Índices fisiológicos e clorofila em mangueira “Palmer” submetida a fontes de potássio

Grown in different regions of Brazil, mango is of great importance at the national level. However, mango cultivation is directly related to physiological factors such as photosynthesis, stomatal conductance and chlorophyll. Physiological factors are related to the nutritional balance of the plant. Among the nutrients, potassium (K) can be highlighted, which, despite not being a structural element for the plant, stimulates, or is part of several physiological plant processes. Therefore, an experiment was carried out with the purpose of evaluating, in the vegetative period of 'Palmer' mango, the effect of different sources of K to accelerate the maturation stage of mango branches and verify their influence on physiological indexes and chlorophyll. Treatments consisted of three ripeners and a control, which were applied directly to the branches and leaves of “Palmer” mango trees. The variables analyzed were chlorophyll A, B and Total indexes; Internal concentration of CO2; Stomatal conductance; transpiration rate; Net photosynthesis; Instantaneous Carboxylation Efficiency and Water Use Efficiency. After collecting, and analyzing the data, it was concluded that the vegetative period of the “Palmer” mango tree, in relation to the different evaluation dates, was not influenced by potassium sources. The use of T4 treatment (SpeedFol® induction mango) can provide a greater increment of chlorophyll A, B and Total than KCl and K2SO4.Cultivada em diferentes regiões do Brasil, a mangueira apresenta grande importância em nível nacional. Entretanto, o cultivo da mangueira está diretamente relacionado a fatores fisiológicos como fotossíntese, condutância estomática e clorofila. Os fatores fisiológicos estão relacionados ao equilíbrio nutricional da planta. Dentre os nutrientes, pode-se destacar o potássio (K), o qual, apesar de não ser um elemento estrutural para a planta, estimula ou faz parte de diversos processos fisiológicos no vegetal. Diante disso, foi realizado um experimento com a finalidade de avaliar, no período vegetativo da mangueira ‘Palmer’, a aplicação de diferentes fontes de K para acelerar o estágio de maturação dos ramos da mangueira e verificar sua influência sobre os índices fisiológicos e clorofila. Os tratamentos consistiam na avaliação de três maturadores e uma testemunha, que foram aplicados via foliar diretamente nos ramos e folhas da mangueira “Palmer”. As variáveis analisadas foram: índices de clorofila A (Chla), B (Chlb) e Total (Chlt); Concentração interna de CO2 (Ci); Condutância estomática (gs); Taxa transpiratória (E); Fotossíntese líquida (A); Eficiência instantânea da carboxilação (EiC) e Eficiência no uso da água (EUA). Após a coleta e análise dos dados, chegou-se à seguinte conclusão: no período vegetativo da mangueira “Palmer”, em relação às diferentes datas de avaliação, não houve influência entre as fontes de potássio. O uso do tratamento T4 (SpeedFol® manga indução) pode proporcionar maior incremento de clorofila A, B e Total do que KCl e K2SO4

Fruit production and quality of guava ‘Paluma’ as a function of humic substances and soil mulching

The uses of humic substances and organic residues for soil mulching have been more common during last years. This way, an experiment was carried out to evaluate the fruit quality and yield of guava cv. Paluma as a function of humic substances and organic soil mulching in Brazil. The experiment was performed from January 2012 to June 2013 (first trial) and from July to November 2013 (second trial) using a randomized blocks with treatments distributed in a factorial arrangement (5 × 2 × 2) of five humic substances doses (0, 10, 20, 30 and 40 mL of Humitec plant-1), two organic mulching use (with and without organic mulching) and two consecutive harvests, with four replications of two plants each. Humic substances enhance fruit production more efficiently in guava plants grown without soil mulching. Guava fruit production increases from the first to the second harvest. Fruit quality for titratable acidity, soluble solids, vitamin C and soluble solids/titratable acidity ratio is adequate independently of soil mulching use. Humic substances improve fruit quality of guava cv. Paluma. Under soil and climate conditions, and considering the first two production cycles of guava, it is possible to recommend about 20 mL L-1 of humic substances for production of high quality guava fruits.Key words: Humic acids, post-harvest, Psidium guajava

