Tesio F.,ValOryza Sas 55 |
Follis F.,ValOryza Sas 55 |
Andres A.,Embrapa Temperate Agriculture
Experimental Agriculture | Year: 2014
Cultivation of less productive soils such as closed landfills has become convenient because European subsidies covered part of the risk to obtain production. Aim of the research was to evaluate grain yields of maize hybrids belonging to different maturity classes (FAO 200, 300 and 400) (Gretzmacher, R. (1979). Die Bodenkultur 30:256 - 280) grown on closed landfills by the adoption of two minimum tillage methods (chisel plowing at 0.35 m plus disk harrowing at 0.20 m, or only disk harrowing at 0.20 m). Maize cultivation inserted in a winter cereal rotation had a grain production ranging from 4.6 t ha-1 (FAO 200, disk harrowing only) to 8.3 t ha-1 (FAO class 400, chisel plowing plus disk harrowing) in the two considered years (2011 and 2012). The adoption of chisel plowing coupled with disk harrowing reduced yield fluctuation between years, and furnished higher yield performance if compared with the single disk harrowing passage. The best growing hybrid cycles were those belonging to FAO class 300 with production similar to that of the longest maturity class, and with moisture content equal to the shortest maturity class. Copyright © Cambridge University Press 2013.
Blanco C.C.,Federal University of Rio Grande do Sul |
Scheiter S.,Biodiversitat und Klima Forschungszentrum LOEWE BiK F |
Sosinski E.,Embrapa Temperate Agriculture |
Fidelis A.,Claro |
And 2 more authors.
Ecological Modelling | Year: 2014
Vegetation changes, such as shrub encroachment and forest expansion over grasslands, prairies and savannas have been related to changes in climatic (mainly rainfall and temperature) and atmospheric conditions (CO2 concentration). However, a longstanding question in ecology is how mosaics of forests and open-canopy ecosystems could persist over millennia in sites where climatic conditions favor forests. Here we tested the influence of interactions between grass-tree competition, environmental heterogeneity (topography), seed dispersal, initial density and spatial aggregation of vegetation patches and disturbance behavior (fire) on the long-term coexistence of forests and grasslands in South Brazil. For this, we incorporated the adaptive dynamic global vegetation model (aDGVM) into a spatially explicit modeling approach (2D-aDGVM). Our results showed that recurrent disturbance related to grasses such as fires plays a key role in maintaining the long-term coexistence of forests and grasslands, mainly through feedbacks between disturbance frequency and grass biomass. Topographic heterogeneity affected the rate of forest expansion by adding spatio-temporal variability in vegetation-fire feedbacks. However, the spatial pattern and connectivity of fire-prone (grasslands) and fire-sensitive (forest) vegetation patches were more important to maintain the long-term coexistence of both alternative vegetation states than the initial proportion of forest and grasslands patches. The model is the first individual-based DGVM to consider the combined effects of topography, seed dispersal and fire spread behavior in a spatially explicit approach. © 2014 Elsevier B.V.
Andres A.,Embrapa Temperate Agriculture |
Andres A.,University of Turin |
Concenco G.,Embrapa Western Region Agriculture |
Theisen G.,Embrapa Temperate Agriculture |
And 2 more authors.
Experimental Agriculture | Year: 2012
The weedy variety of Oryza sativa occurs in several rice cultivation areas reducing both grain yield and quality. Prevention and crop rotation are considered the basic means to reduce its presence. Weed control in sorghum is generally attained with atrazine. In this study, the efficacy of both chemical and mechanical methods for control, under different soil tillage conditions, of weedy rice and barnyardgrass during sorghum cultivation was evaluated with the aim to reduce the application rate of atrazine. In the case of chemical control, the atrazine rate (1000, 1500, 2000, 2500 and 3000 ga.i. ha-1) and application timing (pre-and post-emergence) were assessed. With the mechanical control method, the number of interventions (inter-row hoeing with sorghum at 3, 4-5 and 6-8 leaves) to avoid weed competition was determined. The effect of the tillage system on weed population was investigated comparing conventional (ploughing), minimum-tillage (disc harrowing) and sod seeding (no-tillage) in combination with pre-and post-emergence herbicide treatments. The results showed that efficient control of weedy rice and barnyardgrass was achieved in lowlands with sorghum in rotation with rice. Both chemical and mechanical methods of weed control in sorghum gave a level of efficiency higher than 60%. The application of atrazine was more efficient in pre-emergence application, rather than in post-emergence treatments, in all soil tillage systems tested. On both weed species, the most suitable application rate was the pre-emergence treatment with 1500 ga.i. ha-1, and the adoption of higher rates did not significantly increase the herbicidal efficacy. The adoption of two or three mechanical interventions resulted in sorghum yield higher than the chemical post-emergence application, and similar to the application of atrazine in pre-emergence. Higher yield results were in accordance to greater weed control, being obtained in the conventional tillage system. © 2012 Cambridge University Press.
