Desempenho agronômico de cultivares modernas de soja em ensaios multiambientes

The objective of this work was to evaluate the productive performance, and the adaptability and stability parameters of modern soybean (Glycine max) cultivars in multi-environment trials, as well as to identify the ideal genotypes for eight growing environments in Brazil. A randomized complete block experimental design was carried out, with three replicates, for the evaluation of 46 soybean cultivars in eight environments, in the microregions of adaptation 102, 201, and 202, in the 2014/2015 crop season. A complex genotype x environment interaction occurred, with changes in the ranking of genotypes among locations. The NA 5909 RG, M6410IPRO, NS 5959 IPRO, NS6823RR, M5917IPRO, NS 6767 RR, and 6563RSF IPRO cultivars showed the highest mean yields. The NA 5909 RG, NS6823RR, M6410IPRO, and NS 5959 IPRO cultivars showed high adaptability and stability and high grain yield, in the evaluated environments, and were ranked next to the ideal genotype for the analyzed environments. There are modern soybean cultivars, which are adapted, stable, and highly productive, for cultivation in the microregions 102, 201, and 202 for soybean crop adaptation in Brazil.O objetivo deste trabalho foi avaliar o desempenho produtivo, a adaptabilidade e a estabilidade de cultivares modernas de soja (Glycine max), em ensaios multiambientes, assim como identificar os genótipos ideais para oito ambientes de cultivo no Brasil. Utilizou-se um delineamento experimental de blocos ao acaso, com três repetições, para a avaliação de 46 cultivares em oito ambientes, nas microrregiões de adaptação 102, 201 e 202, na safra 2014/2015. Ocorreu interação genótipo x ambiente complexa, com alterações do ranqueamento de cultivares entre os locais. As cultivares NA 5909 RG, M6410IPRO, NS 5959 IPRO, NS6823RR, M5917IPRO, NS 6767 RR e 6563RSF IPRO apresentaram as maiores médias produtivas. As cultivares NA 5909 RG, NS6823RR, M6410IPRO e NS 5959 IPRO apresentaram elevada adaptabilidade e estabilidade e alta produtividade de grãos, nos ambientes avaliados, e posicionaram-se próximo do que seria considerado ideal para os ambientes analisados. Há cultivares modernas de soja adaptadas, estáveis e com elevada produtividade, para o cultivo nas microrregiões 102, 201 e 202 de adaptação da cultura da soja no Brasil

Eficiência de uso de nitrogênio em cultivares de trigo pioneiras e modernas

The objective of this work was to characterize Brazilian wheat cultivars, developed in different decades, as to their nitrogen use efficiency, under different availabilities of the nutrient. Ten wheat cultivars, released between 1940 and 2009, were subjected to four nitrogen fertilization rates (0, 60, 120, and 180 kg ha‑1 N), under a controlled environment, in a randomized complete block design, with three replicates. Grain yield increased in 0.54, 0.74, 0.74, and 0.82% per year at the rates of 0, 60, 120, and 180 kg ha‑1 N, respectively. Nitrogen uptake and utilization efficiencies were positively associated with N use efficiency, with strengthening relation under high N availability conditions. Modern cultivars are more efficient in N use and tolerate lower rates of the nutrient in comparison to pioneer cultivars. For the development of more efficient cultivars in N use, wheat‑breeding programs should prioritize the selection of genotypes with higher N uptake, remobilization, and utilization efficiencies.O objetivo deste trabalho foi caracterizar cultivares brasileiras de trigo, desenvolvidas em diferentes décadas, quanto à eficiência de uso de N, sob diferentes disponibilidades do nutriente. Dez cultivares de trigo, lançadas entre 1940 e 2009, foram submetidas a quatro doses de adubação nitrogenada (0, 60, 120 e 180 kg ha‑1 de N), em ambiente controlado, em delineamento de blocos ao acaso, com três repetições. A produtividade de grãos aumentou em 0,54, 0,74, 0,74 e 0,82% ao ano, nas doses de 0, 60, 120 e 180 kg ha‑1 de N, respectivamente. As eficiências de absorção e de utilização de N estiveram positivamente associadas à eficiência de uso do nitrogênio, com estreitamento na relação em condições de alta disponibilidade de N. As cultivares modernas são mais eficientes no uso do N e toleram doses mais baixas do nutriente, em comparação às cultivares pioneiras. Para o desenvolvimento de cultivares mais eficientes no uso de N, os programas de melhoramento genético de trigo devem priorizar a seleção de genótipos com maiores eficiências de absorção, remobilização e utilização de N

