• Authors:
    • Maldaner, G. L.
    • Spera, S. T.
    • Fontaneli, R. S.
    • dos Santos, H. P.
  • Source: PESQUISA AGROPECUARIA BRASILEIRA
  • Volume: 46
  • Issue: 10
  • Year: 2011
  • Summary: The objective of this work was to assess energy conversion and balance of integrated crop-livestock production systems, under no-tillage. The experiment was carried out from 2001 to 2008. From 2001 to 2002, the following systems were evaluated: 1, wheat/soybean, and black oat pasture+common vetch/corn; 2, wheat/soybean, and black oat pasture+common vetch+ryegrass/corn; 3, wheat/soybean and black oat pasture+common vetch/millet pasture; 4, wheat/soybean and black oat pasture+common vetch+rygrass/millet pasture; 5, wheat/soybean, white oat/soybean, and black oat pasture+common vetch/millet pasture; 6, wheat/soybean, white oat/soybean, and black oat pasture+common vetch+rygrass/millet pasture. From 2003 to 2008, the following systems were evaluated: 1, wheat/soybean, and common vetch/corn; 2, wheat/soybean, and black oat pasture/corn; 3, wheat/soybean, and black oat pasture/soybean; 4, wheat/soybean, and field pea/corn; 5, wheat/soybean, common vetch/soybean, and double purpose triticale/soybean; and 6, wheat/soybean, double purpose white oat/soybean, and double purpose wheat/soybean. Corn showed highest returned energy in comparison to the other grain crops, and to winter and summer annual pastures. Of the winter cover crops and green manure species evaluated, field pea was the most efficient in energy conversion. Systems 1, 2, and 4, from 2003 to 2008, had the most efficient energy balance.
  • Authors:
    • Bueno, O. de C.
    • Frigo, E. P.
    • Frigo, M. S.
    • Esperancini, M. S. T.
    • Klar, A. E.
  • Source: Energia na Agricultura
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: The knowledge production and energy expenditure in agriculture is crucial due to strategic importance which occupies as a producer of energy inputs to other economic sectors, such as biodiesel produced from oilseed crops, so this study was attempt to determine the energy cost of partial deployment and conduct of corn intercropping agroecosystem with physic nut, under the steering and without irrigation, in an experiment conducted in accordance with the productive system of family farming in the west of Parana State. Such a study is justified due to the scarcity of energy data of the culture of physic nut under brazilian conditions, as well as in intercropping system under technological conditions of the family farm west of Parana, and especially environmental issues involved in this study as the rational use of energy sources nonrenewable. The experiment was conducted in accordance with the techniques employed by family farmers in western Parana, from February 2008 to May 2008 for corn and from February 2008 to November 2009 for the cultivation of physic nut in the Experimental Center of Agricultural Engineering (NEEA), belonging to the State University of Western Parana (UNIOESTE), campus of Cascavel/PR, in the area of tillage. The final product was assessed only corn. The technical coefficients, the workload, performance, identification of the tractor, implements and equipment, their specifications and their consumption of fuel, lubricants and greases, as well as quantification of manpower used were derived from primary data and secondary. The methodology consisted of determining the "Efficiency Cultural Partial" and "Energy Efficiency Partial". Regarding the energy balance in part, cultural and energy efficiency partial there were no major differences between the systems studied. We conclude that the conditions of the experiment the conduction system assessed in terms of energy both systems have the same performance.
  • Authors:
    • Carvalho, S. A. de
    • Setin, D. W.
