Science, Brazil


Science, Brazil
Time filter
Source Type

Petry R.,UDESC CAV | Fonseca M.E.N.,Embrapa Vegetable Crops CNPH | Boiteux L.S.,Embrapa Vegetable Crops CNPH | Reis A.,Embrapa Vegetable Crops CNPH
Plant Disease | Year: 2017

Snap-bean is a main vegetable crop in small-scale agricultural systems in Brazil. In 2012, pods displaying water soaked lesions with white mold followed by pod decay and rotting were observed (∼5% incidence) in surveys of open-field grown crops in a commercial vegetable-producing sector in Brazlândia-DF, Brazil. Six isolates were obtained using 10% clarified V8 medium amended with 30 mg/liter of rifampicin. Analyses under light microscopy revealed coenocytic hyphae; papillated and pyriform sporangia with long pedicels. The sporangia (n = 50) were 47.8 μm (33 to 56 μm) × 30.3 μm (24 to 41 μm); oogonia were 37.3 μm (32 to 44 μm), and antheridia were 14.2 × 13.1 μm. Chlamydospores were not observed. These characteristics were in agreement with P. capsici description. All isolates were able to grow on V8 medium at 35°C, which discriminated them from P. tropicalis (Aragaki and Uchida 2001). The snap-bean isolates were paired with P. capsici A1 and A2 mating type testers in V8 medium. All isolates produced oospores only with the A2 isolates. In pathogenicity assays, intact pods were sprayed with monosporangium-derived suspensions (2 × 104 zoospores/ml) until run-off. Isolates induced similar symptoms on pods 4 days after inoculation and P. capsici was reisolated from these pods. All isolates induced crown rot after inoculation (2 × 104 zoospores/ml) of snap-bean ‘Fortuna’ (50% incidence) and Capsicum annuum ‘Ikeda’ (100% incidence) seedlings, whereas C. annuum ‘CM 334’ displayed no symptoms (Reifschneider et al. 1992). All isolates showed similar phenotypic attributes, thus only two isolates (PCva-01 and PCva-02) were selected for sequencing of the internal transcribed spacer (ITS) region. Total DNA was extracted from pure colonies using a modified CTAB method (Boiteux et al. 1999) and used as template in PCR assays with the ITS-1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS-4 (5′-TCCTCCGCTTATTGATATGC-3′) primer pair (White et al. 1990). BLASTn alignments of the PCva-01 (GenBank accession no. KT818615) and PCva-02 (KT818616) amplicon sequences (∼750 bp) showed 100% identity, and they shared 99 to 100% identity with a subset of publically available P. capsici ITS sequences (n > 100), including isolates described on P. vulgaris (GU011684) and P. lunatus L. (DQ464043). This combination of data allowed us to classify the snap-bean isolates as P. capsici. This pathogen has been reported infecting snap-bean pods elsewhere (Gevens et al. 2008). However, to our knowledge, this is the first record of P. capsici naturally infecting this crop in Brazil. Soil infested with P. capsici is the most likely initial source of inoculum. Susceptible crops such as squashes (C. moschata) and bell peppers are often cultivated in this area. The confirmation of snap-bean as an alternative host of P. capsici is an important information for establishing effective disease management strategies. © 2017, American Phytopathological Society. All rights reserved.

Da Silva S.C.,University of Sao Paulo | Gimenes F.M.A.,Institute Zootecnia | Sarmento D.O.L.,Uniao Pioneira de Integracao Social | Sbrissia A.F.,UDESC CAV | And 3 more authors.
Journal of Agricultural Science | Year: 2013

The ability to adapt to a range of edaphic conditions favours the widespread use of marandu palisade grass in high as well as low input systems of animal production in Brazil. However, little information exists regarding the influence of grazing management practices on sward structure and the carry-over effects on animal responses. The present experiment was planned to evaluate animal behaviour, herbage intake (HI) and nutritive value, herbage accumulation and body weight gain (BWG) of beef cattle heifers grazing marandu palisade grass subjected to intensities of continuous stocking management. Treatments corresponded to four sward surface heights (SSH: 100, 200, 300 and 400 mm) and were allocated to experimental units (1200 m2 paddocks) according to a randomized complete block design with four replications. Herbage accumulation rate (HAR) varied with season of the year and SSH, with highest and lowest values recorded during summer and winter, respectively. During the summer, herbage accumulation was larger on swards managed at 200, 300 and 400 mm, with the opposite occurring during winter/early spring. Stocking rate (SR) and number of grazing days (GD) followed a similar seasonal pattern of variation, with values decreasing as SSH increased. Crude protein (CP) and in vitro organic matter digestibility (IVOMD) of hand-plucked herbage decreased as SSH increased from 100 to 400 mm, while the inverse happened with BWG (from 0·190 to 0·930 kg/day, respectively). Bite mass (BM) increased and rate of biting and grazing time (GT) decreased as SSH increased, with daily HI being larger on tall (300 and 400 mm) relative to short (100 and 200 mm) swards. Grazing management affected the nutritive value and the amount of herbage consumed, particularly through changes in BM. However, variations in intake were relatively more important than variations in nutritive value in influencing animal performance, highlighting the importance of providing favourable harvest conditions for grazing animals by establishing adequate sward targets for management. © Cambridge University Press 2012.

