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Métodos de aplicação de peróxido de hidrogênio em mudas de gravioleira irrigadas com água salina
No full textThe acclimatization of plants to salt stress, through the application of hydrogen peroxide, occurs due to the activation of the antioxidant defense system. In this sense, the aim of the study was to evaluate the levels of photosynthetic pigments and the photochemical efficiency of soursop seedlings under irrigation with saline water and different methods of applying hydrogen peroxide. The study was carried out in greenhouse conditions, in a 5 x 4 scheme, with five levels of electrical conductivity of irrigation water - CEa (0.6; 1.2; 1.8; 2.4 and 3.0 dS m-1) and four methods of application of hydrogen peroxide-MA (without application of H2O2, application via seed soaking, application via leaf spray and application via seed soaking and leaf spray). The salinity of irrigation water up to 1.4 and 1.1 dS m-1 caused an increase in the synthesis of chlorophyll b and carotenoids, respectively. Irrigation with water from 0.6 dS m-1 reduced the synthesis of chlorophyll a and total of soursop plants. The application of 20 μm of H2O2 via seed imbibition results in an increase in the contents of chlorophyll a and b, total, maximum and variable fluorescence of soursop seedlings. Soaking the seeds with hydrogen peroxide increased the initial fluorescence of chlorophyll in plants irrigated with water 1.2 dS m-1.A aclimatação das plantas ao estresse salino, por meio de aplicação de peróxido de hidrogênio, ocorre devido à ativação do sistema de defesa antioxidante. Neste sentido, objetivou-se com o estudo avaliar os teores de pigmentos fotossintéticos e a eficiência fotoquímica de mudas de gravioleira sob irrigação com águas salinas e distintos métodos de aplicação de peróxido de hidrogênio. O estudo foi realizado em condições de casa de vegetação, em esquema 5 x 4, sendo cinco níveis de condutividade elétrica da água de irrigação – CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1) e quatro métodos de aplicação de peróxido de hidrogênio- MA (sem aplicação de H2O2, aplicação via embebição das sementes, aplicação via pulverização foliar e aplicação via embebição das sementes e pulverização foliar). A salinidade da água de irrigação até 1,4 e 1,1 dS m-1provocou aumento na síntese de clorofila b e carotenoides, respectivamente. Já a irrigação com água a partir de 0,6 dS m-1 reduziu a síntese de clorofila a e total das plantas de gravioleira. A aplicação de 20 μm de H2O2via embebição da semente resulta em aumento nos teores de clorofila a e b, total, fluorescência máxima e variável das mudas de gravioleira.A embebição das sementes com peróxido de hidrogênio aumentou a fluorescência inicial da clorofila nas plantas irrigadas com água de 1,2 dS m-1.
 
Antibiotic resistance profile of local thermophilic Bacillus licheniformis isolated from Maysan province soil
Get PDFThe key concern for public health is that bacterial strains isolated from various ecosystems are immune to antibiotics used in human medicine, thus dramatically limiting therapeutic options and threatening the lives of infected people. The present study aims to reveal the antibiotics profile of fiftysix isolates of local thermophilic Bacillus licheniformis isolated from different environmental soil sites in Maysan city, Iraq. The antimicrobial agent resistance profile of B. licheniformis isolates was performed using the disc diffusion assay according to Kirby-Bauer susceptibility test protocol. The results showed that isolates were resistance against cefepime (n=56; 100%), amoxicillin (n=13; 23.3%) and ampicillin (n=52; 92.9%); and intermediate (n=56; 100%) against cephalothin and naldixic acid. The percentage resistance was low for aztreonam (n=4; 7%), chloramphenicol (n=3; 5%), clotrimazole (n=6; 10%), novobiocin (n=2; 3.5%) and ticarcillin (n=3; 5%). On the other hand, all isolates were sensitive (n=56; 100%) towards the following antibiotics: amikacin, ceftazidime, ciprofloxacin, clindamycin, imipenem, netilmycin, gentamicin, nitrofurantion, rifampin, trimethoprim and vancomycin. The results of this study suggest that the Iraqi thermophilic B. licheniformis isolates are variable in their susceptibility towards the standards antimicrobial agents. Furthermore, the presence of cefepime, amoxicillin, ampicillin, cephalothin and naldixic resistant isolates of B. licheniformis in Iraqi soils is of concern about how resistance could spread to other bacteria, and ultimately to humans.The key concern for public health is that bacterial strains isolated from various ecosystems are immune to antibiotics used in human medicine, thus dramatically limiting therapeutic options and threatening the lives of infected people. The present study aims to reveal the