Impacts of mixed farms on water quality of pinhal river sub-basin, Santa Catarina, Brazil [Impacto de sistemas de produção pecuários/agrícolas na qualidade da água da sub bacia do rio pinhal, Santa Catarina, Brasil]
Palhares J.C.P.,Embrapa Cattle Southest |
Guidoni A.L.,Embrapa Temperate Agriculture |
Steinmetz R.L.R.,Embrapa Swine and Poultry |
Mulinari M.R.,Embrapa Swine and Poultry |
Sigua G.C.,U.S. Department of Agriculture
Archivos de Zootecnia | Year: 2012
Brazil is one of the largest producers of food in the world. Agriculture and livestock production are concentrated in certain regions of the country. Livestock has been perceived as a constant threat to the quantity and quality of water resources. The objective of this study was to evaluate the impact of mixed farms on superficial water quality in Pinhal River sub-basin, which is located in Concordia, Santa Catarina State. Eight sampling sites representing different land-uses (LU1: dairy cattle; LU2: without animals; LU3: dairy + pigs + poultry + crops; LU4: pigs + poultry + crops; LU5: dairy + pigs + poultry + crops + human; LU6: dairy + pigs + crops; LU7 and LU8: dairy + pigs) were evaluated. These sampling sites were assessed longitudinally and sampled during the summer, spring, autumn, and winter of 2006 to 2009. LU1 presented the worst water quality with high concentrations of total suspended solids (TSS) and chemical oxygen demand. In this point, cows had access to the river. The highest concentration of nitrate (NO3-N) was found at the estuary of the river. There were higher concentrations of TSS, NO3-N and NO2-N in wet season. At this time, intensive fertilizer application to corn fields is common. Autumn and winter presented the worst water quality with respect to nitrogen concentration. Results showed a strong relationship between the sources of pollution (e.g., cows, pigs and poultries) and water quality. Managing the use of animal manure with optimum chemical fertilizer applications along with riparian fencing may provide important mitigation options for protecting water quality of Pinhal River.
Messias R.S.,Embrapa Temperate Agriculture |
Galli V.,Embrapa Temperate Agriculture |
Galli V.,Federal University of Rio Grande do Sul |
e Silva S.D.A.,Embrapa Temperate Agriculture |
Rombaldi C.V.,Federal University of Pelotas
Nutrients | Year: 2014
Plant carotenoids have been implicated in preventing several age-related diseases, and they also provide vitamin A precursors; therefore, increasing the content of carotenoids in maize grains is of great interest. It is not well understood, however, how the carotenoid biosynthetic pathway is regulated. Fortunately, the maize germplasm exhibits a high degree of genetic diversity that can be exploited for this purpose. Here, the accumulation of carotenoids and the expression of genes from carotenoid metabolic and catabolic pathways were investigated in several maize landraces. The carotenoid content in grains varied from 10.03, in the white variety MC5, to 61.50 μg·g-1, in the yellow-to-orange variety MC3, and the major carotenoids detected were lutein and zeaxanthin. PSY1 (phythoene synthase) expression showed a positive correlation with the total carotenoid content. Additionally, the PSY1 and HYD3 (ferredoxin-dependent di-iron monooxygenase) expression levels were positively correlated with β-cryptoxanthin and zeaxanthin, while CYP97C (cytochrome P450-type monooxygenase) expression did not correlate with any of the carotenoids. In contrast, ZmCCD1 (carotenoid dioxygenase) was more highly expressed at the beginning of grain development, as well as in the white variety, and its expression was inversely correlated with the accumulation of several carotenoids, suggesting that CCD1 is also an important enzyme to be considered when attempting to improve the carotenoid content in maize. The MC27 and MC1 varieties showed the highest HYD3/CYP97C ratios, suggesting that they are promising candidates for increasing the zeaxanthin content; in contrast, MC14 and MC7 showed low HYD3/CYP97C, suggesting that they may be useful in biofortification efforts aimed at promoting the accumulation of provitamin A. The results of this study demonstrate the use of maize germplasm to provide insight into the regulation of genes involved in the carotenoid pathway, which would thus better enable us to select promising varieties for biofortification efforts. © 2014 by the authors; licensee MDPI, Basel, Switzerland.