GROWTH AND WATER CONSUMPTION OF TWO BEAN SPECIES UNDER IRRIGATION WITH SALINE WATER

A salinidade é um importante problema ambiental, especialmente em regiões onde a irrigação com água de qualidade inferior é praticada. Neste sentido, um experimento foi conduzido entre maio e agosto de 2005 na Universidade Federal da Paraíba, Areia, Brasil com o objetivo de avaliar o crescimento e consumo de água das espécies Phaseolus vulgaris e Vigna unguiculata, irrigadas com diferentes níveis de salinidade. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 6 x 2 referentes à condutividade elétrica da água de irrigação (ECw), como segue: 0,0; 1,5; 3,0; 4,5; 6,0 e 7,5 dS m-1 e duas espécies de feijão, respectivamente, com quatro repetições e seis vasos por parcelas. O diâmetro do caule, matéria seca de raízes e parte aérea e consumo de água das plantas de feijoeiro foram avaliadas. Incementando-se o nível de salinidade da água da irrigação, os resultados de todas as variáveis decresceram drasticamente para ambas as espécies. P. vulgaris foi mais deleteriamente afetada pela salinidade da água que V. unguiculata.Salinity is an important environmental problem, specially in regions where irrigation with low quality water is practiced. In this sense, an experiment was carried out from May 2005 to August 2005 at Federal University of Paraiba, Areia, Brazil aiming to evaluate the growth and water consumption of Phaseolus vulgaris e Vigna unguiculata, irrigated with different salinity levels. The treatments were distributed in a completely randomized design, in factorial arrangement 6 x 2 referring to electrical conductivity levels of water irrigation (ECw), as follows: 0.0; 1.5; 3.0; 4.5; 6.0 e 7.5 dS m-1 and two bean species, respectively, with four repetitions and six pots in each parcel. The stem diameter, shoot and root dry mass and water consumption of bean plants were evaluated. Increasing water salinity level, the results of all variables decreased drastically for both species. Phaseolus vulgaris species is more deleteriously affected by water salinity than Vigna unguiculata

Post-harvest storage of ‘Paluma’ guavas produced by plants fertirrigated with nitrogen and biofertilizer

The association between mineral fertilizer and biofertilizers can contribute to guavas quality. An experiment was carried out in order to assess, over the days, 'Paluma' guavas physical-chemical quality in function of nitrogen fertilizer and biofertilizer doses. It was adopted a randomized blocks with treatments distributed in a factorial 5 x 2 x 5 referring to evaluation days post-harvest (0, 3, 6, 9 and 12), nitrogen fertilization (50 and 100% culture recommendation) and application of bovine biofertilizer doses by fertigation (0.0, 2.5, 5.0, 7.5 and 10.0%). The physical-chemical quality of 'Paluma' guava fruit was influenced by the association between liquid bovine biofertilizer and nitrogen fertilization. This combination increased soluble solids, titratable acidity, ratio, vitamin C, pH, firmness and loss of fresh mass, but did not affect the pulp percentage. The bovine biofertilizer, together with mineral fertilization, is important to increase the post-harvest quality of 'Paluma' guava.The association between mineral fertilizer and biofertilizers can contribute to guavas quality. An experiment was carried out in order to assess, over the days, 'Paluma' guavas physical-chemical quality in function of nitrogen fertilizer and biofertilizer doses. It was adopted a randomized blocks with treatments distributed in a factorial 5 x 2 x 5 referring to evaluation days post-harvest (0, 3, 6, 9 and 12), nitrogen fertilization (50 and 100% culture recommendation) and application of bovine biofertilizer doses by fertigation (0.0, 2.5, 5.0, 7.5 and 10.0%). The physical-chemical quality of 'Paluma' guava fruit was influenced by the association between liquid bovine biofertilizer and nitrogen fertilization. This combination increased soluble solids, titratable acidity, ratio, vitamin C, pH, firmness and loss of fresh mass, but did not affect the pulp percentage. The bovine biofertilizer, together with mineral fertilization, is important to increase the post-harvest quality of 'Paluma' guava

Reaproveitamento do resíduo da indústria de carnaúba no substrato para produção de mudas de melancia

