947 resultados para Citrus - Fungicides


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The objective of this study was to evaluate the performance and carcass traits of steers fed corn or citrus pulp associated with sunflower meal or urea. Diets were composed of two energy sources (corn grain and citrus pulp) associated with two protein sources (soybean meal and urea), resulting in four treatments in forage:concentrate ratio of 40:60. It were used 24 steers, 1/2 Angus × 1/2 Nellore (18 months old and 329 kg BW) distributed in a completely randomized design which were finished in feedlot for 80 days. It were evaluated the intake, average daily gain and carcass traits of the animals. Intake of dry matter (DMI), crude protein (CPI) and neutral detergent fiber (NDFI) were affected (p<0.05) by diets. The diet with citrus pulp and urea (PU) showed the lowest (p<0.05) DMI (8.30 kg), CPI (1.03 kg) and NDFI (3.31 kg). The average daily weight gain (ADG) followed the behavior of DMI, NDFI and CPI and the lowest value (p<0.05) was observed for animals fed diet PU. Regarding carcass traits, diets containing corn associated with urea (MU) or sunflower meal (MFG) and citrus pulp associated with sunflower meal (PFG), provided the highest (p<0.05) carcass cold weights (238.37, 247.26 and 237.14 kg, respectively). However, the lowest cold carcass dressing percentage (p<0.05) was obtained in diet MU (50.57%). The association of citrus pulp with urea should not be performed when citrus pulp partially or totally replace corn as energy source in diets, because possibly this association promote an energy deficit resulting in lower performance and worse carcass traits of animals finished in feedlot.

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Fungicide application is one of the control strategies of fungal diseases in corn leaves. In Brazil, there are no fungicides recorded for the control of corn macrospora leaf spot (MLS). The aim of this study was to assess the efficacy of 16 fungicides on MLS control in a protective, curative and eradicant form. Fungicides of the chemical groups of benzimidazoles, strobilurins and triazoles were used alone or in mixture, in completely randomized block design, with six replicates of five plants, totaling 30 plants per treatment. The experiments were carried out in a greenhouse with the single-cross hybrid AS 1565 in phenological stage of two to six expanded leaves, using an isolate of S. macrospsora from the same hybrid. The inoculum was deposited into the cartridge of plants at 48 hours after, 48 hours before and 10 days before fungicide applications for preventive, curative and eradicant action, respectively. The experiment was repeated twice. The data underwent analysis of variance (p<0.05), and the means of treatments were compared by using the Scott-Knott test (p<0.05). Severity was estimated at 21 days after inoculations. All fungicides significantly differed from the control treatment in the preventive, curative and eradicant action. For the preventive action, mean disease control was 85%. The mixture of triazoles plus strobilurins controlled, on average, 75% of the disease severity, while the isolated products such as strobilurins reduced it by 62%, benzimidazoles by 55% and triazoles by 38% for the curative action. The lowest control was obtained for the eradicant action, with mean reduction of 40.1% in the disease severity and no significant difference among fungicides.

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Monitoring the survival of nematophagous fungi is needed to establish periods of reapplication of formulations of nematophagous fungi to control the citrus nematode in the field. We monitored the survival of fungi: Arthrobotrys robusta, A. oligospora, A. musiformis Dactylella leptospora and Monacrosporium eudermatum in plots treated with 1, 2, 4, 6 liters of the formulation of fungi/plant or witness without the application, during the period of nine months with the first assessment six months after application and the other with intervals of three months after the first evaluation. The fungus D. leptospora was found only in the evaluation of 6 months after treatment application, indicated a short survival time in the soil. However, the isolated A. robusta, A. musiformis and A. oligospora were recovered in all evaluations and especially in plots treated with higher doses of the formulation and witness. Monacrosporium eudermatum was recovered in all experimental periods and even in assessing the witness portion of nine months after application. The fact of the presence of species of Arthrobotrys and M. eudermatum in control plots indicates that native species that were already orchard.

