The objective of this work is to study the agronomic performance and genetic divergence in corn in the Cerrado-Amazon ecotone. The trials were conducted in the 2017/18 harvest at a property in the state of Pará. The experimental design was a randomized block with nine treatments and three replications, where the treatments are represented by nine cultivars of corn. The characteristics to evaluate agronomic performance and genetic divergence were: ear height (cm), plant height (cm), ear length (cm), ear diameter (mm), number of rows, number of grains per row and grain yield (kg ha−1). The cultivars were separated into a multivariate model in five groups using the Tocher optimization method. The cultivar AG 1051 showed the best agronomic performance. The results of genetic divergence were according to the generalized distance of Mahalanobis (D2), with the commences AG 8088 x CATIVERDE and AG 1051 x AL BANDEIRANTE, the most promising for future crosses.

Corn is of great importance in the national economy, being one of the most produced and exported cereals in Brazil. With the growing concern of producing food for the population, the search for new corn genotypes is increasingly intensified in order to obtain efficient seeds with an adequate response to the particularities of each planting region. In this sense, the present work aims to identify genotypes of corn efficient and responsive to the use of nitrogen for grain production in the Cerrado biome. The studies were carried out in two maize trials at the

The genetic divergence in maize populations is important, as it allows us to identify among the existing genotypes, the best ones to be used as parents in future breeding programs as a strategy for obtaining greater gains. Therefore, the objective of this work was to estimate the genetic divergences in green corn cultivars. The tests were conducted in the 2019/20 harvest on a property in the state of Pará. The design used in the given experiment was randomized blocks (DBC) and 3 replicates. The experimental plot consisted of 4 rows of 5.0 m spaced at 0.9 m between rows, the two central rows being considered the useful area. The genetic divergence was evaluated by multivariate procedures such as the generalized Mahalanobis distance and by Tocher optimization grouping methods and Singh criterion to quantify the relative contribution of the seven characteristics. The characteristics average mass of grains per ear and number of grains in the row of the ear were the ones that most contributed to genetic divergence. The dual hybrids BR205 and BRS3046 and the triple hybrid AG8088 are potentially promising for use in future breeding programs.The sweet corn harvest is carried out when the grains are still high in moisture (greater than 70%), which highlights the interference of the physiological stage of grain maturity in the yield. Therefore, the most propitious time for harvesting is the period in which the grains reach Débora Thaís da Silva Coutas et al.

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.

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