Souza A.L.,Sao Paulo State University |
De Fatima Sales J.,Do Instituto Federal Goiano |
Campos R.C.,Discente do Curso de Graduacao em Agronomia |
Neto A.R.,Bolsista de PNPD |
Semina:Ciencias Agrarias | Year: 2014
The objective of this study was to evaluate the effect of immersion for varying periods in different concentrations of gibberellic acid and separate methods of scarification on the germination of seeds tucum. In the first trial, testing different soaking periods (24 and 48 hours), different forms of soaking (fast and slow) and different concentrations of gibberellic acid (0 , 100 and 200 mg L-1 ) compared to the control (water) under completely randomized design in a factorial 2x2x3. The second experiment evaluated the different scarification treatments being: physical (seed coat removal in the hilar region with the aid of a scalpel), chemical (sulfuric acid 98 PA for 2:04 minutes) and thermal (hot water at approximately 98 °C and cold water at about 2°C for 4 minutes). In the first trial were evaluated % of contaminated seeds (seeds infected by microorganisms) and hard seeds ( who did not start the germination process , but not soiled), and in the second we assessed germination percentage (%) every two days for three months; germination Speed Index (GSI), time to occurrence of 50 % germination (T50) and Emergency Speed Index (ESI). The use of gibberellic acid was ineffective in promoting germination of Tucum (Astrocaryum Huaimi Mart.). Scarification treatments were effective in promoting germination and emergence of seedlings in the nursery and the most efficient physical removal scarification of the seed coat in the hilar region with the highest percentage of germination.
Structural changes in latosols of the cerrado region: I - relationships between soil physical properties and least limiting water range [Alterações estruturais de latossolos representativos da região do cerrado: I - relações entre propriedades físicas do solo e intervalo hídrico ótimo]
Severiano E.C.,Federal University of Goais |
de Oliveira G.C.,Federal University of Lavras |
Junior M.S.D.,Federal University of Lavras |
Costa K.A.P.,IFGoiano |
Filho S.M.,University of Rio Verde
Revista Brasileira de Ciencia do Solo | Year: 2011
The agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected from the B horizons of five oxidic Latosols representing the textural variability of the Latosols of the Cerrado biome. LLWR and other soil physical properties were determined at various soil compaction degrees induced by uniaxial compression. Soil compaction caused effects varying from enhanced plant growth due to higher water retention, to severe restriction of edaphic functions. Also, inverse relationships were observed between clay content and bulk density values (Bd) under different structural conditions. Bd values corresponding to critical soil macroporosity (Bdc MAC) were more restrictive to a sustainable use of the studied Latosols than the critical Bd corresponding to LLWR (Bdc LLWR). The high tolerable compression potential of these oxidic Latosols was related to the high aeration porosity associated to the granular structure.
Storck L.,Federal Technological University of Parana |
Modolo A.J.,Federal Technological University of Parana |
Brum B.,Federal Technological University of Parana |
Trogello E.,IFGoiano |
And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2015
This study was carried out aiming to obtain a measure of regularity (MR) of spacing of maize plants and the optimal number of plants to estimate the MR in different management systems. In the first study the effects of four straw managements in main plots, two mechanisms using furrowers (double disc and shank) in subplots, and two machine speeds (4.5 and 7.0 km h-1) in the subsubplots were evaluated. In the second study, four grazing intensities in main plots and two mechanisms with furrowers in subplots were assessed. The production of grain and the distance between the 40 plants in a row in the first study and 18 plants in the second study were evaluated. For each experimental unit, the mean distance between plants was observed and calculated MR. The analysis of variance for the grain yield, the mean distances and the MR was performed for the model of each study. To estimate MR, it is sufficient to use the measurements of the distances between 26 corn plants for management of straw study, and 16 corn plants for the study of grazing. The statistic called “measure of regularity” can be used to assess the accuracy of distribution of corn seeds or plants and it can be applied in cases of technical operation reports of seeders. © 2015, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved.
de Oliveira M.C.,University of Rio Verde |
da Silva R.P.,Graduando de Zootecnia |
Araujo L.S.,Graduando de Zootecnia |
da Silva V.R.,Graduando de Zootecnia |
And 2 more authors.
Revista Brasileira de Zootecnia | Year: 2012
This experiment assessed the effect of feed restriction in rabbits on performance and economic viability of the activity. Sixty New Zealand White rabbits, weaned at 33 days and slaughtered at 81 days of age, were used. The design was of randomized blocks with four treatments and five replications. The treatments were, as follows: 1 - free feeding, 2 - feed restriction from 35 to 40 days of age (50 g/d/rabbit), 3 - feed restriction from 54 to 61 days of age (90 g/d/rabbit) and 4 - feed restriction from 33 to 40 days (50 g/d/rabbit) and from 54 to 61 days of age (90 g/d/rabbit). There was no difference in the performance and carcass parameters, indicating that there was compensatory growth in the rabbits that suffered feed restriction. The best gross margin was obtained with feed restriction from 54 to 61 days age. Feed restriction in growing rabbits can be adopted at different ages because it does not interfere negatively in the performance and carcass parameters. In two periods and from 51 to 61 days, feed restriction was more economically viable for the sale of live and slaughtered rabbits, respectively. © 2012 Sociedade Brasileira de Zootecnia.
Galvao J.C.C.,Federal University of Vicosa |
Miranda G.V.,Ceres |
Trogello E.,IFGoiano |
Fritsche-Neto R.,University of Sao Paulo
Revista Ceres | Year: 2014
The objective of this work was to compare the maize production system recommended in the decade of 1940 with the system currently employed in Brazil. We used the paper published by Antônio Secundino de São José at Revista Ceres in 1944 to compare the agricultural practices used at that time with the ones currently employed. In the 40's, we found no direct concern with aspects of soil and water conservation. However, the process of raising grain yield based on the use of more on-farm inputs , such as manure and seeds, was initiated at that time. The maize crop was treated as a sole enterprise without the concepts of integrating crop-livestock and soil and water conservation. Currently, many concepts recommended 70 years ago are still on use in the organic and smallholder farming systems. On the other hand, the large-scale maize cultivation have used a large number of varied inputs such as synthetic fertilizers, herbicides, insecticides, fungicides, hybrid seeds (transgenic or not), planting and harvesting machinery.We conclude from the literature reviewed that in the last 70 years many chances have occurred in maize production system which were essential for the productivity to have increased 3.79 times in the period analyzed. The entire production system was modified in relation to the construction and protection of productivity, which in turn, gave support to Brazil to become the third-largest world producer and exporter of maize, increasing from 5.6 million tons in 1944 to 81.5 million tons in 2013.