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The efficiency of monitoring fertigation by means of porous capsule extractors is directly related to its correct placement, since the nutrients applied through fertigation have different mobility throughout the soil profile. The objective of this study was to evaluate the distributions of NO3, P, and K in the soil solution, when applied in citrus in sandy soil through drip fertigation systems, aiming to define the proper placement of the solution extractors. In order to measure the concentration of ions in the soil solution, the extractors were installed at four different distances (5, 15, 25, and 35 cm) and depths (15, 30, 60, and 90 cm) with an emitter located under the projection of the tree canopy. The experiment was conducted in a Valencia orange orchard on citrumelo Swingle rootstock, in Reginópolis/SP. The experimental design was randomized blocks and the treatment arrangement was a 4 x 4 factorial design with five repetitions. Sixteen soil solution extractors were installed per block, with a total of 80 extractors in the experiment. According to the obtained results, to determine P and K, it is recommended to install the solution extractor at 15 cm horizontal and 30 cm depth from the emitter. For NO3, the extractor recommended placement is 25 cm horizontal and 30 cm depth. The soil solution extractor proved to be a sensitive tool, capable of determining the ions mobility in the wet bulb.

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The plant-pathogenic bacterium Xanthomonas citri subsp. citri is the causal agent of Asiatic citrus canker, a seriousdisease that affects all the cultivars of citrus in subtropical citrus-producing areas worldwide. There is no curative treatment for citrus canker; thus, the eradication of infected plants constitutes the only effective control of the spread ofX. citri subsp. citri. Since the eradication program in the state of São Paulo, Brazil, is under threat, there is a clear risk of X. citri subsp. citri becoming endemic in the main orange-producing area in the world. Here we evaluated the potential use of alkyl gallates to prevent X. citri subsp. citri growth. These esters displayed a potent anti-X. citri subsp. citri activity similar to that of kanamycin (positive control), as evaluated by the resazurin microtiter assay (REMA). Thetreatment of X. citri subsp. citri cells with these compounds induced altered cell morphology, and investigations of the possible intracellular targets using X. citri subsp. citri strains labeled for the septum and centromere pointed to a commontarget involved in chromosome segregation and cell division. Finally, the artificial inoculation of citrus with X. citri subsp. citri cells pretreated with alkyl gallates showed that the bacterium loses the ability to colonize its host, which indicates the potential of these esters to protect citrus plants against X. citri subsp. citri infection. © 2013, American Society for Microbiology.

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Gastric ulcer is an excoriated area of the gastric mucosa. It is among the predominant gastrointestinal chronic diseases. The essential oils represent an important part of the traditional pharmacopoeia in many countries and have been successfully used for gastroprotection and ulcer healing. Thus, this review presents the experimental activity of essential oils traditionally used in the gastric ulcer prevention and treatment, considering their families, part of the plant studied, bioassays, and their mechanisms of gastroprotection and ulcer healing, with the aim of stimulating novel studies in the search for a new phytomedicine to treat gastric diseases. © 2012 The Authors Fundamental and Clinical Pharmacology © 2012 Société Française de Pharmacologie et de Thérapeutique.

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The consumer market demands food without pesticide residues. Therefore, this study focused on evaluating the control of green mold in Pera orange trees with biocontrol agents (Bacillus subtilis, Bacillus licheniformis and Bacillus subtilis (QST 713)), associated or not with heat treatment. The fruit was obtained in packinghouse before processing, being washed and disinfected with the use of Sodium Hypochlorite. Fruits submitted to these treatments were stored from 11 to 28 days at temperature of 10 °C and RH 90%±5 or for eight days at 20 °C and 90%±5. In general, the heat treatment reduced the disease severity determine by the area under the disease progress curve in the fruit and the incidence of natural postharvest disease in Pera oranges. On the other hand, biocontrol agents did not control the disease, showing that the organisms tested did not present curative activity against the green mold.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Environmental problems caused by synthetic fungicides have increased the search for alternative methods of control of plant diseases. The objective was to evaluate the effect of essential oil of citronella grass, on the fungus Rhizoctonia solani, in different methods of in vitro fungitoxicity. We used a randomized design in a factorial design with four replications, where the factors were composed of four methods for assessing the in vitro fungitoxicity of the essential oil of citronella grass (essential oil diluted in Tween 80 (0.5%) and embedded in the culture medium PDA (potato dextrose agar) still melting, essential oil diluted in Tween 80 (0.5%) and distributed on the surface of the PDA; oil essential diluted in Tween 80 (0.5%) and distributed on filter paper attached to the inner surface of the lid of the Petri dish, pure essential oil and distributed on the surface of the culture medium, and control) and five evaluation periods (2, 4, 6, 8 and 10 days of incubation). Was used 0.25μL mL-1 of citronella oil in all treatments. Of the treatments evaluated the use of pure oil distributed on the surface of the culture medium was more effective in reducing the mycelial diameter in all evaluations. In this method the rate of mycelial growth was 9,02 mm day-1, reaching in last evaluation 79,77 mm.

