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Search Results: 1 - 10 of 181316 matches for " Silvério de Paiva;Candido "
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Análise biométrica de ganhos por sele??o em popula??o de milho pipoca de quinto ciclo de sele??o recorrente
Rangel, Ramon Macedo;Amaral Júnior, Antonio Teixeira do;Gon?alves, Leandro Sim?es Azeredo;Freitas Júnior, Silvério de Paiva;Candido, Liliam Silvia;
Revista Ciência Agron?mica , 2011, DOI: 10.1590/S1806-66902011000200029
Abstract: aiming to select superior progenies for concentration of favorable alleles in a popcorn population on the fifth cycle of intrapopulation full-sib recurrent selection, two hundred progenies were evaluated for six agronomic traits, including grain yield and popping expansion, in randomized complete block design with two replications within sets, in two distinct environments: colégio estadual agrícola ant?nio sarlo, in campos dos goytacazes, and experimental station of pesagro-rio, located in itaocara, rio de janeiro state, in 2007/2008. there were significant differences among families within sets in all traits, indicating the presence of genetic variability to be exploited in the future cycles. the utilized selection indexes were the mulamba and mock; and smith and hazel. the mulamba and mock index propitiated more elevated magnitudes of the predicted gains for most of the traits, including popping expansion and grain yield, with values of 6.01 and 8.53%, respectively, utilizing arbitrary weight attributed by tentative.
Recurrent selection in inbred popcorn families
Daros, Máskio;Amaral Jr., Ant?nio Teixeira do;Pereira, Messias Gonzaga;Santos, Fabrício Santana;Gabriel, Ana Paula Candido;Scapim, Carlos Alberto;Freitas Jr., Silvério de Paiva;Silvério, Lucas;
Scientia Agricola , 2004, DOI: 10.1590/S0103-90162004000600008
Abstract: although much appreciated in brazil, commercial popcorn is currently cropped on a fairly small scale. a number of problems need to be solved to increase production, notably the obtaintion of seeds with good agronomic traits and good culinary characteristics. with the objective of developing superior genotypes in popcorn, a second cycle of intrapopulation recurrent selection based on inbred s1 families was carried out. from the first cycle of selection over the unb-2u population, 222 s1 families were obtained, which were then divided into six sets and evaluated in a randomized complete block design with two replications within the sets. experiments were carried out in two brazilian localities. the analysis of variance revealed environmental effects for all evaluated traits, except popping and stand, showing that, for most traits, these environments affected genotype behavior in different ways. in addition, the set as source of variation was significant for most of the evaluated traits, indicating that dividing the families into sets was an efficient strategy. genotype-by-environment interaction was detected for most traits, except popping expansion and stand. differences among genotypes were also detected (1% f-test), making viable the proposition of using the genetic variability in the popcorn population as a basis for future recurrent selection cycles. superior families were selected using the smith and hazel classic index, with predicted genetic gains of 17.8% for popping expansion and 26.95% for yield.
Palha de cana-de-a?úcar associada ao herbicida trifloxysulfuron sodium + ametryn no controle de Rottboellia exaltata
Oliveira, Anderson Ramos de;Freitas, Silvério de Paiva;
Bragantia , 2009, DOI: 10.1590/S0006-87052009000100020
Abstract: the objective of this work was to evaluate the sugarcane straw potential and the association between the straw and the commercial mix of the trifloxysulfuron sodium + ametryn to control itchgrass (rottboellia exaltata l.). the experiment was developed in the universidade estadual do norte fluminense darcy ribeiro (uenf), campos dos goytacazes rio de janeiro state, brazil, from september to november 2004. it was carried out in randomized blocks, with the treatments arranged in a factorial scheme: five layers of straw (0; 4; 8; 12 e 16 t ha-1) and five doses of trifloxysulfuron sodium + ametryn (0,0; 1,0; 1,5; 2,0 e 2,5 kg ha-1), with four replications. the herbicide was applied in post-emergence, when weeds (r. exaltata) height was between 5 and 10 cm. number of weeds was evaluated at 15, 30, 45 and 60 days after herbicide application. the herbicide concentration that inhibits 50% of the weed emergency (i50) was determined. in the sixty day, the itchgrass plants were collected and dry biomass was determined. the interaction between straw quantity and doses of trifloxysulfuron sodium + ametryn was significant. straw layer of 16 tha-1 without herbicide addition was efficient to control r. exaltata and the herbicide trifloxysulfuron sodium + ametryn at 2,5 kg ha-1 used alone was efficient to control this weed. straw levels between 8 and 12 t ha-1 intercepted the herbicide and consequently, increased the i50 value. in other words, the concentration of the herbicide to inhibit 50% of the weeds growth was greater when there were 8 and 12 t ha-1 than when there was 4 t ha-1 of straw.