  • Source: Citrus Research and Technology
  • Volume: 32
  • Issue: 1
  • Year: 2011
  • Summary: Citrus Sudden Death (CSD) a citrus disease of indeterminate causal agent, imposed changes to the Sao Paulo state citrus nursery tree production, with the substitution of the Rangpur lime for tolerant rootstocks as Swingle citrumelo, which, however, is less resistant to water deficit. The use of inarched nursery trees, combining resistance to water deficit and to CSD, can be interesting for planting in areas of risk, sparing the need of irrigation. The objective of this research was to evaluate different containers and grafting methods for the production of Valencia sweet orange nursery trees with double-rootstocks: Rangpur lime and Swingle citrumelo. Two containers (0.05 dm 3 and 0.25 dm 3 leaching tubes) and two grafting methods (inarching and spliced approach grafting) were evaluated for production of double-rootstocks. The comparison was performed against the single patterns (Rangpur lime or Swingle). Plant growth before and after grafting was evaluated in the final evaluation, the volume and mass of roots and mass of scion dry matter were measured. Single and double rootstocks grown initially in tubes of 0.25 dm 3, and Valencia nursery trees produced on the same container, demonstrated higher growth. Valencia nursery trees on Swingle citrumelo and Rangpur lime double rootstocks presented similar growth to trees grafted on Swingle citrumelo single rootstock. However, considering the potential of such type of nursery trees, its production may be held by sowing different rootstocks in the same tube of 0.25 dm 3, performing the graft by inarching method and the transference to bags where the canopy bud is grafted.
  • Authors:
    • Nascimento, J. J. V. R. do
    • Oliveira, G. dos S.
    • Silva, G. F. da
    • Pereira, R. G.
    • Paiva, M. R. de F. C.
  • Source: Revista Verde de Agroecologia e Desenvolvimento Sustentavel
  • Volume: 6
  • Issue: 2
  • Year: 2011
  • Summary: The planting of castor bean ( Ricinus communis L.) by seedlings can be an alternative for a better use of the short rainy season in the Brazilian semiarid, but in this region, irrigation water, almost always has a salt concentration that affects the quality of seedlings the vast majority of oil. In this context, this work was to study the effects of saline water at levels of 0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 dS m -1 and two volumes substrate: 1.0 and 2.5 L on the germination and early growth of two castor bean cultivars (BRS BRS Paraguacu and Northeast). The study was conducted in the open at the Experimental Station of Embrapa Cotton, in Barbalha, Ceara. Treatments were arranged in randomized blocks in five replicates, using the factorial 2*2*6. Regardless of cultivar, although the saline water inhibits germination and plant development, the effects were more pronounced in treatments with lower volume of substrate. Both cultivars have suffered more the action of salinity on growth during the initial seed germination.
  • Authors:
    • Stuchi, E. S.
    • Souza, M. C. de
    • Goes, A. de
  • Source: Crop Breeding and Applied Biotechnology
  • Volume: 11
  • Issue: 1
  • Year: 2011
  • Summary: A citrus scab disease, caused by Elsinoe fawcettii, is currently found in all citrus areas throughout Brazil. That being, given the importance of this casual agent, the behavior of tangerines and hybrids influenced by this pathogen was evaluated under natural infection conditions. This study was performed with plants around 15 years old without irrigation; 100 fruits of three plants were collected during harvest season, using a grade scale varying from 0 (absence of symptoms) to 6 (severe symptoms) the level of disease severity was determined. Among the cultivars, citrus scab resistance was observed in Citrus deliciosa, C. tangerina, C. nobilis; a mandarin hybrid ( C. nobilis * C. deliciosa) and a satsuma hybrid ( C. unshiu * C. sinensis). Among the other genotypes, symptoms were observed with levels of severity ranging from 1 to 3, indicating moderate resistance.
  • Authors:
    • Carvalho, D. F. de
    • Botrel, T. A.
    • Souza, W. J.
    • Silva, L. D. B. da
  • Source: Revista Brasileira de Engenharia Agrícola e Ambiental
  • Volume: 15
  • Issue: 8
  • Year: 2011
  • Summary: The use of localized irrigation using microtube as emitter under turbulent flow regime can be a technically feasible alternative. The objective of this study was to evaluate the performance of a fertigation system in nursery of citrus plants (greenhouse) projected by universal mathematical model, using the microtubes as emitters, under turbulent flow rate and to compare the development of the fertigated plants by microtubes to the system that use the traditional method with hoses. In the size of the length of the emitters was considered the K coefficient of localized energy dissipation using a microtube with internal diameter of 0,761 mm. The fertigation system presented great performance with clogging degree, Christiansen uniformity and emission uniformity values equal to 0,50; 99,95 and 98,21%, respectively, after 160 days of study. Plants that were grown using fertigation with both microtubes and hoses showed no difference as regards to stem diameter and height. Thus, the use of the microtube under turbulent flow rate presented technical feasible for fertigation system.