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This work was carried out with the objective to evaluate the effect of different carbohydrate sources associated with sunflower oil on performance, carcass characteristics and cuts yields of feedlot sheep. Twenty four lambs were assigned to a completely randomized design with a 2 × 2 factorial arrangement with two sources of neutral detergent soluble carbohydrate, starch or neutral detergent soluble fiber, with and without the inclusion of 4.2% sunflower oil. The treatments consisted of diets containing high content of soluble fiber (17.14% DM) without adding oil, high in soluble fiber (16.35% DM) with inclusion of 4.2% sunflower oil, high starch (30.14% DM) without adding oil and high starch (28.21% DM) with addition of 4.2% of sunflower oil. The animals were feedlot with average initial of 17.7 kg and when reached 35 kg body weight were slaughtered. The different sources of carbohydrate and oil inclusion in the diet not influence the days on feedlot in the dry matter intake and average daily weight gain, but higher feed conversion was observed for the diet with a high percentage of neutral detergent soluble fiber compared to diet high in starch. The carcass weights and yields as well as the commercial cuts were not affected by diets. The performance and quantitative characteristics and carcass cuts of lamb are not affected by different carbohydrate sources and their association with 4.2% sunflower oil.

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Microsatellites, or simple sequence repeats (SSRs), have proven to be an important molecular marker in plant genetics and breeding research. The main strategies to obtain these markers can be through genomic DNA and from expressed sequence tags (ESTs) from mRNA/cDNA libraries. Genetic studies using microsatellite markers have increased rapidly because they can be highly polymorphic, codominant markers and they show heterozygous conserved sequences. Here, we describe a methodology to obtain microsatellite using the enrichment library of DNA genomic sequences. This method is highly efficient to development microsatellite markers especially in plants that do not have available ESTs or genome databases. This methodology has been used to enrich SSR marker libraries in Citrus spp., an important tool to genotype germplasm, to select zygotic hybrids, and to saturate genetic maps in breeding programs. © Springer Science+Business Media, LLC 2013.

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Background: Citrus flavonoids, such as hesperidin, have shown therapeutic properties that improve hyperglycemia and insulin resistance, and decrease blood serum lipids and inflammation. The current investigation studied the effects of hesperidin supplementation associated with continuous and interval swimming on the biochemical parameters (glucose, cholesterol and triglycerides), and oxidative stress markers (TBARS and DPPH) in rats.Methods: The animals (n = 60) were randomly divided in six groups: negative (C) and positive control (CH) for hesperidin supplementation, and continuous or interval swimming without (CS and IS) or with hesperidin supplementation (CSH and ISH). Hesperidin was given by gavage for four weeks (100 mg/kg body mass) before the exercise. Continuous swimming was performed for 50 min with loads from 5% to 8 % of body weight from the first to fourth week, while interval swimming training was performed for 50 min in sessions of 1 min of swimming followed by 2 min of resting, carrying loads from 10% to 15, 20 and 25% from the first to fourth week. At the end of the experiment, blood serum samples were draw to perform analysis of glucose, total cholesterol, HDL-C and triglycerides. Oxidative biomarkers were evaluated by lipid peroxidation (TBARS) and antioxidant capacity assay (DPPH) of the blood serum.Results: There was a continuous decline of serum glucose from C (100%) > CH (97%) > CS (94%) > CSH (91%, p < .05), IS (87%, p < .05) > ISH (80%, p < .05), showing a combined beneficial effect of hesperidin and swimming. Also, continuous or intermittent swimming with hesperidin supplementation lowered total cholesterol (-16%, p < .05), LDL-C (-50%, p < 0.05) and triglycerides (-19%, p < 0.05), and increased HDL-C (48%, p < .05). Furthermore, hesperidin enhanced the antioxidant capacity on the continuous swimming group (183%, p < .05) and lowered the lipid peroxidation on the interval swimming group (-45%, p < .05).Conclusions: Hesperidin supplementation per se, or in combination with swimming exercise protocols, improved the biochemical profile and antioxidant biomarkers evidencing that the use of flavanones may enhance the health benefits promoted by exercise. © 2013 de Oliveira et al.; licensee BioMed Central Ltd.

