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Interferência das plantas daninhas por nutriente em cenoura cultivada com e sem mulch de aveia-preta
No full textThe interaction with weeds jeopardizes the nutrients accumulation in the carrots’ plants. The mulch can reducecompetition effects and provide advantages to the cultivation. This research aimed to assess the black oat(Avena strigosa Schreb.) hay mulch effect on dry matter accumulation of weeds and nutrients (N, P, K, andS) accumulation in the carrots plants cultivar “Alvorada.” The experiments were set during the crop seasons2016/2017 and 2017/2018 in a randomized-block design with a factorial scheme 2 x 5, with five repetitions. Thefirst factor corresponded to soil cover (with or without mulch), and the second factor, to the interaction timewith weeds (0, 15, 30, 60, and 120 days after emergence). The interaction with the weed community reducednutrients absorption and dry matter accumulation in the roots of the carrot’s plants. Interference with nutrientsabsorption was more intense in crops without black oat hay mulch than with mulch. Mulch can reduce weeds’dry mass by 75.6% during the entire culture cycle. Therefore black oak oat mulch reduces the weed interferenceallowing higher nutrients accumulation and roots biomass in the carrots plants cultivar “Alvorada.”A convivência com as plantas daninhas prejudica o acúmulo de nutrientes nas plantas de cenoura, porém, o mulch pode reduzir os efeitos da competição e proporcionar vantagens a cultura de interesse. Este trabalho objetivou avaliar o uso do mulch de palha de aveia-preta (Avena strigosa Schreb.) no acúmulo de massa seca de plantas daninhas e no acúmulo de nutrientes (N, P, K e S) nas plantas de cenoura da cultivar ‘Alvorada’. Os experimentos foram instalados nas estações de cultivo 2016/2017 e 2017/2018, em delineamento em blocos ao acaso em esquema fatorial 2 x 5, com 5 repetições. O primeiro fator correspondeu a cobertura do solo (com e sem mulch) e o segundo fator aos períodos de convivência com plantas daninhas (0, 15, 30, 60 e 120 dias após a emergência). A convivência com a comunidade infestante causou redução na absorção dos nutrientes e no acumulo de massa seca das raízes das plantas de cenoura, mais intensamente nos cultivos sem o mulch do que nos cultivos com mulch da palha de aveia preta. O uso do mulch pode reduzir em até 75.6% a massa seca das plantas daninhas durante todo o ciclo da cultura. Portanto, o uso de mulch de palha de aveia preta reduz a mato interferência e permite maior acúmulo de nutrientes e de biomassa nas raízes das plantas de cenoura da cultivar ‘Alvorad
Process of soil salinization as a function of watermelon mineral fertilization
Get PDFThe watermelon (Citrullus lanatus L.) is a cucurbitaceous plant of great social and economic importance in Brazil, especially in the north-eastern region. However, anthropic actions through the practice of irrigation, fertigation and fertilization in an inadequate way, have potentiated the salinization of the soil becoming this one of the main factors that limit the production and the quality of the fruits. In this work, the effects of the application of mineral fertilization on the salinization of soil cultivated with watermelon were evaluated. The experiment was performed in the city of Petrolina-PE, with four repetitions, using five treatments: (T0) no fertilization, (T1) NPK fertilization, (T2) average dose of NPK practiced by producers, (T3) maximum dose of NPK from producers having potassium chloride as a source of potassium and (T4) maximum dose of NPK from producers having potassium sulfate as a source of potassium, at two different depths: 0.00 - 0.20 m and 0.20 - 0.60 m. The soil chemical attributes analyzed were pH, electrical conductivity (EC), organic matter, phosphorus, potassium, sodium, calcium and magnesium. The increase in the continuous application of mineral fertilizers raised the electrical conductivity values of the soil to levels prejudicial to the crop.The watermelon (Citrullus lanatus L.) is a cucurbitaceous plant of great social and economic importance in Brazil, especially in the north-eastern region. However, anthropic actions through the practice of irrigation, fertigation and fertilization in an inadequate way, have potentiated the salinization of the soil becoming this one of the main factors that limit the production and the quality of the fruits. In this work, the effects of the application of mineral