Ferreira A.S.,State University Londrina |
Zucareli C.,State University Londrina |
Junior A.A.B.,Embrapa Soja |
Werner F.,State University Londrina |
Coelho A.E.,Producao Vegetal
Semina:Ciencias Agrarias | Year: 2017
The seeding rate influences the intraspecific competition, which might affect the development and quality of seeds in soybean. However, the impact of seeding rate on the physical and physiological qualities of soybean seeds needs to be better elucidated. This study aimed to evaluate the effects of soybean plant density on the seed size as well as the effects of the interaction between the plant density and seed size on the seed mass, green seed occurence, and physiological seed quality. The experiments were carried out in the growing seasons of the years 2013/14 and 2014/15 in a Latossolo Vermelho distroférrico, under a randomized complete block design, using the NK 7059 RR cultivar with six replications. Four plant densities (150, 300, 440, and 560 thousand viable seeds ha-1) were evaluated. After the classification of seeds into four sizes, using a set of sieves, a 4 ×4 factorial scheme was used for the statistical analysis of the four plant densities and four seed sizes. The seed samples were evaluated for the seed mass, green seed percentage, germination, and vigor. Under thermal and water stress during seed development, an increase in the seeding rate led to a reduction in the green seed occurrence and an increase in the seed size and mass. However, in the absence of thermal and water stress, the seed size and mass were not altered by the seeding rate and, there was no occurrence of green seeds.
Silva A.C.,Federal University of Vales do Jequitinhonha and Mucuri |
Canellas L.P.,State University of Norte Fluminense |
Olivares F.L.,State University of Norte Fluminense |
Dobbss L.B.,Producao Vegetal |
And 4 more authors.
Revista Brasileira de Ciencia do Solo | Year: 2011
Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS), humic (HA) and fulvic acids (FA) isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic) in the Serra do Espinhaço Meridional, state of Minas Gerais. Dose-response curves were established for the number of lateral roots growing from the main plant axis of tomato seedlings. The bioactivity of HA was greatest (highest response in lateral roots at lowest concentration) while FA did not intensify root growth. Both HS and HA stimulated root hair formation. At low concentrations, HS and HA induced root hair formation near the root cap, a typical hormonal imbalance effect in plants. Transgenic tomato with reporter gene DR5::GUS allowed the observation that the auxin-related signaling pathway was involved in root growth promotion by HA.
Valdebenito-Sanhueza R.M.,Proterra |
Cantillano R.F.F.,Embrapa Clima Temperado |
Bartnicki V.A.,Producao Vegetal |
Spolti P.,Brazilian National Council for Scientific and Technological Development
Revista Brasileira de Fruticultura | Year: 2016
Bull’s eye rot (Cryptosporiosis perennans) and white rot (Botryosphaeria dothidea) are among the major apple summer diseases in Brazil. The aim of this study was to evaluate the effect of a protective film consisting of carnauba wax and clay (Raynox®) at doses of 2.5% and 5.0% in infection of C. perennans and B. dothidea in ‘Fuji Standard’ and ‘Pink Lady’ apple cultivars. Apple trees were sprayed five times from December 2007 to March 2008, as predicting of adequate conditions for the occurrence of fruit damage and growth. At harvest, the apples were inoculated with both pathogens and evaluated for incidence of decay. Indifferent to dose, the use of Raynox® reduced the incidence of white rot and bull’s eye rot in 67% and 42% in ‘Fuji Standard’, and 43% and 42% in ‘Pink Lady’, respectively. Increasing the dose increased the efficiency of the product for the control of bull’s eye rot. At dose of 2.5%, control of bull’s eye rot was 19% and 20%, respectively, of ‘Fuji Standard’ and ‘Pink Lady’ apples, while for the same cultivars, but with dose of 5.0%, these values were 65% and 63%. More studies are needed to adjust the dose and application criteria for the sunburn protectant could be recommended. © 2016, Sociedade Brasileira de Fruticultura. All rights reserved.