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The aim of this study was to evaluate consumers' use and interpretation of ready to drink orange juice and nectar label information and its influence on the purchase decision. One hundred and sixty-seven consumers of ready to drink orange juice and nectar were interviewed. The labels were analysed to evaluate their conformance to Brazilian legislation. The manufacturing and shelf life date were the information most often checked, followed by health related issues. Brand, price and flavour were the most important factors for purchase decision. Brand and flavour showed significant association with consumer age. For most interviewed, 'nectar', 'whole' and 'natural' or '100% natural' were not well understood; they were not in accordance with the Brazilian legislation. 'Nectar', 'whole' and 'natural' or '100% natural' received a positive interpretation, whereas 'reconstituted juice' was considered a negative expression. Nevertheless, none of the labels completely conformed to the specific nutritional labelling legislation. © 2013 Institute of Food Science and Technology.

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The objective of this study was to evaluate different citrus leprosis management tactics during seven seasons, based in pruning and acaricide applications, considering technical and economic aspects of each tactic. The trial was conducted from October 2003 to August 2010 in an orange plantation of Pera cv. located in the municipality of Reginópolis-SP, Brazil. The plants of citrus used were12 years old and grafted onto Cleopatra tangerine. The experimental design used was randomized blocks, in a factorial scheme, made up of factors type of pruning (A), with six levels: (1) drastic pruning, (2) intermediate pruning without leprosis lesions, (3) intermediate pruning with leprosis lesions (4) light pruning, (5) without pruning and (6) replant; acaricide applications factor (B), with three levels: (1) without acaricides applications, (2) with lime sulfur applications and (3) spirodiclofen or cyhexatin applied in rotation; pruning factor to remove leprosis symptomatic branches (C), with two levels: (1) with pruning for removal, (2) without removal pruning. The combination of factors, with respective levels (6 x 3 x 2), resulted in 36 treatments that were repeated four times, with each parcel being made up of three plants in a row. After seven years, it was observed that the types of the pruning and remove of leprosis symptomatic branches used as single management tactic, is not sufficient to leprosis control. Therefore, the results demonstrated that for leprosis management, it is essential the association between tactics, especially the control mite vector. For ensuring the citrus production economically, the use of acaricides highly efficient is essential in B. phoenicis control. The recommendation of the type of pruning should be in function of the leprosis incidence and severity in the orchard. In orchards with low leprosis incidence and severity the light pruning is more appropriate, because it is efficient and ensures greater financial balance. However, in orchards with high leprosis incidence and severity it is indicated the severe pruning for reducing or eliminating inoculum source. Between the severe prunings, the intermediate pruning with leprosis lesions is the most relevant, because the financial return will be faster. Replant is indicated only for young orchards, because does not imply in changes onto cultural practices.

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The application of fungicides in the aerial organs is control strategy to macrospora spot caused by fungus Stenocarpella macrospora. The objective of this study was to determine the sensitivity of S. macrospora to fungicides by inhibition of mycelial growth (MG) and conidial germination (CG). It was eval uated 12 fungicides belonging to the chemical groups of the benzimidazoles, triazoles and strobilurins, six concentrations and two isolates of the fungus (SC and MT). The fungicides were diluted in sterile distilled water and added to the culture medium of potato dextrose agar (mycelium) and water-agar (spore) after sterilization. The percentage of inhibition of MC and CG was calculed in comparison with control, estimating of 50% inhibitory concentration (IC50). The fungicides tested were effective in inhibiting the MC. The IC50 was less than 1 ppm for all fungicides. There was no difference between isolates. The inhibition of CG had higher fungitoxicity strobilurins, and the IC50 was between 0.0035 and 0.03 ppm, and the isolated SC showed the higher sensitivity to the fungicides. The IC50 values obtained for fungicides and specific S. macrospora will be useful in monitoring the sensitivity of the fungus, especially in regions with intense demand for fungicides in corn.