fertilization on the salinization of soil cultivated with watermelon were evaluated. The experiment was performed in the city of Petrolina-PE, with four repetitions, using five treatments: (T0) no fertilization, (T1) NPK fertilization, (T2) average dose of NPK practiced by producers, (T3) maximum dose of NPK from producers having potassium chloride as a source of potassium and (T4) maximum dose of NPK from producers having potassium sulfate as a source of potassium, at two different depths: 0.00 - 0.20 m and 0.20 - 0.60 m. The soil chemical attributes analyzed were pH, electrical conductivity (EC), organic matter, phosphorus, potassium, sodium, calcium and magnesium. The increase in the continuous application of mineral fertilizers raised the electrical conductivity values of the soil to levels prejudicial to the crop
In vitro regeneration of hybrid Dendrobium sect. Spatulata through pseudobulb segment culture
Get PDFThe low rate of Dendrobium regeneration through seed culture is a significant limitation of mass propagation development in new hybrids. An efficient protocol of in vitro regeneration through pseudobulb segment culture has been established for Dendrobium ‘Danny Dame’. Leaves and roots of seven-month-old seedlings were detached from the pseudobulb. Unsegmented pseudobulb and segments of apical, medial, and basal excised from seedlings. The four types of explants were cultured on Murashige and Skoog (MS) basal medium supplemented with different combinations of 1-naphthaleneacetic acid (NAA) and 6-benzyl amino purine (BAP). The highest number of shoots was observed in 1 mg L-1 BAP and 0.1 mg L-1 NAA using unsegmented pseudobulb explant after 2 months of culture. The unsegmented pseudobulb had a higher survivability rate and the number of shoots per explant than segmented pseudobulbs. However, if accumulated, segmented pseudobulbs can produce the number of shoots 2-4 times more than unsegmented pseudobulbs. The segment that had the highest average number of shoots was the basal segment. Two types of shoots were observed, both single shoot and multi shoot. The new shoots formation was developed from protuberance and or axillary bud. Roots were kept to grow only on the basal part of unsegmented explants and basal segment
Efeitos de fontes de pólen na qualidade de castanhas produzidas por cultivares de noz-pecã Kiowa e Barton
No full textSelection of pecan cultivars and their pollinizers is essential to reach maximum potential of production. Synchrony of blooming periods of cultivars may not be enough to ensure nut quality because of the xenia effect. This study aimed at evaluating effects of different pollinizers on dimensions and yields of fruit borne by cultivars Kiowa and Barton. Both cultivars were submitted to six treatments. Kiowa: no pollination, free pollination, self-pollination and pollination controlled by pollen from cultivars Cape Fear, Pawnee and Desirable. Barton: no pollination, free pollination, self-pollination and pollination controlled by pollen from cultivars Melhorada, Jackson and Success. Self-pollination decreased dimensions and yields of fruit and kernels. Pollen from different cultivars was found to exhibit positive and negative xenia effect on fruit characteristics. The largest fruit and the highest yield of kernels were reached when ‘Kiowa’ was pollinized with ‘Desirable’ and ‘Barton’ was pollinized with ‘Success’.A seleção de cultivares de noz-pecã e seus polinizadores é essencial para atingir o máximo potencial de produção. A sincronia dos períodos de floração das cultivares pode não ser suficiente para garantir a qualidade da castanha devido ao efeito xenia. O objetivo deste trabalho foi avaliar os efeitos de diferentes polinizadores nas dimensões e produtividade dos frutos das cultivares Kiowa e Barton. Ambas as cultivares foram submetidas a seis tratamentos. Kiowa: sem polinização, polinização livre, autopolinização e polinização controlada por pólen das cultivares Cape Fear, Pawnee e Desmable. Barton: sem polinização, polinização livre, autopolinização e polinização controlada por pólen das cultivares Melhorada, Jackson e Success. A autopolinização diminuiu as dimensões e a produção de frutos e grãos. Pólen de diferentes cultivares exibiu efeito xenia positivo e negativo sobre as características dos frutos. O maior fruto e a maior produção de grãos foram alcançados quando \u27Kiowa\u27 foi polinizado com \u27Desejável\u27 e \u27Barton\u27 foi polinizado com \u27Sucesso\u27.  