Eficiência de trifloxysulfuron-sodium no controle de Cyperus rotundus L. na cultura da cana-de-a?úcar
Oliveira, Anderson Ramos de;Freitas, Silvério de Paiva;Freitas, Ismael Louren?o de Jesus;
Revista Ceres , 2010, DOI: 10.1590/S0034-737X2010000600006
Abstract: the aim of this study was to evaluate the efficiency of trifloxysulfuron-sodium used alone, mixed or in sequential application with other herbicides to control cyperus rotundus l. in sugar cane. the study was conducted in an area of commercial production of variety rb 72-454 at "paraíso plant" and a greenhouse at the state university "darcy ribeiro", campos dos goytacazes, rj. the field plots were subjected to nine treatments: 2,4-d; trifloxysulfuron-sodium + ametryn; trifloxysulturon-sodium, 2,4-d + 2,4-d (20 days after the first application -dap) 2, 4-d + ametryn trifloxysulfuron-sodium (20 dap), 2,4-d + trifloxysulfuron-sodium (20 dap); halosulfuron (20 dap), control with and without hand weeding. the greenhouse trial evaluated the viability of purple nutsedge bulbs as a function of the treatments used in the experiment carried out in the field. the results indicated that the trifloxysulfuron-sodium applied alone or mixed with ametryn in sequential application to 2,4-d was excellent in controlling c. rotundus. these herbicides, along with halosulfuron applied alone reduced the capacity for reinfestation of this specie by reducing propagation and growth.
Caracteriza??o da pra?a Dr. Augusto Silva localizada na Cidade de Lavras/MG
Carvalho, Larissa Martiniano de;Paiva, Patrícia Duarte de Oliveira;Coelho, Silvério José;
Ciência e Agrotecnologia , 2003, DOI: 10.1590/S1413-70542003000300004
Abstract: city squares present important roles in urban environment such as community integration and improvement of environmental quality. to analyze the actual situation of the dr. augusto silva city square an evaluation of its characteristics and uses was performed through a qualitative analysis and a pool within its users. urbanistic, physical aspects, and vegetation were evaluated using the qualitative analysis. the pool was applied in members of 600 families using a standardized questionnaire with direct and descriptive questions. the results showed that dr. augusto silva is the most visited city square by residents of the entire town. the activities in this square are varied including rest and sportive practices even though it lacks some basic infrastructures. based on the qualitative analysis it was observed that this square present a regular to good maintenance.
Efeito residual da aplica??o de fluazifop-p-butil + fomesafen em solos com plantas-teste
Silva, Carlos Magno Magalh?es da;Freitas, Silvério de Paiva;Rosa, Raul Castro Carrielo;
Ciência Rural , 2007, DOI: 10.1590/S0103-84782007000500037
Abstract: it was carried out an assay in order to evaluate the residual effect of the ready mixture fluazifop-p-buthyl + fomesafen (160+200g ha-1), present in the soils yellow argisoil (ya) and yellow latosol (yl), in the increase of pumpkin, cucumber, maize and passion fruit, used as test plant. it was not verified difference in relation to dry matter of the aerial part of test plant in the same soil, the same was verified to dry matter of the root, excepted passion fruit in la. independently of the analyzed soils, the herbicide residues present in the substrate resulted in reduction of germinated broadleaved weed, without reducing the total number of weed.