Neitzke R.S.,Embrapa Temperate Agriculture |
Jaksch T.,Weihenstephan-Triesdorf University of Applied Sciences |
Kohlrausch F.,Weihenstephan-Triesdorf University of Applied Sciences |
Rober R.,Weihenstephan-Triesdorf University of Applied Sciences
Acta Horticulturae | Year: 2013
Ornamental peppers are easy to propagate and cultivate. They have a relatively short production cycle and are well accepted by the market. This study aims to evaluate the response of 10 cultivars of ornamental peppers to different fertilization regimes. The experiment was conducted during the autumn season of 2010 in Freising, Germany. The plants were grown in 9 cm pots filled with substrate (commercial peatclay mix; ~80:20 vol.) and fertilized with a fertigation system based on subirrigation using a commercial fertilizer. The pots were placed in a greenhouse and treated during two phases, the first of 5 weeks and the second of 6 weeks, with different concentrations of a nutrient solution. Low fertilization leads to compact plants and high amounts of fertilizer result in large plants. But their ornamental value, determined by the number of the fruits, increases with rising fertilization.
Nascimento J.B.,Federal University of Goais |
Barrigossi J.A.F.,Embrapa Rice and Beans |
Borba T.C.D.O.,Embrapa Rice and Beans |
Martins J.F.D.S.,Embrapa Temperate Agriculture |
And 2 more authors.
Crop Protection | Year: 2015
This study aimed to observe the response of 34 rice accessions to attack by sugarcane borer (. Diatraea saccharalis Fabr., 1794) and to analyze the genetic diversity of these accessions by microsatellite markers. Twenty larvae were placed on the leaf sheaths of rice plants. At 30 days after infestation the rice plants at ground level were taken to the laboratory where the signs of borer attack, external and internal diameter of the stem and weight of surviving larvae were determined. For the molecular analysis of rice accessions, 24 microsatellite markers were used. The results of the morphological traits of the rice plant, response of the plant to insect attack, development of the sugarcane borer larvae and molecular data, indicated a genotypic variation. The accessions that most favored larval survival were IAC 47 and Ti Ho Hung. Larvae with highest weight (0.0986g and 0.0862g) and the largest internal diameters of the rice stem (3.18mm) were found in land races "Canela de Ferro" (rust colored stem) and all these "Canela de Ferro" accessions also remained genetically grouped. The most tolerant materials, based on the ability to produce new tillers after larval infestation were, Chiang an Tsao Pai Ku and IR 40 which remained morphological and genetically grouped. The results of this study indicate that all the traits and molecular analyses were able to separate the accessions of rice into different groups in relation to resistance to the sugarcane borer. These materials can be used as donor sources in breeding for genetic resistance to sugarcane borers and can be used as donors to amplify the genetic base of Brazilian rice. © 2014 Elsevier Ltd.