Lettuce weed control with prior soil solarization
Get PDFLettuce is a leafy crop appreciated for the supply of nutrients that favor the immune system. However, like other crops, it is subject to weed interference. Due to its low competitiveness and the impacts of herbicides, it is necessary to search new ways to control weeds. This work aims to determine the effects of solarization on weed control and on the productivity of \u27Verônica\u27 lettuce with or without soil revolving after solarization (SRAS). The experimental design was randomized blocks in a factorial scheme 7x2 with four replications. The beds were weeded, irrigated and covered with 150 µm-thick transparent polyethylene in different periods (first factor): five solarization periods (75, 60, 45, 30, and 15 days prior to planting) and two controls (without and with weeds), with or without SRAS (second factor). Weed phytosociology (frequency, density and relative dominance, importance value index, and relative importance) and lettuce productivity were evaluated. The control of the weed community (with a predominance of Java grass, Indian goosegrass, and crabgrass) with solarization is not efficient. However, the non-SRAS treatment decreases the density of some weeds and positively affects the productivity and commercial characteristics of lettuce.A alface é uma cultura folhosa apreciada pelo aporte de nutrientes que favorecem o sistema imunológico. Porém, como outras culturas, está sujeita à interferência de plantas daninhas. Devido à sua baixa competição e os impactos dos herbicidas, é necessário procurar novas formas de controle dessas plantas. Este trabalho teve por objetivos determinar o efeito da solarização no controle de plantas daninhas e na produtividade da alface ‘Verônica’, com ou sem revolvimento do solo após a solarização (RSAS). O experimento foi instalado em campo na UNESP-Jaboticabal, SP, em delineamento em blocos casualizados, com quatro repetições e esquema fatorial, sendo um fator cinco períodos de solarização (75, 60, 45, 30 e 15 dias anteriores ao plantio) e duas testemunhas (sem e com plantas daninhas), e outro fator com ou sem RSAS. Foi avaliada a fitossociologia das plantas daninhas (frequência, densidade e dominância relativa, índice de valor de importância e importância relativa) e a produtividade da alface. O controle da comunidade infestante (predominância de tiririca, capim-pé-de-galinha e capim-colchão) com a solarização não foi eficiente, no entanto o não RSAS diminuiu a densidade de algumas plantas daninhas e afetou positivamente a produtividade e caraterísticas comerciais da alface
O Acúmulo de macronutrientes em bulbos de cebola em função de épocas de aplicação de enxofre em condição tropical de baixa altitude
No full textThe amount of nutrients extracted by the bulbs represents an important component of nutrient removal from the soil, and its evaluation should be used to define the amount of nutrients to be replenished in the soil, through fertilization programs. The objective of the present study was to verify the accumulation of nutrients in onion bulbs due to the application of sulfur in different phenological stages. The experiments were carried out in a completely randomized design, in a 2 x 5 x 2 factorial scheme, with two cultivars (Dulciana and Vulkana), five S application times (control, at transplanting, at 6 to 7 leaves, at differentiation, and at bulbification) and 2 years of cultivation, with four replicates. After curing, ten bulbs were selected from each treatment, one per random repetition of each commercial plot formed by 20 bulbs from the field experiment, which were identified and taken to a nutrient analysis laboratory. Subsequently, the amount accumulated in the bulb of the content of each nutrient in the plant tissue was determined. Fertilization with sulfur promotes greater accumulation of K and N. The order of nutrient extraction in the presence of sulfur was K> N> P> S> Ca> Mg. The largest accumulations of sulfur in the bulb occurred when applied at the bulbification stage for both cultivars.A quantidade de nutrientes importantes para a avaliação dos bulbos deve ser utilizada para definir a quantidade de nutrientes do solo, meio de programas de adubação. Os diferentes estudos para verificar o acúmulo