Agronomic performance of soybean genotypes and local identification for conducting multi-environment trials in southern Brazil

Productivity increases in soybean crop over the years are the result of the constant efforts of breeding programs to provide more productive and adapted cultivars to producers. Each year hundreds of strains are evaluated in multi-environment trials by breeding programs to identify the genotypes best suited to each region of interest. In this sense, knowing the adaptability and stability of the genotypes in each target region, as well as, the best test sites, are fundamental for the increments of crop productivity. Thus, the objective of this work was to identify the best test sites for conducting multi-environment trials for soybean in southern Brazil, as well as to identify the best soybean genotypes for each region and edaphoclimatic cultivation. Data from cultivation and use value (VCU) trials conducted between the 2012-13 and 2016-17 harvests were used. All assays were conducted in a randomized complete block design with three replicates. The statistical analyzes were performed with the GGEBiplot software. The best venues for conducting VCU trials are: Macroregion 01, REC 101: Cachoeira do Sul; REC 102: Ronda Alta, Passo Fundo, Santa Bárbara do Sul and Ciríaco; and REC 103: Castro. Macroregion 02, REC 201: Rolândia, Marechal Cândino Rondon, Campo Mourão, Santa Terezinha de Itaipu, Palotina, Floresta and Londrina; REC 202: Navirai; and REC 204: Ponta Porã and Maracajú. The genotypes closest to the ideal were: Macroregion 01, REC 102: genotype 68I70RSF IPRO; REC 103: 54I52RSF IPRO and NS 5959 IPRO genotypes. Macroregion 02, REC 201: Genotype 63I64RSF IPRO, REC 204: genotypes 7166RSF IPRO, 63I64RSF IPRO and M6210IPRO. The 68I70RSF IPRO genotype presented the highest RG in the Santa Bárbara do Sul and Passo Fundo sites in REC 102. In REC 103 the 54I52RSF IPRO genotype was the best in Castro and the NS 5959 IPRO genotype the best in Castro and Vacaria. In REC 201, genotype 63I64RSF IPRO showed the highest RG in the Mamborê, Marechal Cândido Rondon and Londrina sites in 2013, 2014 and 2015, respectively, and at REC 204 in Dourados, genotypes 7166RSF IPRO, 63I64RSF IPRO and M6210IPRO had the highest RG in 2013, 2014 and 2015, respectively.Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Os incrementos de produtividade na cultura da soja ao longo dos anos são resultado dos constantes esforços dos programas de melhoramento em disponibilizar cultivares mais produtivas e adaptadas aos produtores. Todos os anos, centenas de linhagens são avaliadas em ensaios multi-ambiente (MET) por programas de melhoramento, visando identificar os genótipos mais adaptados para cada região de interesse. Neste sentido, conhecer a adaptabilidade e estabilidade dos genótipos em cada região-alvo, bem como, os melhores locais de teste, são fundamentais para os incrementos de produtividade da cultura. Assim, o objetivo deste trabalho foi identificar os melhores locais de teste para a condução de MET para soja na região Sul do Brasil, bem como identificar os melhores genótipos de soja para cultivo em cada região edafoclimática (REC). Foram utilizados dados de ensaios de Valor de Cultivo e Uso (VCU), conduzidos entre as safras 2012-13 a 2016-17. Todos os ensaios foram conduzidos em delineamento de blocos ao acaso, com três repetições. As análises estatísticas foram realizadas com o software GGEbiplot. Os melhores locais para condução de ensaios de VCU são: Macrorregião 01, REC 101: Cachoeira do Sul; REC 102: Ronda Alta, Passo Fundo, Santa Bárbara do Sul e Ciríaco; e REC 103: Castro. Macrorregião 02, REC 201: Rolândia, Marechal Cândino Rondon, Campo Mourão, Santa Terezinha de Itaipu, Palotina, Floresta e Londrina; REC 202: Naviraí; e REC 204: Ponta Porã e Maracajú. Os genótipos mais próximos do ideal foram: Macrorregião 01, REC 102: 68I70RSF IPRO; REC 103: 54I52RSF IPRO e NS 5959 IPRO. Macrorregião 02, REC 201: 63I64RSF IPRO, REC 204: 7166RSF IPRO, 63I64RSF IPRO e M6210IPRO. O genótipo 68I70RSF IPRO apresentou o maior RG nos locais Santa Bárbara do Sul e Passo Fundo, na REC 102. Na REC 103 o genótipo 54I52RSF IPRO foi o melhor em Castro. Já o genótipo NS 5959 IPRO foi o melhor em Castro e Vacaria. Na REC 201, o genótipo 63I64RSF IPRO apresentou RG mais elevado nos locais Mamborê, Marechal Cândido Rondon e Londrina em 2013, 2014 e 2015, respectivamente. Na REC 204, em Dourados, os genótipos 7166RSF IPRO, 63I64RSF IPRO e M6210IPRO apresentaram o maior RG nos anos de 2013, 2014 e 2015, respectivamente

