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Item Avaliação da resistencia a ferrugem tropical em linhagens de milho(1996) Lima, Marlene; Paterniani, Maria Elisa Ayres Guidetti Zagatto; Dudienas, Christina; Siqueira, Walter José; Sawazaki, Eduardo; De Sordi, GuidoFour hundred and forty maize inbred lines, developed at Instituto Agronômico de Campinas, State of São Paulo, Brazil, derived from several populations, were evaluated, in field conditions, as to tropical rust resistance caused by Physopella zeae. Twenty two experiments were carried out in randomized complete block designs, with two replications each, during 93/94 summer season, in Ribeirão Preto, State of Sao Paulo, Brazil. Resistant (Z 8568) and susceptible (P 3069) hybrids were used as controls. The evaluations were performed 30 days after flowering, according to a scale of notes from 1 to 9 (0%; 1%; 2.5%; 5%; 10%; 25%; 50%; 75% and >75% affected leaf area). All populations showed variability as to P. zeae reaction, suggesting that recurrent selection might be effective to achieve tropical rust resistance. Avaliaram-se 440 linhagens endogâmicas de milho do Instituto Agronômico de Campinas, obtidas a partir de diversas populações, quanto à severidade da ferrugem tropical, causada por Physopella zeae, em condições naturais de infecção. Foram instalados 22 experimentos em blocos ao acaso com duas repetições, em 1993/94, em Ribeirão Preto (SP) e utilizados como testemunhas resistente e suscetível os híbridos Z 8568 e P 3069 respectivamente, incluídos de forma intercalar. A avaliação foi realizada aos 30 dias após o florescimento, mediante uma escala de notas de 1 a 9, correspondendo a 0%; 1%; 2,5%; 5%; 10%; 25%; 50%; 75% e >75% de área foliar afetada. Todas as populações estudadas apresentaram variabilidade quanto à resistência a P. zeae, indicando que a utilização de métodos de seleção recorrente pode ser eficaz no melhoramento de populações visando à resistência ao patógeno.Item Avaliação da resistencia a ferrugem tropical em linhagens de milho(1996) Lima, Marlene; Paterniani, Maria Elisa Ayres Guidetti Zagatto; Dudienas, Christina; Siqueira, Walter José; Sawazaki, Eduardo; De Sordi, GuidoFour hundred and forty maize inbred lines, developed at Instituto Agronômico de Campinas, State of São Paulo, Brazil, derived from several populations, were evaluated, in field conditions, as to tropical rust resistance caused by Physopella zeae. Twenty two experiments were carried out in randomized complete block designs, with two replications each, during 93/94 summer season, in Ribeirão Preto, State of Sao Paulo, Brazil. Resistant (Z 8568) and susceptible (P 3069) hybrids were used as controls. The evaluations were performed 30 days after flowering, according to a scale of notes from 1 to 9 (0%; 1%; 2.5%; 5%; 10%; 25%; 50%; 75% and >75% affected leaf area). All populations showed variability as to P. zeae reaction, suggesting that recurrent selection might be effective to achieve tropical rust resistance. Avaliaram-se 440 linhagens endogâmicas de milho do Instituto Agronômico de Campinas, obtidas a partir de diversas populações, quanto à severidade da ferrugem tropical, causada por Physopella zeae, em condições naturais de infecção. Foram instalados 22 experimentos em blocos ao acaso com duas repetições, em 1993/94, em Ribeirão Preto (SP) e utilizados como testemunhas resistente e suscetível os híbridos Z 8568 e P 3069 respectivamente, incluídos de forma intercalar. A avaliação foi realizada aos 30 dias após o florescimento, mediante uma escala de notas de 1 a 9, correspondendo a 0%; 1%; 2,5%; 5%; 10%; 25%; 50%; 75% e >75% de área foliar afetada. Todas as populações estudadas apresentaram variabilidade quanto à resistência a P. zeae, indicando que a utilização de métodos de seleção recorrente pode ser eficaz no melhoramento de populações visando à resistência ao patógeno.Item Avaliação de cultivares de milho verde em pariquera-açu(1986) Ishimura, Issao; Yanai, Kiyoshi; Sawazaki, Eduardo; Noda, MassaharuTen dent-corn cultivars were evaluated in two planting dates (May and June) at the Pariquera-Açu Experiment Station, State of São Paulo, Brazil, in order to identify the best materials for ear production at grain milk stage. The following characteristics were studied: final stand, number of total ears and commercial ears type, weight of ears with husk, ear index, average weight of commercial ears, plant