de nutrientes nos bulbos de cebola em função de aplicação de objetivo em estádios fenológicos. As épocas foram realizadas em sistema convencional, em delineamento inteiramente casualizado, em esquema de fato 2 x 5 x 2, com duas cultivares (Dulciana e Vulkana), em cinco aplicações de aplicação de S (Testemunha; Transplantio; estádio de 6 a 7 folhas; tecnologia de meditação plena dos bulbos e cultivo com quatro) e Após a cura escolheram-se quatro (4) bulbos de cada tratamento, um por repetição de experimentos comerciais foram feitos por 20 bulbos provenientes de experimentos de campo, os quais foram identificados de cada um deles e levados a um laboratório de nutrientes. Posteriormente, determinou-se a quantidade acumulada no bulbo do teor de cada nutriente no tecido. A adubação com enxofre promove maior acúmulo K e N. A ordem de transporte de nutrientes na presença de foi de K> N> P> S> Ca> Mg. Os maiores acúmulos de enxofre no bulbo para duas cultivares. A adubação com enxofre promove maior acúmulo K e N. A ordem de transporte de nutrientes na presença de foi de K> N> P> S> Ca> Mg. Os maiores acúmulos de enxofre no bulbo para duas cultivares. A adubação com enxofre promove maior acúmulo K e N. A ordem de transporte de nutrientes na presença de foi de K> N> P> S> Ca> Mg. Os maiores acúmulos de enxofre no bulbo para duas cultivares
Exigências térmicas e estimativas do número de folhas de Annona squamosa L. em condições de sombreamento
No full textThe objective of this study was to determine the thermal requirements and compare methods for estimatingleaf emergence in Annona squamosa L. under different shading conditions during the dry and rainy seasonsin a transition region between the Cerrado Amazon biomes, Mato Grosso, Brazil. Seedlings were grown underfull-sun conditions (reference) and black polyolefin screens with 35%, 50%, 65%, and 80% attenuation of globalradiation. Basal temperatures were determined using the method of least standard deviation; accumulatedthermal sum was estimated using the method described in Ometto (1981); the relationship between number ofleaves and thermal sum were evaluated using the phyllochron and Wang & Engel (1998) models. The minimumand maximum basal temperatures for the growth of A. squamosa were 11.0 and 38.0 °C, respectively. Theaccumulated thermal sum presented small variation between shading conditions and seasons, resulting inmeans of 1744±44 and 4434±118 degree-days at 113 and 260 days after transplanting (DAT), corresponding tothe end of the dry and rainy seasons, respectively. The thermal requirement for leaf emergence varied amongthe different shading conditions, with higher phyllochrons under full sun conditions and 80% shading (109.8 °Cday leaf-1) and lower phyllochrons under 50% shading (91.74 °C day leaf-1). The phyllochron model presentedhigher efficiency in estimating leaf emergence compared to the Wang & Engel model. Growing A. squamosaseedlings under 50% shading is recommended as it resulted in higher degree-day accumulation and lowerphyllochron for leaf emergence.Objetivou-se obter as exigências térmicas e a emissão de folhas de Annona squamosa L., em diferentes condições de sombreamento, nas estações seca e chuvosa da região (entre 05/2020 e 02/2021) de transição Cerrado-Amazônia de Mato Grosso. As mudas foram produzidas sob pleno sol (referência) e telas poliolefinas pretas de 35, 50, 65 e 80% de atenuação da radiação global. As temperaturas basais foram determinadas pelo método do menor desvio-padrão e a soma térmica acumulada estimada pelo método de Ometto; as relações entre o número de folhas e a soma térmica foram obtidas pelo método do filocrono e de Wang e Engel. As temperaturas basais máxima e mínima de Annona squamosa L. foram de 38 e 11°C, respectivamente. A soma térmica acumulada apresentou pequena variação entre as condições de sombreamento e estação hídrica, gerando médias de 1744±44 e 4434±118 graus dias, aos 113 e 260 dias após o transplantio (DAT), correspondentes aos finais das estações seca e chuvosa, respectivamente. A exigência térmica para emissão de folhas apresentou variação entre ambientes, com maiores filocronos em pleno sol e 80% de sombreamento (109,8 °C dia-1 folha-1) e menores em 50% de sombreamento (91,74 °C dia-1 folha-1). O método do filocrono apresentou maior eficiência na estimativa do surgimento de folhas quando comparado com o método de Wang e Engel. A produção de mudas de Annona squamosa L. sob sombreamento de 50% é a mais recomendada, promovendo maior acúmulo de graus-dia e menor filocrono para surgimento de uma folha