Os produtores de mudas de hortaliças estão sempre ávidos por novas tecnologias, especialmente quando se trata do insumo substrato para plantas. Neste sentido, objetivou-se avaliar o desenvolvimento de mudas de melancia cultivar Crimson Sweet, produzidas em diferentes proporções de resíduo de carnaúba para composição de substratos. O experimento foi conduzido em delineamento experimental inteiramente casualizado com cinco tratamentos com diferentes proporções de resíduo de carnaúba com casca de arroz (RCCA) e resíduo de carnaúba em pó (RCP): 1) 100 % RCCA; 2) 75 % RCCA + 25 % RCP; 3) 50 % RCCA + 50 % RCP; 4) 25 % RCCA + 75 % RCP; e 5) 100 % RCP com quatro repetições de 64 plântulas cada. Há influência do uso resíduo de cera de carnaúba como componente de substrato na formação de mudas de melancia cv. Crimson Sweet. O substrato 100% RCCA pode ser usado na produção de mudas de melancia de qualidade

Micronutrientes foliares na goiabeira fertirrigada com biofertilizante e nitrogênio no semiárido

Required in small amounts, micronutrients play a key role for adequate plant development, which can be supplied by synthetic or organic fertilizers, such as biofertilizers. Thus, an experiment was conducted between July 2014 and August 2015, in the experimental area of the Federal University of the São Francisco Valley, Petrolina-PE, Brazil, to evaluate the micronutrient leaf concentrations of Paluma guava as a function of fertigation with bovine biofertilizer and Nitrogen fertilization. The experimental design was a randomized complete block design (5 x 2) referring to the concentrations of bovine biofertilizer (0, 2.5, 5.0, 7.5 and 10%) and N-fertilizing (50% and 100% of N dose following plant demand), with four replicates and five plants per plot. Only the leaf Mn concentrations are affected by bovine biofertilizer in guava trees fertigated with 100% of recommended N. Leaf concentrations of all the micronutrients (Mn, B, Fe and Zn) are not influenced by nitrogen fertigation. The biofertilizer is efficient in providing Fe.Demandados em pequenas quantidades, os micronutrientes exercem papel fundamental para o desenvolvimento adequado das plantas e podem ser fornecidos por insumos sintéticos ou orgânicos, como os biofertilizantes. Dessa forma, um experimento foi conduzido entre julho de 2014 e agosto de 2015, na área experimental da Universidade Federal do Vale do São Francisco, Petrolina-PE, para avaliar os teores foliares de micronutrientes em goiabeira Paluma em função de fertirrigação com biofertilizante bovino e adubação nitrogenada. O delineamento experimental foi em blocos casualizados em esquema fatorial (5 x 2) referentes às concentrações de biofertilizante bovino (0, 2,5, 5,0, 7,5 e 10%) e adubação mineral com nitrogênio (50% e 100% do recomendado segundo a demanda da cultura), com quatro repetições e cinco plantas por parcela. Apenas os teores foliares de Mn são afetados pelo biofertilizante bovino em goiabeiras fertirrigadas com 100% de N. Os teores foliares de todos os micronutrientes (Mn, B, Fe e Zn) não são influenciados pela fertirrigação nitrogenada. O biofertilizante é eficiente no fornecimento de Fe

BIOESTIMULANTE NA PRODUÇÃO DE MUDAS DE VIDEIRA CV. CRIMSON SEEDLESS

A produção de mudas com qualidade é fundamental na exploração das culturas agrícolas, e os bioestimulantes apresentam-se como ferramentas benéficas nessa fase da planta. O estudo objetivou avaliar as diferentes concentrações de bioestimulante composto por extrato de algas, no favorecimento da expansão radicular e desenvolvimento vegetativo inicial de mudas de uva, cultivar Crimson Seedless enxertadas em porta-enxerto SO4. O experimento foi realizado em viveiro comercial na cidade de Petrolina-PE. O delineamento experimental utilizado foi o inteiramente casualizado, com cinco tratamentos e quatro repetições. Os tratamentos foram: (T1) 0; (T2) 0,75; (T3) 1,12; (T4) 1,5 e (T5) 1,87 mL planta-1 do bioestimulante. Aos 45 dias após a enxertia foram analisados o comprimento e diâmetro da brotação do enxerto; área foliar; diâmetro, densidade, área, comprimento e matéria seca das raízes e matéria seca da parte aérea. Os dados foram submetidos à análise de variância e analise de regressão polinomial. Os melhores resultados foram proporcionados pela aplicação da dose 0,75 mL planta-1. O aumento da dose causou efeito fitotóxico. Conclui-se que o bioestimulante é uma ferramenta importante na produção de mudas com qualidade