cycle and plant reaction to natural infection of Helminthosporium turcicum. Among the cultivars tested, statistically significant differences were obtained for final stand, ear index, plant cycle, yield and plant resistance to H. turcicum. The corn cultivars Cargill 408 and Cargill 742 were the most productive, and as compared to Agroceres 162, they matured earlier, yielded higher, showed higher ear index and were less infected by H. turcicum. Despite the atypical and unfavorable local season conditions for the corn crop, the relatively low productivity was still considered profitable for ear production harvested at grain milk stage. Os cultivares de milho Cargill 742, Cargill 408, Cargill 511, Cargill 501, Agroceres 162, Pioneer X 307, IAC Phoenyx 1918, IAC Phoenyx o2 1313, IAC Maya XIX e BR 126 foram avaliados em duas épocas, em plantios de inverno (maio e junho de 1983) na Estação Experimental de Pariquera-Açu, SP, com o objetivo de identificar os melhores para a produção de milho verde. Foram estudadas as seguintes características agronômicas: estande final; número e total de espigas comerciáveis; peso de espigas com palha, comerciáveis e total; índice de espigas (número de espigas comerciáveis/estande final) e peso médio de espigas comerciáveis. Os cultivares se diferenciaram quanto à população final de plantas; índice de espigas; resistência a Helminthosporium turcicum Pass.; ciclo do plantio à colheita, e produtividade: o Cargill 742 e o Cargill 408 foram os mais produtivos, superando o Agroceres 162, e mostraram ainda menor incidência de Helminthosporium turcicum, maior índice de espigas e precocidade. As condições climáticas foram atípicas, desfavoráveis à cultura do milho, provocando baixo nível de produtividade, que ainda foi lucrativo.Item Combining ability and potential of s1 popcorn progenies for early selection(2022) Oliveira, André Luis Bombonato de; Rodrigues, Cinthia Souza; Silva, Guilherme Augusto Peres da; Sawazaki, Eduardo; Barros, Vera Lucia Nishijima Paes de; Paterniani, Maria Elisa Ayres Guidetti ZagattoABSTRACT. Evaluation of combined ability can eliminate lines that are inefficient and enable the subsequent program steps to be more successful. The objective of this study was to predict the general (gi) and specific (sij) combination ability of popcorn S1 progenies for early selection. A total of 288 topcrosses were performed under a randomized complete block design with two replicates at two sites (Campinas and Capão Bonito, São Paulo State, Brazil). Diallel analyses were performed using mixed models and the maximum likelihood restricted/best unbiased linear prediction method. Evaluated traits included grain yield (GY; kg ha-1), weight of 100 grains (g), and popping expansion (PE; mL g-1). Ear components were also evaluated, including ear length, ear diameter (cm), and the number of grain rows (unit). The S1 progeny 32 presented the highest gi for GY in Campinas, whereas progeny 46 presented the highest gi for GY in Capão Bonito. The S1 progeny, 114 was an important parent for the popcorn breeding program, because it presented high gi for the traits of agronomic interest at both sites. Combination 86×IAC12 exhibited a high sij, and the 86 parent presented the second-highest gi for PE in Campinas, and it should be used for high PE genotypes.Item Cruzamentos dialélicos de linhagens de milho sob condições de mancha de Phaeosphaeria(2000) Paterniani, Maria Elisa Ayres Guidetti Zagatto; Sawazaki, Eduardo; Dudienas, Christina; Pereira, José Carlos Vila Nova AlvesSingle-cross hybrids of maize obtained from diallell crosses among ten inbred lines from CIMMYT were grown in four locations of the State of São Paulo, Brazil, during 1996/97, to evaluate stability and adaptability of grain yield. The experiments were set up in a randomized block design with three replications, including four comercial controls. High predictability of grain yield and general adaptability (b=1,0) was observed for most hybrids, indicating that the lines are a potential source of heterosis as well as for good adaptability. A severe infestation of Phaeosphaeria maydis leaf spot occured in Ribeirão Preto, representing a stress factor responsible for reduction of environmental quality. The disease was assessed about 30 days after flowering, using a scale of grades of 1 to 9, for 0% and 80% of the leaf area affected in the adult plant, respectively. There