Shading and controlled-release fertilizer in the production of Oenocarpus bataua Mart. Seedlings
Get PDFWhen associated an adequate shading and nutrition the seedlings to reach characteristics that allow them tosurvive in the field and increase production. Thus, this work aimed to evaluate the production of Oenocarpusbataua seedlings in response to different shade environments and controlled-release fertilizer doses. Thestudy was carried out from at the Embrapa nursery located in the municipality of Rio Branco, Acre state. Theexperimental design was complete randomized blocks with three replications and six plants per plot. Thetreatments were distributed according to a 4 x 5 factorial scheme, i.e., four shade environments (20%, 30%, 50%and 75%) and five CRF doses (0.0, 1.5, 3.0, 4.5 and 6.0 kg m–3) mixed with the substrate. Biometric, biomass andquality variables were evaluated at 305 days after transplanting. The ANOVA was applied for the qualitativefactor and regression analysis was performed for the quantitative factor, both at 5% probability. The treatmentswere grouped by analyzing canonical variables, a multivariate statistical and realized the Pearson’s correlationbetween variables was determined through correlation networks. The shading environment and the controlledreleasefertilizer positively influenced the growth and quality of Oenocarpus bataua seedlings. The seedlings ofOenocarpus bataua have better biometric characteristics produced in a nursery with 50% shading. Oenocarpusbataua seedlings show better quality when 3.88 kg m-3 of controlled release fertilizer are used
Agronomic, Physiological, and Post-Harvest Aspects of Different Blueberry Cultivars Treated with Silicon
Get PDFThe objective of this study was to evaluate the effect of foliar application of silicon in different blueberry (Vaccinium myrtillus) cultivars. The treatments were installed in a factorial design with six replications, and consisted of three different cultivars (Brightwell, Beckblue and Climax) with or without regular application of silicon via foliar, using silicon oxide at 1.5 g L-1. It was evaluated the following plant attributes: leaf area, chlorophyll fluorescence, and phenylalanine ammonia lyase activity, meanwhile the following postharvest attributes were evaluated: fruit number, diameter and weight, yield, pH, content of soluble solids, titratable acidity, contents of phenolic compounds and anthocyanins, and activity of peroxidase. Vegetative development of blueberry plants in response to Si presented higher yield, leaf area, phenylalanine ammonia lyase activity, and higher chlorophyll fluorescence relationships such as maximum photochemical efficiency and PSII potential activity, as well as less stressed plants, especially in cultivars Climax and Brightwell. For post-harvest physicochemical characteristics, silicon foliar application improved fruit weight and diameter for cvs. Beckblue and Climax, and fruit number for cv. Brightwell. All cultivars, in response to silicon application increased the titratable acidity, the levels of phenolic compounds, the level of anthocyanins, whereas peroxidase activity decreased. The performance of the evaluated blueberry cultivars was better through silicon application, with greater performance of vegetative growth, fruit yield, and fruit quality, especially in cultivar Climax, which was the most suitable in terms in of fruit yield in this study.The objective of this study was to evaluate the effect of foliar application of silicon in different blueberry (Vaccinium myrtillus) cultivars. The treatments were installed in a factorial design with six replications, and consisted of three different cultivars (Brightwell, Beckblue and Climax) with or without regular application of silicon via foliar, using silicon oxide at 1.5 g L-1. It was evaluated the following plant attributes: leaf area, chlorophyll fluorescence, and phenylalanine ammonia lyase activity, meanwhile the following postharvest attributes were