Aims: The research was carried out to evaluate the agronomic performance of corn cultivars in contrasting phosphorus environments in the state of Pará, Brazil. Study Design: The experimental design was randomized blocks with ten treatments and three replications. The treatments were composed of ten cultivars: AG 1051, AG 8088PRO2, BR 206, BRS 3046, PR 27D28, 2B655PW, AL BANDEIRANTE, ANHEMBI, CATIVERDE 02 and ORION Place and Duration of Study: In the 2017/18 crop, two competition trials of corn cultivars were carried out at Sítio Vitória, municipality of Santa Maria das Barreiras, state Pará, Brazil. Methodology: Two competition trials of corn (Zea mays L.) cultivars were carried out under contracting conditions of phosphorus: high P (100 kg ha-1 of P2O5) and low P (50 kg ha-1 of P2O5), using simple superphosphate (18% P2O5) as the source. The agronomic efficiency of phosphorus use was obtained by the difference between grain yield in both levels, divided by the difference between doses. The variables evaluated were: ear height, plant height, ear diameter, number of rows per year, number of grains per rows and grain yield. Results: The mean grain yield of the cultivars ranged from 5,446 kg ha-1 (low P) to 11,486 kg ha-1 (high P), and the means of all cultivars were higher in high P. The means agronomic efficiency ranged from 25.1 kg kg-1 (AL BANDEIRANTE) to 96.6 kg kg-1 (AG 1051). Conclusion: The highest phosphorus dose (100 kg ha-1 of P2O5) resulted in higher values in the variables studied. The cultivars that stood out the most, under high and low phosphorus, were AG 8088PRO2, AG 1051 and BRS 3046, the last two being agronomically efficient.

Revisão às cegas por pares ABSTRACTThis study aimed to study the correlation between different environments of genetic diversity in corn genotypes in the city of Palmas, Tocantins, in late planting. The tests were divided into two planting dates (01.21.2014 and 02.19.2014). In each time the tests were performed under conditions of high nitrogen (N), mean N and low N in topdressing, yielding 6 environments. The experimental design used in each test was a randomized complete block design with three replications and 12 treatments (genotypes) of corn coming from the. Sixteen agronomic traits were used. Was conducted study of genetic diversity for each test, all tests together and combinations thereof. Significant effects were detected for the correlations in 30% of the pairs. In AMB 1, there was a positive and significant correlation for the great majority of combinations, which showed a possibility in reducing the number of experiments to study diversity. And the nonsignificance of the correlation between periods 1 (AMB 2) and season 2 (AMB 3), exemplifies the need to conduct trials at different times.

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e of this study was to evaluate the agronomic performance of corn cultivars for grain production in the south at low altitude in the Cerrado-Amazon ecotone. Place: The research was carried out at Sítio Vitória (8°18'32.0"S, 50°36'58.0"W, 278 MASL), in the south of the state of Pará, Brazil. Study Design: The experimental design was randomized blocks with twelve treatments and three replications. The treatments were eight corn hybrids: AG 1051, AG 8088, BM 3051, BR 2022, BR 205, BR 206, BRS 3046 and PR 27D28; and four open pollination populations: AL BANDEIRANTE, ANHEMBI, CATIVERDE and M 274. Methodology: Sowed on January 28, 2019. The following characteristics were evaluated: ear height, plant height, number of grains per row, ear diameter, ear length, ear weight and grain yield. Results: The cultivars showed a difference for all traits. The grain yield of the cultivars ranged from 4,567 kg ha-1 (BR 205) to 9,450 kg ha-1 (AG 1051). Conclusion: The hybrids AG 1051 and BM 3051 were the ones that stood out the most, had the best performance in the Cerrado-Amazon ecotone.

Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição 4.0 Internacional (CC BY 4.0).O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.