was a tendency of the more resistant materials to show adaptability values lower than 1.0 (b<1.0), being the single correlation between disease evaluation and the regression coefficient b (r=0.353) significant at a 2% t test. Hybrids L04XL10 and L10XL11 showed highest grain yield values, similar to the checks, and presenting stability also. It was noted that L10XL11 was resistant to Phaeosphaeria leaf spot. Híbridos simples de milho resultantes de cruzamentos dialélicos entre dez linhagens endogâmicas provenientes do CIMMYT foram avaliados em 4 locais do Estado de São Paulo (Estações Experimentais do IAC), em 1996/97, quanto à estabilidade e adaptabilidade da produtividade de grãos. Os ensaios foram instalados sob delineamento de blocos casualizados com três repetições, incluindo quatro testemunhas comerciais. Foi verificada grande previsibilidade da produção e adaptabilidade ampla (b=1,0) da maioria dos híbridos, indicando que o conjunto de linhagens é fonte potencial de híbridos heteróticos e de estabilidade satisfatória. Houve intensa severidade da mancha foliar de Phaeosphaeria maydis em Ribeirão Preto, considerada um dos fatores de estresse que mais contribuiu para a redução da qualidade ambiental. A doença foi avaliada cerca de 30 dias após o florescimento, através de uma escala de notas de 1 a 9, correspondendo a 0% e >80% de aréa foliar afetada na planta adulta, respectivamente. Houve uma tendência dos materiais mais resistentes à doença apresentarem valores de adaptabilidade menores que 1,0 (b<1,0), sendo a correlação simples entre notas da doença e coeficientes de regressão b (r=0,353) significativa pelo Teste t a 2% de probabilidade. Os híbridos L04xL10 e L10xL11 tiveram as maiores produtividades do conjunto, não diferiram das testemunhas comerciais e demonstraram estabilidade de produção, sendo o último resistente à mancha de Phaeosphaeria.Item Genetic parameter estimates and identification of superior white maize populations(2017) Rovaris, Sara Regina Silvestrin; Oliveira, André Luís Bombonato; Sawazaki, Eduardo; Gallo, Paulo Boller; Paterniani, Maria Elisa Ayres Guidetti ZagattoABSTRACT. In Brazil, there is a shortage of white maize cultivars and genetic studies for special maize breeding programs. This study aimed to identify populations and promising hybrid white maize for main agronomic traits and grits processing and to estimate the genetic parameters of parents and heterosis. In the 2012/13 growing season, fifteen hybrids were obtained by complete diallel crosses, and six parental and commercial check varieties were evaluated for: female flowering (FF), ear height (EH), grain yield (GY), ear length (EL), volumetric mass (VM) and grits processing (GP) in two locations in São Paulo State, Campinas and Mococa, using a randomized block design. Analyses of variance were carried out, and diallel crosses were performed using the Gardner and Eberhart model. The populations P3 and P6 stood out because of the estimated effects of the parents and of heterosis; the studied characters are promising for obtaining new lines and forming composites. For GP, the treatments showed no differences, implying the need to introduce new sources of germplasm. RESUMO. No Brasil, há uma escassez de cultivares e de estudos genéticos para programas de melhoramento de milhos especiais. Este trabalho teve por objetivos identificar híbridos promissores de milho branco quanto à produtividade e rendimento de canjica e estimar parâmetros genéticos dos genitores e a heterose. Na safra de 2012/13, quinze híbridos obtidos por dialelo completo, seis genitores e uma testemunha comercial foram avaliados quanto aos caracteres: florescimento feminino (FF), altura de espiga (EH), massa de grãos (GY), comprimento de espiga (EL), massa volumétrica (VM) e rendimento de canjica (GP), em dois locais do estado de São Paulo sob delineamento de blocos ao acaso. Efetuaram-se análises de variância e dialélica pelo modelo de Gardner e Eberhart. As populações P3 e P6 destacaram-se por reunir estimativas de efeitos de genitores e de heterose de variedades promissoras para os caracteres estudados, podendo ser utilizados para obtenção de linhagens e formação de compostos. Detectaram-se híbridos promissores para o mercado de milho branco. Para GP os tratamentos não apresentaram diferenças, inferindo a necessidade da introdução de novas fontes de germoplasma.Item Identification of populations