evaluated: fruit number, diameter and weight, yield, pH, content of soluble solids, titratable acidity, contents of phenolic compounds and anthocyanins, and activity of peroxidase. Vegetative development of blueberry plants in response to Si presented higher yield, leaf area, phenylalanine ammonia lyase activity, and higher chlorophyll fluorescence relationships such as maximum photochemical efficiency and PSII potential activity, as well as less stressed plants, especially in cultivars Climax and Brightwell. For post-harvest physicochemical characteristics, silicon foliar application improved fruit weight and diameter for cvs. Beckblue and Climax, and fruit number for cv. Brightwell. All cultivars, in response to silicon application increased the titratable acidity, the levels of phenolic compounds, the level of anthocyanins, whereas peroxidase activity decreased. The performance of the evaluated blueberry cultivars was better through silicon application, with greater performance of vegetative growth, fruit yield, and fruit quality, especially in cultivar Climax, which was the most suitable in terms in of fruit yield in this study
Organic fertilizer doses for top-dressing fertilization in jambu (Acmella oleracea [(L.) R. K. Jansen]) production
Get PDFDue to the lack of specific fertilization recommendations for jambu cultivation, producers commonly usefertilizers recommended for other vegetables. This study aimed to evaluate the effect of different doses oforganic fertilizers, namely hoof and horn powder and castor bean cake, on jambu plant production under anorganic system. The experiments were conducted at the Experimental Farm of São Manuel, SP, belonging to theSchool of Agriculture (FCA) – UNESP, and at the “Estância Três Nascentes” site, located in Botucatu, SP, Brazil.Twelve treatments were evaluated, in a 2 x 6 factorial design, consisting of two organic fertilizers (castor beancake (CBC) and hoof and horn powder (HHP)) x 6 top dressing N doses (50, 75, 100, 125, 150, and 0 (controlwithout these fertilizers)). The experimental design was a randomized block with four replications. Plant height(PH), number of inflorescences (NI), the fresh weight of inflorescence (FWI), the fresh weight of vegetative parts(FWVP), and the total fresh weight (TFW) were evaluated at each location. Linear increases were observed in allcharacteristics in both locations as the fertilizer doses increased. Comparing the highest dose (150 kg ha-1 of N)with the control, increases of 109%, 251%, 218%, 283%, and 227% were obtained at the farm in São Manuel, and69%, 79%, 111%, 276%, and 118% in Botucatu, for PH, NI, FWVP, FWI, and TFW, respectively. When comparing thetwo fertilizers, HHP presented better results than CBC for most characteristics in both areas.Due to the lack of specific fertilization recommendations for jambu cultivation, producers commonly usefertilizers recommended for other vegetables. This study aimed to evaluate the effect of different doses oforganic fertilizers, namely hoof and horn powder and castor bean cake, on jambu plant production under anorganic system. The experiments were conducted at the Experimental Farm of São Manuel, SP, belonging to theSchool of Agriculture (FCA) – UNESP, and at the “Estância Três Nascentes” site, located in Botucatu, SP, Brazil.Twelve treatments were evaluated, in a 2 x 6 factorial design, consisting of two organic fertilizers (castor beancake (CBC) and hoof and horn powder (HHP)) x 6 top dressing N doses (50, 75, 100, 125, 150, and 0 (controlwithout these fertilizers)). The experimental design was a randomized block with four replications. Plant height(PH), number of inflorescences (NI), the fresh weight of inflorescence (FWI), the fresh weight of vegetative parts(FWVP), and the total fresh weight (TFW) were evaluated at each location. Linear increases were observed in allcharacteristics in both locations as the fertilizer doses increased. Comparing the highest dose (150 kg ha-1 of N)with the control, increases of 109%, 251%, 218%, 283%, and 227% were obtained at the farm in São Manuel, and69%, 79%, 111%, 276%, and 118% in Botucatu, for PH, NI, FWVP, FWI, and TFW, respectively. When comparing thetwo fertilizers, HHP presented better results than CBC for most characteristics in both areas