Rocha R.S.,Producao Vegetal |
Da Silva J.A.L.,CCA UFPI |
Neves J.A.,Producao Vegetal |
Sediyama T.,Federal University of Viçosa |
Teixeira R.C.,Federal University of Viçosa
Revista Ciencia Agronomica | Year: 2012
This study had as its objective to evaluate the agronomic performance of soybean varieties and strains grown under low-latitude conditions in Teresina, PI. Phenological traits, yield, and characteristics related to the development of soybean plants from 32 genotypes taken from pre-launch strains and varieties were evaluated, some already launched in states in the midwest region of Brazil. The experimental design used was of randomized blocks with four replications. Under the conditions studied, 13 genotypes (nine varieties and four strains) were identified as having good agronomic performance in low latitudes, with an average grain yield of over 2,900kg ha-1 (48.3 sacks of 60kg ha-1). Of those genotypes studied, based on certification of BRS Sambaíba and Msoy 9350, those that stood out most for the traits assessed and for satisfactory mechanical harvesting under low-latitude conditions, were the Conquista and Valiosa RR varieties and the strains BCR892 G132, BCR651 G75 and BCR6651 G68.
Camargo C.K.,State University of the Central West |
De Resende J.T.V.,UNICENTRO |
Camargo L.K.P.,Federal University of Paraná |
Figueiredo A.S.T.,Producao Vegetal |
Zanin D.S.,Producao Vegetal
Semina:Ciencias Agrarias | Year: 2012
The organic agriculture has been increasing in recent years, mainly because it is a production system that is socially, economically and ecologically correct. Mineral nutrition in alternative production systems is a determining factor for the success of crops. This study aimed to evaluate desirable agronomic traits of strawberry under different levels of cattle manure and rock waste. The experiment was conducted in the Department of Vegetable Crops in the UNICENTRO Guarapuava/PR. The fruits were collected from October 2008 to January 2009. We used the following treatments: 0, 50 and 100 t ha-1 of cattle manure and 0, 2, 4 and 6 t ha-1 of rock waste. The variables were evaluated productivity, commercial production and average mass of fruits. The average mass of fruit was not influenced by levels and sources of fertilizer. The results have revealed that both productivity and the commercial production of fruits performed better in the association of higher levels of cattle manure with intermediate levels of rock waste.
Paes H.M.F.,Producao Vegetal |
Esteves B.S.,Programa de Pos Graduacao em Producao Vegetal |
De Sousa E.F.,Producao Vegetal
Revista Ciencia Agronomica | Year: 2012
This study was carried out to describe the water needs of okra at each stage of its development, through the determination of crop evapotranspiration and crop coefficient (kc) providing subsidies to irrigated agriculture. The experiment was conducted at Station evapotranspirometers Universidade Estadual do Norte Fluminense Darcy Ribeiro in Campos State, Brazil. The cultivar used was the Santa Cruz 47, planted in a spacing of 0.25 mx 1.00 m in an area of 1024 m 2, irrigated by sprinkler. Area was done to determine the evapotranspiration and Kc, using a lysimeter 6 m2 with an electronic scale with weight change of 0,58 kg. The results allowed to quantify the crop evapotranspiration during the period under 314 mm. The Kc of okra in the first stage of development varied between values of 0.8 and 0.5, obtaining the average value of 0.68, the second stage ranged from 0.5 to 1.0, with a mean of 0,79,and the third stage Kc ranged from 1.0 to 0.3, the average being 0.54.
Coelho M.S.,Novo A/S |
de Mendonca E.S.,Federal University of Espirito Santo |
de Lima P.C.,Empresa de Pesquisa Agropecuaria de Minas Gerais |
Guimaraes G.P.,Producao Vegetal |
Cardoso I.M.,Federal University of Viçosa
Revista Brasileira de Ciencia do Solo | Year: 2013
The input of organic residues associated with the humification process promotes improvement of soil properties and enables the sustainability of the production system. Aside from supplying the coffee with nutrients, pulse crops can improve the quality of soil organic matter by forming humic substances. The purpose of this study was to evaluate the effect of green manures legumes on the quality of humic substances in soils under coffee under two environmental conditions in the region of Zona da Mata, in Minas Gerais. The species forage peanut, calopo, stylosanthes, velvetbean and spontaneous species were grown for four years on two family farms. After four years, soil was sampled and the humic substances were extracted and purified to obtain fulvic acids (FA) and humic acids (HA). The elemental sample composition (CHNO analyzer), UV-visible, infrared and thermogravimetry of the purified material were analyzed. The results showed that HA have a higher molecular weight, hydrophobicity, condensation, and aromatic compounds with higher C content, providing greater structural stability than FA. The humic substances in the environment facing south, with lower light incidence, lower temperatures and higher humidity, were structurally more stable and decay-resistant than the humic substances extracted from soil northwest-oriented soil surfaces. In the treatment with calopo, FA contained low C and high O levels, characterizing compounds of lower structural stability than FA in the treatments with stylosanthes, velvetbean and spontaneous species. In HA, the use of legumes showed similar results.
