebutyric acid (IBA) concentrations. In the winter of 2016, the basal end of cuttings of genotypes 1701-1, 1701-2, 102-1, 102-2, 202-1 and 'Okinawa' were dipped into solutions with five concentrations of IBA (0, 1000, 2000, 3000 and 4000 mg mg L-1) for 5 seconds. The cuttings were then placed in sand in plastic trays and kept in a mist chamber. The experiment was arranged in a 6x5 factorial, completely randomized design, with 5 replications, and each plot consisted of eight cuttings. After 59 days, the variables related to rooting and root quality were evaluated. Genotypes 102-1 and 202-1 showed high adventitious rooting potential in hardwood cuttings, with 76.8 and 66.5% of rooting, respectively. The concentration of 2000 mg.L-1 of IBA acid can be recommended for the treatment of hardwood cuttings of the tested rootstocks for propagation in the winter.

Abstract: The objective of this work was to evaluate the effect of nitrogen fertilization on the mineral composition of leaves, initial growth, and yield of peach (Prunus persica) tree advanced selections grown at a high-planting density. The experiment was carried out between 2012 and 2015 in a randomized complete block design, with a combination of advanced selections of the 'Cascata 1513' and 'Cascata 1067' peach trees and of N fertilization doses (0, 30, 60, and 120 kg ha-1 N). Green weight after pruning, diameter, and increase of trunk diameter, canopy volume, plant height, branch length, number of buds per centimeter of shoot, chlorophyll index, leaf area, rust incidence, average production, number of fruit, and mass of fruit were evaluated. Genotype affects the vegetative growth and productive performance of peach trees. The application of N to dense peach orchards promotes a greater vegetative growth of the plants and increases the content of the nutrient in leaves. The initial production is affected by N fertilization. The recommendation of N fertilization made to date is insufficient for peach trees at high-density management systems of production.

For peach trees produced in southern Brazil, information about the influence of potassium fertilization on fruit quality remains scarce. This study set out to determine the physicochemical properties and bioactive compounds of peaches treated with different doses of potassium applied to the soil for three consecutive crop years. The experiment examined the Sensação cultivar in a commercial orchard in the municipality of Morro Redondo, Rio Grande do Sul, Brazil, during the 2016, 2017, and 2018 crop years. Peach trees of the Sensação cultivar were fertilized with potassium (K); doses of 0, 40, 80, 120, and 160 kg ha-1 of K2O in the form of potassium chloride were applied to the soil surface. After harvest, an assessment was made of the soluble solids (SS) content, titratable acid (TA) content, SS/TA ratio, pH levels, flesh color, skin and flesh firmness, total carotenoid content, total phenolic content, and antioxidant activity. The peaches' skin firmness, SS/TA ratio, and concentration of carotenoids responded to potassium fertilization, but only in some production cycles. Their color, flesh firmness, soluble solids, juice pH levels, total phenols, and antioxidant activity did not change with the application of potassium in the soil. [ABSTRACT FROM AUTHOR]

This study set out to assess the nutritional status of peach trees in the commercial peach-growing region of Pelotas, Rio Grande do Sul. The sample includes 65 peach orchards of the Maciel, Granada, Esmeralda, and Sensação cultivars in the municipalities of Pelotas, Canguçu, and Morro Redondo during the 2018 agricultural cycle. After drying and grinding the leaf samples for an analysis of their nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) content, the results were presented in frequency distributions divided into classes based on the nutrient requirements indicated for the crop in the region, in addition to the correlations between the nutrients. Greater deficiencies were observed in nitrogen, copper, iron, and zinc content. However, potassium content was found in the "above normal" class for most of the samples, and there were correlations between P/Ca, P/Cu, Ca/P, Ca/Mg, and Ca/B. An insufficient use of the tools to assess the nutritional status of the orchards was observed, especially the leaf diagnosis, which led to the inappropriate use of fertilizers and the consequent nutrient imbalance in the plants. [ABSTRACT FROM AUTHOR]