Associa??o entre características agron?micas e capacidade de expans?o em popula??o de milho pipoca sob sele??o recorrente
Rangel, Ramon Macedo;Amaral Júnior, Antonio Teixeira do;Freitas Júnior, Silvério de Paiva;
Ciência e Agrotecnologia , 2011, DOI: 10.1590/S1413-70542011000200001
Abstract: the objective of this work was to investigate the possibility of a more efficient selection through path analysis and partial correlation in the breeding program of the uenf popcorn population by recurrent selection. two hundred full-sib progenies were obtained and evaluated by eight traits in two environments in rio de janeiro state: campos dos goytacazes and itaocara. the genotypic correlation between popping expansion and grain yield was negative and non significant at the 5% probability level by t test. path analysis showed that mass weight of 100 grains is the most associated trait at popping expansion in this study. it is possible to obtain correlated response for popping expansion by grain yield, as long as genotypes with smaller grain size are selected from the genotypes with higher grain yield.
Dynamics of populations of weed in the sugarcane in system no-tillage and conventional one1 / Dinamica de popula es de plantas daninhas na cana-de-a úcar em sistema de plantio direto e convencional1
José Barbosa Duarte Júnior,Silvério de Paiva Freitas,Fábio Cunha Coelho
Semina : Ciências Agrárias , 2009,
Abstract: O objetivo deste trabalho foi avaliar a incidência e a dinamica de popula es de plantas daninhas na cultura da cana-de-a úcar em sistema de plantio direto (SPD) em compara o ao preparo convencional (PC), após tratamento com herbicidas. O delineamento experimental foi em blocos casualizados, com quatro repeti es, num esquema fatorial 4x2. Os tratamentos foram: (I) – cana PC vegeta o espontanea incorporada com aduba o e (II) – idem I sem aduba o; (III) – cana SPD sobre palhada feij o-de-porco com aduba o e (IV) – idem III sem aduba o; (V) – cana SPD sobre palhada de mucuna preta com aduba o e (VI) – idem V sem aduba o e (VII) – cana SPD sobre palhada de crotalária juncea com aduba o e (VIII) – idem VII sem aduba o. As espécies Cyperus rotundus e Sorghum halepense apresentaram os maiores índices de valor de importancia na área experimental. O SPD de cana-de-a úcar sobre feij o-de-porco apresentou o menor índice de similariedade na comunidade de plantas daninhas em rela o à cana cultivada convencionalmente. A incidência de plantas daninhas na cana PC foi 531 e 525% superior à cana SPD e contribuiu para a redu o de 27% na produtividade. The research aimed to evaluate the incidence and the populations dynamics in sugarcane crop in no-tillage system in comparison to the conventional one. The experimental design was completely random, using four replications, in a factorial 4x2 outline. The treatments were: (I) – sugarcane PC incorporated to spontaneous vegetation with manuring and (II) – the same procedure as in I without manuring; (III) – sugarcane SPD over jack bean (Canavalia ensiformis) with manuring and (IV) – the same procedure as in III without manuring; (V) – sugarcane SPD over velvet bean (Mucuna aterrima) with manuring and (VI) – the same procedure as in V without manuring and (VII) – sugarcane SPD over sunnhemp (Crotalaria juncea) with manuring and (VIII) – the same procedure as in VII without manuring. The species Cyperus rotundus and Sorghum halepense presented the highest rates of value of importance in the experimental area. Sugarcane SPD over jack bean presented the lowest similarity rate in the community of weed in relation to the sugarcane cultivated conventionally. The incidence of weed in the sugarcane PC was 531 and 525% superior in to the sugarcane SPD, and contributed to the reduction of 27% in the yield.