antibiotics profile of fiftysix isolates of local thermophilic Bacillus licheniformis isolated from different environmental soil sites in Maysan city, Iraq. The antimicrobial agent resistance profile of B. licheniformis isolates was performed using the disc diffusion assay according to Kirby-Bauer susceptibility test protocol. The results showed that isolates were resistance against cefepime (n=56; 100%), amoxicillin (n=13; 23.3%) and ampicillin (n=52; 92.9%); and intermediate (n=56; 100%) against cephalothin and naldixic acid. The percentage resistance was low for aztreonam (n=4; 7%), chloramphenicol (n=3; 5%), clotrimazole (n=6; 10%), novobiocin (n=2; 3.5%) and ticarcillin (n=3; 5%). On the other hand, all isolates were sensitive (n=56; 100%) towards the following antibiotics: amikacin, ceftazidime, ciprofloxacin, clindamycin, imipenem, netilmycin, gentamicin, nitrofurantion, rifampin, trimethoprim and vancomycin. The results of this study suggest that the Iraqi thermophilic B. licheniformis isolates are variable in their susceptibility towards the standards antimicrobial agents. Furthermore, the presence of cefepime, amoxicillin, ampicillin, cephalothin and naldixic resistant isolates of B. licheniformis in Iraqi soils is of concern about how resistance could spread to other bacteria, and ultimately to humans
Response of citrus hybrids to Alternaria alternata inoculation
Get PDFCitrus orchards have some limitations, such as the occurrence of phytosanitary problems. Alternaria brown spot (ABS) is caused by fungus Alternaria alternata, which affects several parts of the plant by producing a host-specific toxin, known as ACT. ABS is a limiting factor in orchards due to the susceptibility of most planted cultivars: ‘Murcott’ tangor and ‘Ponkan’ tangerine. The selection of varieties resistant/tolerant to the disease has economic importance. Therefore, the aim of this experiment was to evaluate the response to A. alternata inoculation in a population of ‘Murcott’ tangor vs ‘Pera’ sweet orange hybrids. Leaves of 2-3 centimeters in length of ‘Murcott’ tangor, ‘Pera’ sweet orange, ‘Ponkan’, ‘Dancy’, ‘Fremont’ tangerine and 198 hybrids were collected. For in vitro inoculation, monosporic A. alternata culture at concentration of 105 conidia mL-1 was used. Inoculated leaves were stored in humid chamber. After 24, 48 and 72 hours of inoculation, leaf lesions were evaluated following a diagrammatic scale. The results obtained showed that most hybrids from the crossing of ‘Murcott’ tangor vs ‘Pera’ sweet orange are susceptible to ABS. However, 44 are resistant and ten are tolerant. Among ABS-tolerant hybrids, some have phenotype similar to that of cultivated and commercialized hybrids.Citrus orchards have some limitations, such as the occurrence of phytosanitary problems. Alternaria brown spot (ABS) is caused by fungus Alternaria alternata, which affects several parts of the plant by producing a host-specific toxin, known as ACT. ABS is a limiting factor in orchards due to the susceptibility of most planted cultivars: ‘Murcott’ tangor and ‘Ponkan’ tangerine. The selection of varieties resistant/tolerant to the disease has economic importance. Therefore, the aim of this experiment was to evaluate the response to A. alternata inoculation in a population of ‘Murcott’ tangor vs ‘Pera’ sweet orange hybrids. Leaves of 2-3 centimeters in length of ‘Murcott’ tangor, ‘Pera’ sweet orange, ‘Ponkan’, ‘Dancy’, ‘Fremont’ tangerine and 198 hybrids were collected. For in vitro inoculation, monosporic A. alternata culture at concentration of 105 conidia mL-1 was used. Inoculated leaves were stored in humid chamber. After 24, 48 and 72 hours of inoculation, leaf lesions were evaluated following a diagrammatic scale. The results obtained showed that most hybrids from the crossing of ‘Murcott’ tangor vs ‘Pera’ sweet orange are susceptible to ABS. However, 44 are resistant and ten are tolerant. Among ABS-tolerant hybrids, some have phenotype similar to that of cultivated and commercialized hybrids
Bell pepper yield as a function of an alternative source of organic matter
Get PDFFor a good development and a consequently high production, the bell pepper requires, among other conditions, satisfactory levels of soil fertility. In this perspective, this work aimed to evaluate the parameters of production and productivity of the bell pepper cultivar ‘Casca Dura Ikeda’ cultivated in field conditions, with different doses of buriti stem, in Bom Jesus, Piauí. The experiment was conducted at the Horticulture Department of the Campus Professora Cinobelina Elvas of the Federal University of Piauí (CPCE/UFPI). The experimental design was in randomized blocks with treatments distributed in plots referring to organic fertilization. There were five (5) doses of buriti stem (0, 10, 20, 30, and 40 t