Techniques that improve process efficiency are important to reduce the operational cost of orchards. Two mechanical devices were tested to verify the efficiency of peach tree thinning and the influence on fruit production and quality characteristics. The experiment was conducted using the Maciel cultivar in a commercial orchard in Pelotas, Rio Grande do Sul, Brazil. The treatments consisted of mechanical flower blossom thinning using the Carpa ElectroTM and "trimming" equipment; mechanical fruit thinning using the "trimming" equipment; and manual fruit thinning. The mechanical thinning associated with manual thinning of peach trees may be a viable alternative to manual thinning since it reduces the execution time. Both equipment can be used for mechanical thinning since they didn't change the production per plant, number of fruits per plant, fruit mass, fruit diameter, physicochemical characteristics, and bioactive compounds of the fruits. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to evaluate the effect of shoot heading and of hand thinning in different development stages of flowers and fruits on the fruit production and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was performed during three crop years, under the conditions of the “Depressão Central” region in the state of Rio Grande do Sul, Brazil, and the treatments were: T1, heading of half of the mixed shoot; T2, heading of one third of the mixed shoot; T3, flower thinning in the pink bud stage; T4, thinning at full bloom; T5, thinning of fruit with 5 mm; T6, thinning of fruit with 20 mm; and T7, no thinning or heading (control). Fruit production and quality were evaluated. Plants with no thinning were more productive, but showed high frequency of fruits with a diameter smaller than 60 mm. Shoot heading reduced production per tree and resulted in small-sized fruit. Thinning time did not affect production, and fruit size was greater when thinning was performed at the bloom stage. 'BRS Kampai' peach trees can be thinned starting at bloom, which provides greater fruit size, with no production loss.

Worldwide, peach propagation has been performed mainly by grafting scions of desirable cultivars on rootstocks obtained from seeds. There are, however, other potential propagation methods not widely adopted due to the limited reports on the field performance of the resultant trees. This study addressed this knowledge gap and investigated the field performance of peach trees of the cultivar Maciel that were established in an orchard (5.0 m × 1.4 m spacing) in 2011. The trees were trained in a "Y" system, with seedlings from three propagation techniques: 1) Conventional System (CS) - vegetative bud grafting of the scion on the rootstock of the Okinawa cultivar obtained from seed; 2) Rootstock by Minicutting (RM) - vegetative bud grafting of the scion on the rootstock of the Okinawa cultivar obtained by minicutting in a semi-hydroponic system; 3) Self-Rooting (SR) - self-rooting of the scion in a semi-hydroponic system. The vegetative, productive, and fruit quality parameters were assessed during 2012 and 2013. The Maciel peach trees that were propagated by the SR technique were found to have similar or even superior field performance to those propagated by the CS. The RM propagation method was also found to be an important potential alternative to peach propagation, since this it combines two techniques (cutting and grafting) to reduce tree vigor, especially if the goal is high-density planting.

Abstract: The objective of this work was to evaluate the broad-sense heritability reaction to bacterial leaf spot (Xanthomonas arboricola pv. pruni), in peach tree populations obtained from directed crosses. Disease severity and defoliation of the genotypes were evaluated in field conditions, with posterior measurement of the healthy leaf area duration (HAD). The observed average heritability (0.51) indicates that the use of the evaluated genitors can be effective for the development of cultivars with higher resistance to the disease.

Os porta-enxertos constituem o sistema radicular das plantas enxertadas, interagem com os fatores bióticos e abióticos do solo e influenciam inúmeras características da cultivar-copa. No Rio Grande do Sul, estado maior produtor brasileiro de pêssegos, as cultivares tipo indústria ‘Aldrighi’ e ‘Capdeboscq’ foram bastante utilizadas como porta-enxerto até o final da década de 1970, devido a facilidade de obtenção de sementes e também pela ausência de porta-enxertos adequados. Hipotetizou-se que cultivares com características desejáveis de sistema radicular e lançadas para a finalidade porta-enxerto, como ‘Flordaguard’, ‘Nemaguard’ e ‘Okinawa’, aumentam o desempenho produtivo da cv. Maciel, comparativamente a ‘Aldrighi’ e ‘Capdeboscq’. O objetivo do presente trabalho foi avaliar os efeitos de cinco cultivares como porta-enxerto (Aldrighi, Capdeboscq, Flordaguard, Nemaguard e Okinawa) sobre a produção por planta, produtividade por hectare e eficiência produtiva do pessegueiro ‘Maciel’ por cinco anos consecutivos, em duas unidades de observação em Pelotas-RS, sendo uma delas em área com histórico de morte-precoce. As cultivares testadas como porta-enxerto do pessegueiro ‘Maciel’ apresentam eficiência produtiva, produção acumulada e produtividade acumulada, em cinco anos produtivos, similares entre si. O desempenho dos porta-enxertos avaliados foi bastante similar nas duas unidades de observação e nenhum sintoma de morte-precoce do pessegueiro foi verificado, nos primeiros seis anos de cultivo. As cultivares lançadas para a finalidade porta-enxerto - ‘Flordaguard’, ‘Nemaguard’ e ‘Okinawa’ - constituem alternativas de recomendação mais adequadas para a cultivar Maciel, na região persícola de Pelotas- RS.