Calcium fertilization strategy on mango physiological characteristics and yield

Calcium (Ca) is a nutrient responsible for maintaining plant quality and fruit yield. The production of new Ca sources, such as micronized (CaM) and complexed Ca (CaC), and their supplementation provide a better yield in mango cultivation. This study aimed to evaluate the effect of Ca sources (micronized and complexed with Ascophyllum nodosum) and application methods on mango cultivation, in semi-arid Brazil. The experimental design was randomized blocks, in a 6 x 6 factorial scheme. The Ca supplementation strategies (control; 1 L ha-1 of CaM; 2 L ha-1of CaM; 2 L ha-1 of CaC with A. nodosum extract; 2 L ha-1 of CaC with A. nodosum extract + application of 2.5 L ha-1 via CaC fertigation; and 2.5 L ha-1 via CaC fertigation) were evaluated on six dates regarding nutritional aspects. For biochemical and production aspects, the six supplementation strategies with Ca were evaluated. The Ca concentration in leaves and fruits significantly affected the interaction among the factors. The fertilization strategy with 2.5 L ha-1 of complexed calcium via fertigation was fundamental to provide increases in the nitrogen and Ca concentration of the fruits from 65 days after full flowering, and had positive effects on fruiting and production of mangoes cv. Kent

Sugar apple seedling production as a function of substrates and slow-release fertilizer

There is still a lack of studies on the effect of slow-release fertilizers and substrates on the production of high-quality sugar apple seedlings. In this context, the present study aimed to evaluate the quality and biomass of sugar apple seedlings grown in organic substrates at doses of slow-release fertilizer. The experimental design was randomized blocks in split-plot scheme, with four replicates and eleven plants per plot. Substrates were evaluated in the plots (fresh sugarcane bagasse; enriched sugarcane bagasse; coconut powder; commercial organic substrate Tropstrato®), whereas the doses of the slow-release fertilizer Osmocote® were evaluated in the subplots (0; 3; 6; 9; 12 and 15 kg m-3 of substrate). Substrates and slow-release fertilizer doses had effect on the formation of sugar apple seedlings. The effect of slow-release fertilizer is influenced by the substrate used in the formation of sugar apple seedlings. The substrate coconut powder showed the best performance for E%, NL and LAI in sugar apple plants, which reinforces its recommendation to be used in seedling production. For the studied conditions, based on the DQI, we recommend coconut powder associated with the slow-release fertilizer dose of 9 kg m-3 to produce sugar apple seedlings.There is still a lack of studies on the effect of slow-release fertilizers and substrates on the production of high-quality sugar apple seedlings. In this context, the present study aimed to evaluate the quality and biomass of sugar apple seedlings grown in organic substrates at doses of slow-release fertilizer. The experimental design was randomized blocks in split-plot scheme, with four replicates and eleven plants per plot. Substrates were evaluated in the plots (fresh sugarcane bagasse; enriched sugarcane bagasse; coconut powder; commercial organic substrate Tropstrato®), whereas the doses of the slow-release fertilizer Osmocote® were evaluated in the subplots (0; 3; 6; 9; 12 and 15 kg m-3 of substrate). Substrates and slow-release fertilizer doses had effect on the formation of sugar apple seedlings. The effect of slow-release fertilizer is influenced by the substrate used in the formation of sugar apple seedlings. The substrate coconut powder showed the best performance for E%, NL and LAI in sugar apple plants, which reinforces its recommendation to be used in seedling production. For the studied conditions, based on the DQI, we recommend coconut powder associated with the slow-release fertilizer dose of 9 kg m-3 to produce sugar apple seedlings

Fertilization strategies to reduce the formation of stenospermocarpic mango fruits in the semiarid region

Abstract The mango cultivation has shown considerable losses, due to the intense occurrence of physiological disorders in its fruits, and stenospermocarpy is the main disorder under tropical semiarid conditions. So, the experiment was carried out to evaluate the potential loss of yield of mango cv. Palmer by stenospermocarpy, its relation with the nutritional state of the plant and yield as a function of fertilization strategies. The study was conducted in two experimental areas in the Brazilian semiarid. There is evidence that the leaf contents of phosphorus (P), iron (Fe) and zinc (Zn) influenced the development of stenospermocarpy fruits, associated with high temperature and low relative humidity in the flowering period of the crop. The incidence of fruits affected by stenospermocarpy reaches 90%, with an estimated yield loss of 28.81 Mg ha-1 for the mango cv. Palmer