ha-1) plus an additional treatment (bovine manure and NPK mineral fertilizer), with four replications and an experimental unit consisting of twenty plants. The following variables were analyzed: number of fruits per plant, mean fruit length, basal diameter, mean thickness of the fruit pulp, mean fruit weight, production, and yield. We concluded that the yield attributes of the bell pepper cv. ‘Casca Dura Ikeda’ are influenced by organic fertilization, and production is increased by the buriti stem doses of 20 t ha-1 and 30 t ha-1 and by the use of the combination of manure and mineral fertilizer.For a good development and a consequently high production, the bell pepper requires, among other conditions, satisfactory levels of soil fertility. In this perspective, this work aimed to evaluate the parameters of production and productivity of the bell pepper cultivar ‘Casca Dura Ikeda’ cultivated in field conditions, with different doses of buriti stem, in Bom Jesus, Piauí. The experiment was conducted at the Horticulture Department of the Campus Professora Cinobelina Elvas of the Federal University of Piauí (CPCE/UFPI). The experimental design was in randomized blocks with treatments distributed in plots referring to organic fertilization. There were five (5) doses of buriti stem (0, 10, 20, 30, and 40 t ha-1) plus an additional treatment (bovine manure and NPK mineral fertilizer), with four replications and an experimental unit consisting of twenty plants. The following variables were analyzed: number of fruits per plant, mean fruit length, basal diameter, mean thickness of the fruit pulp, mean fruit weight, production, and yield. We concluded that the yield attributes of the bell pepper cv. ‘Casca Dura Ikeda’ are influenced by organic fertilization, and production is increased by the buriti stem doses of 20 t ha-1 and 30 t ha-1 and by the use of the combination of manure and mineral fertilizer
Foliar application of biofertilizer in semi-hydroponic lettuce fertigated with saline nutrient solution
Get PDFWater scarcity in the world is a problem diagnosed especially in countries with large semi-arid regions such as Brazil. Research has been conducted with a view to making use of saline waters as an input for cultivation, particularly in hydroponics, with especial focus on lettuce, the most prominent leafy vegetable in Brazil. The objective of this study was to evaluate the development of lettuce in a semi-hydroponic system fertigated with saline water and under foliar fertilization with biofertilizer. The present study was carried out in a greenhouse located in the experimental area of the Department of Environmental and Technological Sciences (DCAT) of the Federal Rural University of the Semi-Arid Region, in the municipality of Mossoró, RN, Brazil. The experimental design was a randomized complete block design, with treatments arranged in a 2 x 4 factorial scheme, with 4 replicates, two salinity levels of the water used to prepare the nutrient solution (0.5 and 3.5 dS m-1) and four biofertilizer concentrations (0, 20, 40 and 60%) applied by foliar spraying. The evaluated characteristics were: shoot diameter, stem diameter, number of leaves, fresh mass, dry mass, leaf succulence, leaf area and specific leaf area. The use of saline water to prepare the nutrient solution reduces fresh mass and dry mass production in the lettuce crop. The biofertilizer can be applied through the leaves at concentration of up to 20%, promoting greater plant growth.Water scarcity in the world is a problem diagnosed especially in countries with large semi-arid regions such as Brazil. Research has been conducted with a view to making use of saline waters as an input for cultivation, particularly in hydroponics, with especial focus on lettuce, the most prominent leafy vegetable in Brazil. The objective of this study was to evaluate the development of lettuce in a semi-hydroponic system fertigated with saline water and under foliar fertilization with biofertilizer. The present study was carried out in a greenhouse located in the experimental area of the Department of Environmental and Technological Sciences (DCAT) of the Federal Rural University of the Semi-Arid Region, in the municipality of Mossoró, RN, Brazil. The experimental design was a randomized complete block design, with treatments arranged in a 2 x 4 factorial scheme, with 4 replicates, two salinity levels of the water used to prepare the nutrient solution (0.5 and 3.5 dS m-1) and four biofertilizer concentrations (0, 20, 40 and 60%) applied by foliar spraying. The evaluated characteristics were: shoot diameter, stem diameter, number of leaves, fresh mass, dry mass, leaf succulence, leaf area and specific leaf area. The use of saline water to prepare the nutrient solution reduces fresh mass and dry mass production in the lettuce crop. The biofertilizer can be applied through the leaves at concentration of up to 20%, promoting greater plant growth