Phytosociological aspects and weed management using cover crops on organic conilon coffee plantations / Aspectos fitossociológicos e manejo de plantas espontaneas utilizando espécies de cobertura em cafeeiro Conilon organico
Fábio Luiz Partelli,Henrique Duarte Vieira,Silvério de Paiva Freitas,José Antonio Azevedo Espindola
Semina : Ciências Agrárias , 2010,
Abstract: Weeds can bring benefits to agriculture, but when incorrectly managed they can compete with commercial crops for resources. The objective of this work was to evaluate the effect that cover crops, associated with Coffea canephora cv. Conilon, imposes to the weed community. Cover crops were planted between the rows of a 6.5 years old organic coffee plantation spaced 2.0 x 1.5 m. The experiment was arranged in a complete randomized block design, with four replications, in a factorial scheme with the following treatments: control, Pennisetum glaucum and the legume plants: Canavalia ensiformis, Mucuna deeringiana and Cajanus cajan, with and without Rizobium inoculation. Cover crops dry weight and nutrient contents on coffee trees were determined. Weeds density, frequency, relative abundance, importance value index and plant similarity index were also determined. Twenty seven weed species were identified, with special emphasis on Bidens subalternans and Commelina benghalensis. Cover crops promote modifications on the succession dynamics of weeds and do not interfere with the development of the coffee trees. Canavalia ensiformis, Mucuna deeringiana and Pennisetum glaucum help on weed control. As plantas espontaneas competem com as culturas por recursos escassos, quando mal manejadas. No entanto, podem trazer benefícios à agricultura. O objetivo desse trabalho foi avaliar o efeito que plantas de cobertura, consorciadas com Coffea canephora cv. Conilon, imp em à comunidade de plantas espontaneas. Plantas de cobertura foram semeadas nas entrelinhas de um cafezal de 6,5 anos conduzido sob manejo organico, com espa amento de 2,0 x 1,5 m. O delineamento experimental foi de blocos ao acaso, com quatro repeti es, num arranjo fatorial com tratamentos adicionais: testemunha, milheto – Pennisetum glaucum, e as leguminosas feij o-de-porco – Canavalia ensiformis, mucuna-an – Mucuna deeringiana, e feij o-guandu – Cajanus cajan, com e sem inocula o com rizóbio. Foram determinados a matéria seca das plantas de cobertura e as concentra es de nutrientes no cafeeiro. Determinou-se ainda a densidade, frequência e abundancia relativas, assim como o índice de valor de importancia e de similaridade das plantas espontaneas. Foram identificadas 27 espécies, destacando-se Bidens subalternans e Commelina benghalensis. As espécies de cobertura promovem modifica es na popula o de plantas espontaneas e n o prejudicam o cafeeiro. Feij o-de-porco, mucuna-an e milheto auxiliam na supress o de plantas espontaneas.
Genetic gains in popcorn by full-sib recurrent selection
Silvério de Paiva Freitas Júnior,Antonio Teixeira do Amaral Júnior,Ramon Macedo Rangel,Alexandre Pio Viana
Crop Breeding and Applied Biotechnology , 2009,
Abstract: The purpose of this study was to investigate the genetic progress in the fourth selection cycle of full-sibpopcorn families. Two hundred families were evaluated for six agronomic traits, including grain yield (GY) and poppingexpansion (PE), in a random block design with two replications, in sets in two different environments: Campos dos Goytacazesand Itaocara, in the State of Rio de Janeiro. There were significant differences among families within sets in all traits,indicating the presence of genetic variability to be exploited in the future cycles. The family by environment in the sets for GYand PE was significant but simple, indicating the possibility of conducting a single breeding program for both locations. Therelease of the improved variety for producers of the Northern and Northwestern regions of the State of Rio de Janeiro isexpected after the fifth cycle.
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