Methods of analysis and number of replicates for trials with large numbers of soybean genotypes

ABSTRACT: The aim of this study was to evaluate the experimental precision of different methods of statistical analysis for trials with large numbers of soybean genotypes, and their relationship with the number of replicates. Soybean yield data (nine trials; 324 genotypes; 46 cultivars; 278 lines; agricultural harvest of 2014/15) were used. Two of these trials were performed at the same location, side by side, forming a trial with six replicates. Each trial was analyzed by the randomized complete block, triple lattice design, and use of the Papadakis method. The selective accuracy, least significant difference, and Fasoulas differentiation index were estimated, and model assumptions were tested. The resampling method was used to study the influence of the number of replicates, by varying the number of blocks and estimating the precision measurements. The experimental precision indicators of the Papadakis method are more favorable as compared to the randomized complete block design and triple lattice. To obtain selective accuracy above the high experimental precision range in trials with 324 soybean genotypes, two repetitions can be used, and data can be analyzed using the randomized complete block design or Papadakis method

Repeatability of associations between analytical methods of adaptability, stability, and productivity in soybean

<div><p>Abstract: The objective of this work was to evaluate the association between estimates of adaptability, stability, and productivity in soybean (Glycine max), and to estimate the repeatability coefficient of these associations between years. A total of 22 genotypes were evaluated in 27 environments in the 2012/2013 crop season and in 19 environments in 2013/2014. In the next crop seasons, 28 genotypes were evaluated in 26 environments, in 2014/2015, and in 25 environments in 2015/2016, totalizing 97 trials. Fourteen methods were evaluated; Spearman correlation coefficients were obtained for the parameters of stability, adaptability, and productivity; and the repeatability coefficients, as well as the minimum number of required environments for a coefficient of determination of 80 and 90%, were calculated. The minimum number of environments required to estimate the degree of association between the parameters was low (seven sites). The methods of Eberhart & Russell and GGE biplot are essential in the evaluation of productivity, adaptability, and stability in soybean because they are able to encompass these aspects using a minimum set of methods. The methods of Annicchiarico (AN), Silva & Barreto (SB), Cruz (CR), and Storck & Vencovsky (SV) can be used to generate complementary information, such as: stability for general, favorable, and unfavorable environments (AN); adaptability in favorable and unfavorable environments (SB, CR, and SV); and average productivity in all environments and in favorable or unfavorable environments (SV).</p></div