Schoninger E.L.,UDESC CAV | Schoninger E.L.,University of Sao Paulo | Gatiboni L.C.,UDESC CAV | Ernani P.R.,UDESC CAV
Scientia Agricola | Year: 2012

Plants have shown different responses to fertilization with rock phosphate, including responses through alteration of the attributes of rhizospheric soil. The objective of this study was to evaluate soil pH alterations and alterations in the contents of forms of phosphorus in the rhizosphere of soil fertilized with rock phosphate as a result of cultivation of species of plants. An experiment was developed under greenhouse conditions to evaluate alterations in the pH and in the forms of phosphorus in the rhizosphere of an Oxisol fertilized with rock phosphate and cultivated with four species. Treatments consisted of the cultivation of four species of soybean - Glycine max (L.) Merrill, brachiaria grass - Brachiaria brizantha Hochst Stapf, millet - Pennisetum glaucum (L.) R. Brown, and sorghum - Sorghum bicolor (L.) Moench grown in PVC columns filled with soil and divided with a nylon screen (25 μm mesh) to impede root growth in part of the column. After 45 days of cultivation, the soil was divided into the layers of 0-1, 1-2, 2-3, 3-4, 4-5, 5-7, 7-9, and 9-14 mm from the rhizoplane and air dried to determine pH and P contents through Hedley fractionation. In the 1-2 and 2-3 mm layers, soybean cultivation caused an increase in pH when compared to the control treatment (without plants). In the other layers, there were no alterations in pH due to cultivation of plants. The cultivation of millet, brachiaria grass, and sorghum reduced the inorganic P content in the most labile forms only in the 0-1 mm layer from the rhizoplane.

Knoblauch R.,Epagri. Rod. Antonio Heil | Ernani P.R.,Santa Catarina State University | Gatiboni L.C.,Santa Catarina State University | Walker T.W.,Mississippi State University | And 3 more authors.
Revista Brasileira de Ciencia do Solo | Year: 2014

Incorporation of rice straw into the soil just before flooding for water-seeded rice can immobilize mineral nitrogen (N) and lead to the production of acetic acid harmful to the rice seedlings, which negatively affects grain yield. This study aimed to evaluate the formation of organic acids and variation in pH and to quantify the mineral N concentration in the soil as a function of different times of incorporation of rice straw or of ashes from burning the straw before flooding. The experiment was carried out in a greenhouse using an Inceptisol (Typic Haplaquept) soil. The treatments were as follows: control (no straw or ash); incorporation of ashes from previous straw burning; rice straw incorporated to drained soil 60 days before flooding; straw incorporated 30 days before flooding; straw incorporated 15 days before flooding and straw incorporated on the day of flooding. Experimental units were plastic buckets with 6.0 kg of soil. The buckets remained flooded throughout the trial period without rice plants. Soil samples were collected every seven days, beginning one day before flooding until the 13th week of flooding for determination of mineral N- ammonium (NH4 +) and nitrate (NO3 -). Soil solution pH and concentration of organic acids (acetic, propionic and butyric) were determined. All NO3 - there was before flooding was lost in approximately two weeks of flooding, in all treatments. There was sigmoidal behavior for NH4 + formation in all treatments, i.e., ammonium ion concentration began to rise shortly after soil flooding, slightly decreased and then went up again. On the 91stday of flooding, the NH4 + concentrations in soil was 56 mg kg-1 in the control treatment, 72 mg kg-1for the 60-day treatment, 73 mg kg-1for the 30-day treatment and 53 mg kg-1for the ash incorporation treatment. These ammonium concentrations correspond to 84, 108, 110 and 80 kg ha-1of N-NH4 +, respectively. When the straw was incorporated on the day of flooding or 15 days before, the concentration of N-NH4 + in the soil was 28 and 54 mg kg-1, equivalent to an accumulation of 42 and 81 kg ha-1 of N-NH4 +, respectively. There was formation of acetic acid in which toxic concentrations were reached (7.2 mmol L-1) on the 15th day of flooding only for the treatment with straw incorporated on the day of flooding. The pH of the soil solution of all the treatments increased after flooding and this increase was faster in the treatments with incorporation of straw, followed by the ash treatment and then the control. After 60 days of flooding, however, the pH values were around 6.5 for all treatments, except for the control, which reached a pH of 6.3. Rice straw should be incorporated into the soil at least 30 days before flooding; otherwise, it may immobilize part of the mineral N and produce acetic acid in concentrations toxic to rice seedlings.