Production of Formosa papaya seedlings irrigated with wastewater and application of biostimulant
Get PDFPapaya (Carica papaya L.) is one of the leading fruit trees in Brazil, mainly in the Northeast region. However, some regions suffer from water scarcity, making wastewater reuse a viable alternative for crop production. Also, biostimulants may be used to maximize papaya growth and development. Thus, this work aimed to evaluate the use of Acadian® biostimulant in the growth of Formosa papaya seedlings irrigated with different concentrations of fish-farming wastewater. The experiment was block randomized in a 2 x 5 factorial scheme, use and non-use of biostimulant and five concentrations of wastewater (0, 10, 20, 30, and 40%) diluted in potable water, with four replicates. Qualitative data were compared by t-test at 5% probability, and quantitative data were submitted to regression analysis. Results showed that high concentrations of wastewater negatively affect the production of Formosa papaya seedlings. Acadian® negatively influences plant height, number of leaves, and the ratio between shoot and root. However, the seaweed biostimulant positively influenced the chlorophyll content index.Papaya (Carica papaya L.) is one of the leading fruit trees in Brazil, mainly in the Northeast region. However, some regions suffer from water scarcity, making wastewater reuse a viable alternative for crop production. Also, biostimulants may be used to maximize papaya growth and development. Thus, this work aimed to evaluate the use of Acadian® biostimulant in the growth of Formosa papaya seedlings irrigated with different concentrations of fish-farming wastewater. The experiment was block randomized in a 2 x 5 factorial scheme, use and non-use of biostimulant and five concentrations of wastewater (0, 10, 20, 30, and 40%) diluted in potable water, with four replicates. Qualitative data were compared by t-test at 5% probability, and quantitative data were submitted to regression analysis. Results showed that high concentrations of wastewater negatively affect the production of Formosa papaya seedlings. Acadian® negatively influences plant height, number of leaves, and the ratio between shoot and root. However, the seaweed biostimulant positively influenced the chlorophyll content index
Post-harvest storage of ‘Paluma’ guavas produced by plants fertirrigated with nitrogen and biofertilizer
Get PDFThe association between mineral fertilizer and biofertilizers can contribute to guavas quality. An experiment was carried out in order to assess, over the days, \u27Paluma\u27 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 \u27Paluma\u27 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 \u27Paluma\u27 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, \u27Paluma\u27 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 \u27Paluma\u27 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 \u27Paluma\u27 guava
Saline water and nitrogen doses in the cultivation of West Indian cherry in the post-grafting phase
Get PDFThis study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters.This study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters
Sulfur doses, organic compost and gypsum in macronutrients contents of collard greens leaves
Get PDFDue to the lack of information related to fertilization of collard greens, the objective of the research was to evaluate the influence of sulfur doses in macronutrients contents in collard greens cultivated with organic compost and gypsum. Twelve treatments were evaluated in a split-plot: three types of soil preparation in plots and four sulfur doses top dressing in subplots. The three types of soil preparation were the incorporation of organic compost (30 t ha-1); gypsum (1.2 t ha-1); organic compost (30 t ha-1) plus gypsum (1.2 t ha-1). The total sulfur doses in top dressing were zero; 53.32; 106.68 and 160.00 kg ha-1 of S, equivalent to 0; 266; 532 and 800.0 kg ha-1of ammonium sulfate. For standardization of the nitrogen dose (280 kg∙ha-1), applied in top dressing it was used urea. From the dry matter of commercial leaves, it was evaluated the N, P, K, Ca, Mg and S contents. The types of soil preparation do not affect all macronutrients content. The sulfur top dressing applied does not alter the contents of leaf macronutrients N, P, K and Ca on collard greens cultivated with organic compost and gypsum. The sulfur content presents a linear increase, while for the magnesium content there is decrease the higher the sulfur doses. The decreasing order of macronutrient content of commercial collard greens leaves was K> N> Ca> Mg> S> P, with averages 37.92, 36.50, 21.69, 4.50, 4.23, 3.80 g kg-1, respectively.