and hybrid combinations of maize for in natura consumption(2019) Rocha, Daniel Sarto; Rovaris, Sara Regina Silvestrin; Rodrigues, Cinthia Souza; Ticelli, Marcelo; Sawazaki, Eduardo; Paterniani, Maria Elisa Ayres Guidetti ZagattoABSTRACT Brazil is one of the leading countries in the production of maize (Zea mays), with great potential for growing green maize, which has a superior commercial value in relation to maize marketed in the form of grains. Although important, the availability of cultivars recommended for the production of green maizeis still very scarce. The objectives of the present study were to estimate genetic parameters and to identify promising hybrid combinations for the development of new green maize cultivars to farmers. In the summer crop of 2016/17, ten hybrid combinations obtained through a complete diallel of five maize populations, with attributes for in natura consumption, were evaluated in two sites of the state of São Paulo, Brazil: the Instituto Agronômico(IAC) in Campinas and Tatuí. A randomized block design was used with two additional checks, with three replications, in plots with four five-meter rows spaced by 0.9 m in Campinas and 0.8 m in Tatuí, with 5 plants per meter. The following agronomic traits were assessed: grain yield, ear yield with straw and ear yield without straw, using Griffing’s method 4. Significant effects of genotypes, environments and interaction genotypes × environments were detected for all traits. Estimates of the general combining ability led to the selection of populations P2, P4, and P5 as the ones with a higher concentration of favorable alleles for the characters evaluated. Estimates of specific combining ability and improved grain yield performance allowed P2xP3 to be selected as the most promising for production of green maize.Item Identification of populations and hybrid combinations of maize for in natura consumption(2019) Rocha, Daniel Sarto; Rovaris, Sara Regina Silvestrin; Rodrigues, Cinthia Souza; Ticelli, Marcelo; Sawazaki, Eduardo; Paterniani, Maria Elisa Ayres Guidetti ZagattoABSTRACT Brazil is one of the leading countries in the production of maize (Zea mays), with great potential for growing green maize, which has a superior commercial value in relation to maize marketed in the form of grains. Although important, the availability of cultivars recommended for the production of green maizeis still very scarce. The objectives of the present study were to estimate genetic parameters and to identify promising hybrid combinations for the development of new green maize cultivars to farmers. In the summer crop of 2016/17, ten hybrid combinations obtained through a complete diallel of five maize populations, with attributes for in natura consumption, were evaluated in two sites of the state of São Paulo, Brazil: the Instituto Agronômico(IAC) in Campinas and Tatuí. A randomized block design was used with two additional checks, with three replications, in plots with four five-meter rows spaced by 0.9 m in Campinas and 0.8 m in Tatuí, with 5 plants per meter. The following agronomic traits were assessed: grain yield, ear yield with straw and ear yield without straw, using Griffing’s method 4. Significant effects of genotypes, environments and interaction genotypes × environments were detected for all traits. Estimates of the general combining ability led to the selection of populations P2, P4, and P5 as the ones with a higher concentration of favorable alleles for the characters evaluated. Estimates of specific combining ability and improved grain yield performance allowed P2xP3 to be selected as the most promising for production of green maize.Item Identification of populations and hybrid combinations of maize for in natura consumption(2019) Rocha, Daniel Sarto; Rovaris, Sara Regina Silvestrin; Rodrigues, Cinthia Souza; Ticelli, Marcelo; Sawazaki, Eduardo; Paterniani, Maria Elisa Ayres Guidetti ZagattoABSTRACT Brazil is one of the leading countries in the production of maize (Zea mays), with great potential for growing green maize, which has a superior commercial value in relation to maize marketed in the form of grains. Although important, the availability of cultivars recommended for the production of green maizeis still very scarce. The objectives of the present study were to estimate genetic parameters and to identify promising hybrid combinations for the development of new green maize