Camacho M.A.,State University of Mato Grosso do Sul |
da Silveira M.V.,Producao Vegetal |
Camargo R.A.,Producao Vegetal |
Natale W.,São Paulo State University
Revista Brasileira de Ciencia do Solo | Year: 2012
use of nutritional diagnoses methods to define ideal and critical nutrient concentrations in plant tissues has proved promising, provided the limits are known. This study determined the normal nutrient ranges for an orange pear population, using the methods mathematical chance (MCh), Integrated Diagnosis and Recommendation (DRIS) and Compositional Nutrient Diagnosis (CND), in addition to the critical level by the reduced normal distribution method. The study was conducted in Bebedouro, São Paulo state, at the Experimental Station of Bebedouro. The total nutrient contents of 50 leaf samples and orange pear yield from an experiment to test applied limestone rates were used as database. For N, the highest value was obtained by MCh class 2 (23.6-24.7 g kg-1), with values similar to those obtained by DRIS (22.1-24.0 g kg-1) and CND (22.1-23.9 g kg-1). Values below these normal ranges agree with the critical level reached (22.7 g kg-1), which is very close to the threshold proposed in the literature. For P, K, Mg, Zn, and B, normal nutrient ranges and critical levels were distant from those reported in the literature. The Ca, Fe, Mn, and Cu values of the normal range and critical level approached the recommended limits, possibly due to a greater variation in the levels. The proposed methods for a population were more appropriate when variation in nutrient content was greater. The amplitude of normal range was narrower than the range of sufficiency levels found in the literature.
Neumann M.,State University of the Central West |
Figueira D.N.,Federal University of Rio Grande do Sul |
Ueno R.K.,Producao Vegetal |
Leao G.F.M.,State University of Maringá |
Semina:Ciencias Agrarias | Year: 2015
The aim of the study was to evaluate the performance, apparent digestibility of dry matter and feeding behavior of Dutch steers fed different diets in feedlot. Were used 36 Holstein calves, from the same herd, with an average of 192 days and an average body weight of 221kg age. The experimental diets consisted of: T1: 100% concentrate diet; T2: 55% concentrate diet + corn silage; and T3: 55% concentrate diet+oat hay, and six replicates, where each replicate was a stall with two animals. Was no significant difference between treatments, and the treatment consists of the 100% concentrate diet had higher performance results with an average daily gain of 1.350 kg day-1; and feed conversion of 5.28 dry matter intake of 6.84. We evaluated also the 100% diet also influenced the feeding behavior, and the time for rumination, food consumption and water intake are respectively 2.75; 1.14; 0.15 hours day-1. The digestibility of dry matter was also a significant difference to the diet 100%, and this was around 76.37%. The diet showed 100% concentrate in terms of performance, an interesting alternative for termination of Holstein steers.
Pereira T.,University of West Santa Catarina |
Coelho C.M.M.,Santa Catarina State University |
Souza C.A.,Producao Vegetal |
Mantovani A.,UNOESC |
Semina:Ciencias Agrarias | Year: 2015
The use of desiccants is an alternative to anticipate the soybean harvest and keep the physiological quality of seed. The objective of this work was to assess the production performance and germination seeds in response to differents stages and desiccation chemicals products to early harvest of soybean cultivars. The experiment was conducted in Campos Novos, in two harvests, it was used a randomized complete block design disposed in split-split-plots. Two phonological stages of application (stage R7.1 and R7.3) were tested in the main plot. Five soybean cultivars (NA 5909 RG, CD 2585 RR, BMX Turbo RR, SYN 1059 RR and BENSO 1RR were evaluated in the subplots, and three desiccants ammonium glufosinate, paraquat, carfentrazone-ethyl in the 2011/12 season and one control (without the desiccant application) were evaluated in the sub-subplots. In the 2012/13 season the carfentrazone-ethyl was substituted by diquat. It were evaluated the number of the days in the early harvest, yield, number of pods per plant, number of seeds per pod, mass of 100 seeds and germination percentage. The chemical dessecation with the use of glufosinate ammonium and paraquat applied in R7.1 stadium allowed to anticipate the harvest in six days (2011/12) and provided maintenance germination percentage (90% and 92%) compared to control (76%). The dessecation didn't influence negatively on seeds productivity, but reduced the mass of seeds in the two grown season, and early harvest was dependent of pre-harvest rain absence, with this preamble. The use of dessicants is a possibility of early harvest in production field of soybean seeds.