Due to the lack of information related to fertilization of collard greens, the objective of the research was to evaluate the influence of sulfur doses in macronutrients contents in collard greens cultivated with organic compost and gypsum. Twelve treatments were evaluated in a split-plot: three types of soil preparation in plots and four sulfur doses top dressing in subplots. The three types of soil preparation were the incorporation of organic compost (30 t ha-1); gypsum (1.2 t ha-1); organic compost (30 t ha-1) plus gypsum (1.2 t ha-1). The total sulfur doses in top dressing were zero; 53.32; 106.68 and 160.00 kg ha-1 of S, equivalent to 0; 266; 532 and 800.0 kg ha-1of ammonium sulfate. For standardization of the nitrogen dose (280 kg∙ha-1), applied in top dressing it was used urea. From the dry matter of commercial leaves, it was evaluated the N, P, K, Ca, Mg and S contents. The types of soil preparation do not affect all macronutrients content. The sulfur top dressing applied does not alter the contents of leaf macronutrients N, P, K and Ca on collard greens cultivated with organic compost and gypsum. The sulfur content presents a linear increase, while for the magnesium content there is decrease the higher the sulfur doses. The decreasing order of macronutrient content of commercial collard greens leaves was K> N> Ca> Mg> S> P, with averages 37.92, 36.50, 21.69, 4.50, 4.23, 3.80 g kg-1, respectively
Could effective microorganisms improve tolerance of UCB1 pistachio to salinity?
Get PDFSalinity is one of the most important limiting factors for plant growth which can reduce its undesirable effects through stress modulators. In order to investigate the effect of effective microorganisms (EM) on morphological indices and activity of some enzymes in UCB1 rootstock pistachio under salinity stress, a factorial experiment was conducted as a randomized complete blocks design. Factors included were salinity stress at four levels (0.7, 5, 10 and 13.6 dS m-1) and EM at two levels (0, 1%) with three replications. Treatments were applied for three months on plants. The results showed that increasing salinity decreased seedling height, leaf number, stem and root fresh and dry weight, but the activity of (CAT), peroxidase (POD) and ascorbate peroxidase (AXP) enzymes increased compared to control treatment, whereas EM application showed that concentration of 1% of this fertilizer increased the measured morphological indices and decreased the activity of CAT, POD and AXP enzymes. Interaction effect between salinity and EM was significant only on morphological indices. According to the results, it can be stated that application of EM could reduce adverse effects of salinity stress on the UCB1 rootstock.Salinity is one of the most important limiting factors for plant growth which can reduce its undesirable effects through stress modulators. In order to investigate the effect of effective microorganisms (EM) on morphological indices and activity of some enzymes in UCB1 rootstock pistachio under salinity stress, a factorial experiment was conducted as a randomized complete blocks design. Factors included were salinity stress at four levels (0.7, 5, 10 and 13.6 dS m-1) and EM at two levels (0, 1%) with three replications. Treatments were applied for three months on plants. The results showed that increasing salinity decreased seedling height, leaf number, stem and root fresh and dry weight, but the activity of (CAT), peroxidase (POD) and ascorbate peroxidase (AXP) enzymes increased compared to control treatment, whereas EM application showed that concentration of 1% of this fertilizer increased the measured morphological indices and decreased the activity of CAT, POD and AXP enzymes. Interaction effect between salinity and EM was significant only on morphological indices. According to the results, it can be stated that application of EM could reduce adverse effects of salinity stress on the UCB1 rootstock