Zanini G.D.,UDESC CAV | Santos G.T.,UDESC CAV | Sbrissia A.F.,Santa Catarina State University
Revista Brasileira de Zootecnia | Year: 2012

The objective of this study was to assess the accumulation and morphological composition of forage in Aruana Guineagrass (Panicum maximum cv. Aruana) swards subjected to intermittent stocking with sheep. Experimental treatments when grazing was introduced included low (95%) and high (98%) incident light interception and low (10 cm)- and high (15 cm)-residue height and were allocated to experimental units (196 m2 fenced areas) in a completely randomized 2 × 2 factorial arrangement with three replicates. Treatments were imposed between January and May 2009. More frequent grazing cycles (95% light interception) resulted in better control of stem elongation, lower proportion of dead plant material and invasive plants, and higher proportions of leaf blades in the grazing strata, compared with less frequent grazing cycles (98% light interception). Grass managed with 95% light interception combined with 10 and 15 cm post-grazing height and grass managed at 98% light interception combined with 15 cm post-grazing height did not show differences in forage accumulation rate. These results indicate that more frequent (30 cm pre-grazing height) and less severe (15 cm post-grazing height) grazing cycles provided animals with high leaf blade mass and low stem mass forage. © 2012 Sociedade Brasileira de Zootecnia.

Bertol I.,Santa Catarina State University | Ramos R.R.,UDESC CAV | Barbosa F.T.,University of La Coruña | Ramos J.C.,UDESC CAV | Bandeira D.H.,UDESC CAV
Revista Brasileira de Ciencia do Solo | Year: 2013

Water erosion is the major cause of soil and water losses and the main factor of degradation of agricultural areas. The objective of this work was to quantify pluvial water erosion from an untilled soil with crop rows along the contour, in 2009 and 2010, on a Humic Dystrupept, with the following treatments: a) maize monoculture; b) soybean monoculture; c) common bean monoculture; d) intercropped maize and bean, exposed to four simulated rainfall tests of on hour at controlled intensity (64 mm h-1). The first test was applied 18 days after sowing and the others; 39, 75 and 120 days after the first test. The crop type influenced soil loss through water erosion in the simulated rainfall tests 3 and 4; soybean was most effective in erosion control in test 3, however, in test 4, maize was more effective. Water loss was influenced by the crop type in test 3 only, where maize and soybean were equally effective, with less runoff than from the other crops. The soil loss rate varied during the runoff sampling period in different ways, demonstrating a positive linear relationship between soil and water loss, in the different rainfall tests.

da Costa A.,Federal University of Santa Maria | Albuquerque J.A.,Santa Catarina State University | da Costa A.,UDESC CAV | Pertile P.,UDESC CAV | da Silva F.R.,UDESC CAV
Revista Brasileira de Ciencia do Solo | Year: 2013

The retention and availability of water in the soil vary according to the soil characteristics and determine plant growth. Thus, the aim of this study was to evaluate water retention and availability in the soils of the State of Santa Catarina, Brazil, according to the textural class, soil class and lithology. The surface and subsurface horizons of 44 profiles were sampled in different regions of the State and different cover crops to determine field capacity, permanent wilting point, available water content, particle size, and organic matter content. Water retention and availability between the horizons were compared in a mixed model, considering the textural classes, the soil classes and lithology as fixed factors and profiles as random factors. It may be concluded that water retention is greater in silty or clayey soils and that the organic matter content is higher, especially in Humic Cambisols, Nitisols and Ferralsol developed from igneous or sedimentary rocks. Water availability is greater in loam-textured soils, with high organic matter content, especially in soils of humic character. It is lower in the sandy texture class, especially in Arenosols formed from recent alluvial deposits or in gravelly soils derived from granite. The greater water availability in the surface horizons, with more organic matter than in the subsurface layers, illustrates the importance of organic matter for water retention and availability.