cultivars to farmers. In the summer crop of 2016/17, ten hybrid combinations obtained through a complete diallel of five maize populations, with attributes for in natura consumption, were evaluated in two sites of the state of São Paulo, Brazil: the Instituto Agronômico(IAC) in Campinas and Tatuí. A randomized block design was used with two additional checks, with three replications, in plots with four five-meter rows spaced by 0.9 m in Campinas and 0.8 m in Tatuí, with 5 plants per meter. The following agronomic traits were assessed: grain yield, ear yield with straw and ear yield without straw, using Griffing’s method 4. Significant effects of genotypes, environments and interaction genotypes × environments were detected for all traits. Estimates of the general combining ability led to the selection of populations P2, P4, and P5 as the ones with a higher concentration of favorable alleles for the characters evaluated. Estimates of specific combining ability and improved grain yield performance allowed P2xP3 to be selected as the most promising for production of green maize.Item Milho verde: avaliação da resistência à lagarta da espiga, da espessura do pericarpo e outras características agronômicas(1990) Sawazaki, Eduardo; Ishimura, Issao; Rossetto, Carlos Jorge; Maeda, Jocely Andreuccetti; Sáes, Luiz AlbertoThe varieties IAC Azteca Centenário, IAC Maya Latente, IAC-1 and IAC-VD 2 and the hybrid Cargill 742 and Agroceres 162 were evaluated for resistance to corn earworm, pericarp thickness and other agronomic characters, in a trial planted at May 1987 in the Pariquera-Açu Experimental Station, State of São Paulo, Brazil. The earworm infestation was estimated by the revised Widstrom scale and the presence of caterpillar exit holes in the husk. The kernel pericarp was measured with a comparative watch, using kernels soaked in glicerol solution and dried kernels. The other agronomic characters studied were: final stand, plant and ear height husk percentage of the ear; number, yield, total weight and medium weight of commercial ears; grain weight; and resistance to Exserohilum turcicum (Pass.) Leonard and Suggs. Except for the IAC-VD 2, all varieties were less productive than the hybrids. In relation to E. turcicum, Cargill 742, IAC Maya Latente and IAC-VD 2 were resistant Agroceres 162 was intermediated; and IAC-1 and IAC Azteca Centenário were susceptible. Similar results were obtained with the evaluation methods to lhe earworm infestation - revised Widstrom scale and presence of caterpillar exit hole in the husk. IAC Azteca Centenário and IAC Maya Latente were respectively the less and the more damage by corn earworm. Pericarp thickness was higher in the kernel side, where the differences among cultivars were also higher. Agroceres 162 and IAC Azteca Centenário had thicker pericarp. Em Pariquera-Açu, SP, em maio de 1987, foi plantado um ensaio com o objetivo de avaliar as variedades IAC Azteca Centenário, IAC Maya Latente, IAC-1 e IAC-VD 2 e dois híbridos comerciais de milho verde, Agroceres 162 e Cargill 742, quanto à resistência à lagarta da espiga, espessura do pericarpo do grão e outros caracteres de importância agronômica. O ataque da lagarta foi avaliado utilizando-se a escala modificada por Widstrom e a contagem do furo de saída da lagarta. A espessura do pericarpo, medida através de um relógio comparador, foi retirada de duas posições de grãos embebidos em solução de glicerol e de uma posição em grãos secos. Outros caracteres agronômicos estudados foram: germinação e vigor das sementes usadas; estande final; altura da planta e da espiga; porcentagem de palha na espiga; número, rendimento, peso total e peso médio das espigas comerciáveis; peso de grãos e resistência a Exserohilum turticum (Pass.) Leonard e Suggs. As variedades, com exceção da IAC-VD 2, apresentaram produção inferior aos híbridos. Quanto ao ataque do E. turcicum, o Cargill 742, IAC-VD 2 e IAC Maya Latente foram resistentes, e 'Agroceres 162', intermediário, 'IAC-1' e IAC Azteca Centenário', suscetíveis. Os resultados obtidos pelos métodos de avaliação do ataque da lagarta da espiga - a escala de Widstrom e a contagem do furo de saída - foram equivalentes na discriminação dos genótipos. A 'IAC Azteca Centenária foi a mais resistente e a IAC Maya Latente, a mais suscetível. A espessura do pericarpo variou entre os genótipos, sendo maior no 'Agroceres 162' e IAC Azteca Centenário'.