Reis D.A.,Federal University of Pelotas |
de Lima C.L.R.,Federal University of Pelotas |
Pauletto E.A.,Federal University of Pelotas |
Dupont P.B.,Federal University of Pelotas |
Pillon C.N.,Embrapa Temperate Agriculture
Scientia Agricola | Year: 2014
Management systems may influence the structural quality of soils. Tensile strength (TS) and friability (F) are indicators of soil structural quality. The aim of this study was to evaluate the TS and F of an Alfisol under different management systems. The treatments were as follows: (i) soil under conventional system with growing maize after tobacco cultivation, (ii) soil under conventional system with growing maize after use as pasture, (iii) soil under natural pasture, and (iv) a natural area with predominance of spontaneous vegetation. TS and F were evaluated at depths of 0.00-0.05 and 0.05-0.10 m. The water content of soil aggregates, soil particle-size distribution, total organic carbon, carbon in the coarse fraction and carbon associated with minerals were also determined. The increase in clay content and soil organic carbon influences the values of TS. The lowest TS was for the soil under maize cultivation after tobacco in the conventional system. Soil under natural area in the 0.05-0.10 m layer was classified as slightly friable, while other systems were classified as friable. Evaluations of the structural quality of soils under management systems can be performed using TS. However, F was not efficient in detecting changes between the different management systems.
Theisen G.,Embrapa Temperate Agriculture |
Theisen G.,Wageningen University |
Bastiaans L.,Wageningen University
Weed Research | Year: 2015
Germination is a key process in the dynamics of weed populations. In no-tillage systems, crop seeding is often found to induce seed germination in the seeding strip. In this research, experiments to investigate options for reducing weed seedling establishment were conducted in no-till soyabean fields located in two sites in south Brazil. A first experiment revealed that a reduction in emergence of some important weed species can be achieved by lowering seeding speed. Further experiments showed the ability of a modified seeder to contribute to an additional reduction in weed establishment. On the modified seeder, coulter discs were equipped with lateral blades, to diminish soil disturbance and to maintain a uniform soil cover by properly cutting the mulch layer. In a field with a high level of residues, the modified seeder, in contrast to the standard seeder, prevented the increase of soil exposure when seeding at high speed. The predominant weeds were annual species. Averaged over all seeding rates, the new equipment led to a 56% reduction in within-row weed density, compared with the standard seeder. Regardless of seeder type, overall weed density increased with seeding speed, but with the modified seeder, this increase was only half that of the standard seeder. The modified seeder reduced weed biomass by 30% and increased soyabean grain yield by 42%. The research demonstrated that relatively simple changes, like a minor modification to a seeder and a lower seeding speed, can contribute to more diverse and sustainable alternatives to predominantly chemical-oriented weed management strategies. Weed Research © 2015 European Weed Research Society.
Mayer N.A.,Embrapa Temperate Agriculture |
Ueno B.,Embrapa Temperate Agriculture |
Reighard G.L.,Clemson University
Acta Horticulturae | Year: 2015
Since the late 1970s several peach orchards in Rio Grande do Sul State, Brazil, have been affected by Peach Tree Short Life (PTSL). It is well documented that rootstocks are associated with the syndrome. Several Prunus genotypes are being studied at Embrapa Temperate Agriculture as rootstocks for PTSL tolerance for Southern Brazil. Prunus mume has been reported as resistant to Agrobacterium tumefaciens, Meloidogyne javanica and M. incognita, and shows some tolerance to drought. In this trial, four peach cultivars were budded on 550 Prunus mume seedlings and planted in a field with PTSL history. In 2012, 49 trees were selected and the following variables were registered: trunk diameter (TD), trunk cross-sectional area (TCSA), fruit number/tree before thinning (FNBT) and at harvest time (FNHT), yield/tree (Y), fruit set (FSE) and yield efficiency (YE), fruit weight (FW), longitudinal (LFD) and transversal fruit diameter (TFD), soluble solids content (SSC) and firmness (F). No PTSL symptoms were observed on peach/P. mume trees in the first three years after planting. Several differences related to tree development, yield, yield efficiency and fruit quality were observed among plants on the 49 selected P. mume seedlings. The genotypes CPACTUME- 03, CPACT-UME-04, CPACT-UME-05, CPACT-UME-11, CPACT-UME-13, CPACT-UME-26, CPACT-UME-46 and CPACT-UME-47 stood out in 2012. © 2015 ISHS.