Abstract: The objective of this work was to evaluate the effect of thinning with metamitron on the fruit yield and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was carried out in the municipality of Eldorado do Sul, in the state of Rio Grande do Sul, Brazil, in the 2016 and 2017 crop years. Treatments consisted of the application of 100, 200, 300, and 400 mg L-1 metamitron and of hand thinning 40 days after full bloom, besides control plants. Fruit abscission, effective fructification, number of fruits, and fruit yield per plant were evaluated. Regarding fruit quality, fresh fruit biomass, epidermis color, pulp firmness, soluble solids, total phenolic compounds, and antioxidant activity were assessed; fruits were also classified into diameter classes. For fruit abscission, the effect of the application of 100 mg L-1 metamitron is similar to that of hand thinning. Fruit yield and mean mass in all treatments with metamitron are similar to those obtained by hand thinning. The application of metamitron does not affect the fruit quality of peach trees. Chemical thinning with metamitron may be an alternative to hand thinning in peach trees used for the production of fruits for fresh consumption.

O fósforo faz parte de numerosos compostos orgânicos no metabolismo das plantas, como nucleotídeos e fosfoproteínas além de participar do metabolismo e armazenamento de energia. O objetivo do presente trabalho foi avaliar a resposta de pessegueiros cv. Sensação a adubação fosfatada e estabelecer o nível crítico deste nutriente no solo e nas folhas. O experimento foi conduzido nos ciclos 2016 e 2017 em um pomar comercial localizado no município de Morro Redondo/RS – Brasil. O delineamento experimental foi de blocos ao acaso com quatro repetições. Os pessegueiros foram adubados com doses crescentes de fósforo (P), sendo estas, 0, 20, 40, 60 e 80 kg ha-1 de P2O5 na forma de superfosfato triplo. Nos dois ciclos avaliados foram coletadas amostras de solo na camada de 0-20 cm e de folhas para determinação dos teores de minerais. Os dados obtidos, foram submetidos a análise de variância pelo teste F (P < 0,05), e quando os efeitos foram significativos, ajustadas as equações de regressão. A aplicação de P aumentou os teores deste nutriente no solo. Os teores foliares de P não foram afetados pela adubação, bem como a produtividade e os componentes de rendimento. Sendo assim, não foi possível estabelecer um nível crítico de P no solo e nas folhas de pessegueiros. Em solos onde os teores de P são classificados como médios e acima disso, não há a necessidade de se aplicar este nutriente.