This work was carried out to investigate the effect maturity stage at harvest (M1, M2 and M3, corresponding to fruit with 20-25%, 45-50% and 70-75% of peel red color surface, respectively) of 'Camila' and 'Laetitia' plums, and then stored in conventional cold storage, on ripening and quality, especially regarding the incidence of flesh browning. Fruits were cold stored during 40 days (1±0.1 °C and 95±2% RH), followed by three days at ambient condition (23±5 °C and 60±5% RH). 'Camila' plums harvested at maturity stage M1 showed the poorest evolution of peel red color during cold storage. Only fruit harvested at stage M3 had a good flesh red color development. The values of flesh firmness and force for fruit compression were different between maturity stages, being higher in M1 than in M2 and M3. On the other hand, fruit harvested at stage M1 had the highest force for flesh penetration. However, 'Camila' plums harvested with up to 50% of peel red color did not ripe satisfactory and had poor quality. 'Laetitia' plums showed satisfactory evolution of peel red color during cold storage, especially when harvested at stage M3. For this cultivar, the force for fruit compression was different between maturity stages, in the following order: M1>M2>M3. Titratable acidity was highest in fruit harvested at stage M1, while ethylene production rate was highest for fruit harvested at stage M3. 'Laetitia' plums harvested at the three maturity stages had similar ripening during cold storage. However, fruits should not be harvested with 20-25% of peel red color since they will have a high intensity of flesh browning during cold storage.

Modolon T.A.,UDESC CAV | Boff P.,Laboratory Homeopatia e Saude Vegetal | Boff M.I.C.,UDESC CAV | Miquelluti D.J.,UDESC CAV
Horticultura Brasileira | Year: 2012

Tomato crops (Solanum lycopersicum) under conventional production system are constantly treated against pest and diseases, with organic synthetic pesticides that are used may cause serious disturbance to environment and human health. This research was carried out in order to study the effect of homeopathic and high dilution preparations on pests and diseases management of tomato crop under organic production system. Two experiments were conducted under field conditions and one in greenhouse. All of them in randomized block design with the cultivar Santa Cruz Kada. The treatments consisted of homeopathic preparations Staphysagria, Arsenicum album, Sulphur, Arnica montana, high dilution preparations of Solanum lycopersicum and Solanum aculeatissimum, at the decimal (DH) or centesimal (CH) scale of hahnemanian high dilution. Bordeaux mixture, cupric preparation, and Bacillus thuringiensis were also included in weight doses. The preparation Arnica montana 12DH increased the tomato yield under field conditions. The damage incidence of small borer was efficiently reduced with applications of Sulphur 12CH that equalling to B. thuringiensis. The same treatment did not reduce the large borers. B. thuringiensis reduced also the septoria leaf spot incidence in the field. In greenhouse, the high dilution preparation of tomato at 12DH completely suppressed the septoria leaf spot and drastically reduced the same disease at 24DH. The homeopathic and high dilution preparations have the potential to be effective on replacing pesticides that are used on tomato, and could be suitable to fill legal requirement for organic production system.

Dalbo M.A.,Epagri Estacao Experimental de Videira | Bettoni J.C.,UDESC CAV | Gardin J.P.P.,Epagri Estacao Experimental de Videira | Basso C.,Epagri Estacao Experimental de Cacador
Revista Brasileira de Fruticultura | Year: 2015

Grapevine ‘Isabel’ grafted on rootstock ‘SO4’ and ‘IAC 766’ and planted on ungrafted Nitosol were treated annually with increasing concentrations of K2O, 0; 60; 120 and 180 kg ha-1 for 5 wine-growing seasons (2007/08 , 2008/09 , 2009/10 , 2010/11 and 2011/12). The experimental design was banded with five replications, with six plants per replication and the treatments in a 4×3 factorial design, with 12 treatments, corresponding to four doses of potassium fertilization and the three rootstocks. The stage of berries peel color change, stems were collected to determine the nutrient content in the grape leaves. At the time of harvest it was evaluated vegetative and productive behavior, such as productivity, weight pruning, Ravaz index, and analytical characteristics of berries, total soluble solids, titratable acidity and pH were evaluated. Increased potassium fertilization does not represent a gain in productivity in cv. Isabel nor the accumulation of soluble solids in grapes. K and Mg in petioles of grapes are influenced by the form of cultivation ( grafted or ungrafted ).’Isabel’ vines grown on ungrafted have less capacity to accumulation of K and higher of Mg in the petioles. Under the conditions of the soil that was developed the research is not justified potassium fertilization of the vineyard. © 2015, Sociedade Brasileira de Fruticultura. All rights reserved.

Loading UDESC CAV collaborators
Loading UDESC CAV collaborators