  • Authors:
    • Peluzio, J. M.
    • Almeida, R. D. de
    • Afférri, F. S.
  • Source: Revista Ciência Agronômica
  • Volume: 42
  • Issue: 1
  • Year: 2011
  • Summary: The aim of this work was to evaluate the genetic divergence among twelve soybean cultivars under irrigated lowland conditions in south Tocantins State, Brazil, in the Companhia Brasileira de Agropecuaria (COBRAPE), at Formoso do Araguaia, TO, in the inter-cropping 2005. The experimental design employed was randomized blocks with twelve treatments and tree replications. The treatments consisted on the following cultivars: DM Vitoria, MG/BR 46 (Conquista), Suprema, BRS Pintado, DM 247, BRS/MG 68, BRS/MG Lideranca, BRS MG Seguranca, DM 339, BRS/MG Garantia, A 7002, and DM 309. The following characteristics were evaluated: grain yield, weight of hundred seeds, number of seeds per pod, number of pods per plant, number of days for flowering; number of days for maturation, plant height and height insertion of the primary pod. Genetic divergence was evaluated by multivariate procedures: generalized Mahalanobis distance, Tocher's agglomerative method of Tocher and nearest neighbor. The Tocher's method and nearest neighbor agreed among themselves. Number of days for the maturation (39.49%), weigh of hundred seeds (26.56%) and number of days for flowering (13.59%) were the traits that most contributed to the genetic dissimilarity. The presence of genetic variability allowed the identification of dissimilar cultivars with high average for the traits studied. BRS/MG Garantia * DM 339 and BRS/MG Garantia * MG/BR 46 (Conquista) hybridizations are promising for obtaining segregate populations with higher variability.
  • Authors:
    • Costa Crusciol, C. A.
    • Calonego, J. C.
    • Amaral Castro, G. S.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 12
  • Year: 2011
  • Summary: The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha(-1) of dolomitic lime (ECC = 90%) or 4.1 Mg ha(-1) of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.
  • Authors:
    • Lima, N. R. C. de B.
    • Mendonca, F. C.
    • Santos, P. M.
    • Araujo, L. C. de
  • Source: Revista Brasileira de Zootecnia
  • Volume: 40
  • Issue: 7
  • Year: 2011
  • Summary: The objective of this work was to evaluate the development and productive traits of palisadegrass single cultivated or intercropped with corn, in addition to corn intercropped with pasture, under water deficit at different development stages of the plants. It was used a complete block experimental design with split plots and three replicates. Periods of water deficit were placed in the plots and types of cultivation were placed in the subplots. Irrigation was stopped at germination and initial tillering of palisadegrass and at V4 and V15 stages of corn and returned when soil moisture was 40% of available water capacity. Tiller density and palisadegrass height were evaluated weekly. Dry matter (DM) of fractions of herbage mass as well as leaf area of the plants were evaluated at corn tasseling and when grains reached physiological maturity. Components of corn production were determined in the second sampling. In palisadegrass, water influenced only tillering, which was reduced in the plots in which water defict was forced at the moment of germination or at the beginning of tilering, in both cultivation systems. Plant height and DM production were affected only by cultivation, reducing when intercropped with corn. Evaluated production components did not influence corn grain productivity, which was similar in all treatments (average of 10,145 kg/ha). Palisadegrass plants produce more DM in single cultivation than intercropped with corn. Water deficit during germination and initial tillering reduces tillering of palisadegrass during establishment phase. Water deficit, applied in this trial, does not reduce DM yield in palisadegrass or corn.
  • Authors:
    • Dela Piccolla, C.
    • Mafra, A. L.
    • Pelissari, A.
    • de Moraes, A.
    • da Veiga, M.
    • Balbinot Junior, A. A.
  • Source: Pesquisa Agropecuária Brasileira
  • Volume: 46
  • Issue: 10
  • Year: 2011
  • Summary: The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha(-1) of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.