O objetivo deste trabalho foi avaliar o desempenho de genótipos de pessegueiro e nectarineira nas condições do oeste de Santa Catarina. Cinco genótipos de pessegueiro ‘BRS Rubimel’, ‘Zilli’, ‘SCS423 Bonora’, ‘Seleção Epagri 02-40’ e ‘BRS Fascínio’ e as nectarinas 'Seleção Epagri 31-43', ‘SCS418 Julema’ e ‘Seleção Embrapa Necta 528’ foram avaliados nos municípios de Caibi, Cordilheira Alta (exceto 'BRS Fascínio') e Descanso, até o quarto ano. A colheita de ‘Seleção Epagri 31-43’, ‘SCS418 Julema’ e ‘SCS423 Bonora’ foi mais precoce, com início no segundo decêndio de setembro, apesar da floração um pouco mais tardia em comparação com 'Zilli' e ‘BRS Rubimel’. Em termos de produtividade, os destaques foram ‘SCS423 Bonora’, 'Zilli', ‘SCS418 Julema’ e 'Seleção Epagri 02-40' em Cordilheira Alta, ‘SCS423 Bonora’ em Caibi e ‘SCS423 Bonora’, 'Zilli' e ‘SCS418 Julema’ em Descanso. A massa média de frutos foi maior nos tratamentos 'Seleção Epagri 02-40' e 'Zilli' em Cordilheira Alta; ‘BRS Fascínio’, 'Seleção Epagri 02-40' e 'Zilli' em Caibi; e ‘BRS Fascínio’ e 'Seleção Epagri 02-40 'em Descanso. O pessegueiro ‘SCS423 Bonora’ e a nectarineira ‘SCS418 Julema’, dentro do seu grupo, combinam características desejáveis de precocidade, tamanho dos frutos e produtividade.

No ano de 2013 foi registrada uma floração precoce e intensa em pessegueiro, em época atípica, no município de Urussanga, SC, Brasil. Vinte por cento dos acessos de uma coleção de pessegueiro apresentaram plena floração em meados de abril, quando normalmente esta ocorre nos meses de julho e agosto. As faixas térmicas com temperaturas entre 16,0 e 19,0oC e inferiores a 19,0oC (13,0 a 19,0oC), em um período de 49 dias entre fevereiro e março, foram as que mais se relacionaram com a antecipação da plena floração no referido ano, com correlações de -0,92 (p

Peach brown rot, caused by the Monilinia fructicola fungus, is the main disease affecting peach crops, and it is mainly controlled via frequent fungicide applications. This study aimed at searching for alternatives to the intensive use of chemicals, evaluating silicon doses to control pre and postharvest peach brown rot and their influence on maturation parameters and fruit quality. Treatments consisted of control (water) and sodium metasilicate doses (2 g L-1, 4 g L-1, 6 g L-1, 8 g L-1 and 10 g L-1 of water). The following assessments were made: spore germination and in vitro mycelial growth, brown rot incidence, soluble solids, titratable acidity, flesh firmness, total polyphenol content and fruit ethylene production and respiration rate. The 2 g L-1 dose reduced spore germination by 95 %. Doses of 6 g L-1 and 8 g L-1 satisfactorily reduced the disease incidence in the field, with 77 % and 89.2 % control, respectively. Sodium metasilicate resulted in the maintenance of great fruit firmness, reduced respiration and ethylene production and increased total polyphenol synthesis, but it did not influence the titratable acidity or soluble solids. Applying 6 g L-1 may potentially control pre and postharvest peach brown rot, besides increasing the total polyphenol synthesis and maintaining a higher flesh firmness.

Abstract: The objective of this work was to evaluate the productive and vegetative performance of the Maciel and Chimarrita peach tree cultivars grafted on six rootstocks, in a replanting area. The experiment was carried out in an area that had been previously cultivated with peach trees for more than 15 years in the municipality of Eldorado do Sul, in the state of Rio Grande do Sul, Brazil. The Maciel and Chimarrita peach tree cultivars were grafted on 'Aldrighi', 'Capdeboscq', 'Okinawa', 'Flordaguard', 'Nemaguard', and 'Umezeiro'. The 'Umezeiro' rootstock caused high plant mortality in both scions, as well as low productivity and higher alternate bearing; it also affected the qualitative and ripening attributes of the fruits of 'Chimarrita'. The 'Aldrighi', 'Capdeboscq', 'Okinawa', 'Flordaguard', and 'Nemaguard' rootstocks induced a similar yield in both scions. The trunk cross-sectional area (TCSA) did not differ between rootstocks in 'Maciel', but in 'Chimarrita', TCSA was higher on 'Flordaguard' than on 'Umezeiro' in some seasons. Regarding the average of rootstocks, 'Maciel' showed higher TCSA, pruning mass, and average yield than 'Chimarrita', as well as changes in qualitative and ripening attributes. The Maciel cultivar shows the best productive performance in replanting areas, and the 'Capdeboscq' and 'Aldrighi' rootstocks induce satisfactory agronomic performance.