The objective of this work was to present a methodological alternative for studies of the characterization and selection of corn (Zea mays) genotypes, through the joint analysis of variance of an augmented block design, using Scott-Knott’s test, and to present the hybrids selected from the adopted strategy, to show its efficiency. For the application of the methodology, a case study was used: the selection of superior corn hybrids for the Brazilian Cerrado. In four locations, 70 experimental hybrids were evaluated in an augmented block design without replicates, with three controls replicated once in each block. The analysis of experimental groups applied to the augmented block design, followed by genotype classifications by Scott-Knott’s multiple comparison test, is a viable alternative for studies with a low number of replicates and a large number of genotypes. Based on the tested methodology, the following experimental hybrids are selected for grain yield: HT007, HT008, HT018, HT004, HT024, HT005, and HT071.

The use of pre-harvest desiccants contributes to reducing the exposure of seeds to unfavorable climatic conditions, reducing environmental interference in their quality. But this use must be done in a way that affects, as little as possible, the agronomic behavior of the plants. The objective of this study was to evaluate the action of paraquat desiccation, applied at different reproductive stages, on the agronomic behavior of sunflower plants and the quality of its seeds. The experimental design used was randomized blocks in a factorial scheme with three repetitions. The herbicide Paraquat (2,0 L ha-1) was applied in the phases R7, R8 and R9 to plants of the cultivars BRS 323, Aguará 4 and M734. The characters evaluated were achene yield, oil content, weight of one thousand achenes, and germination. The most adequate reproductive stage for desiccation of sunflower plants with Paraquat was the R8 stage, obtaining the highest yield of achenes, oil content and weight of one thousand achenes. At this reproductive stage, there was no difference between the average germination values of sunflower achenes obtained with or without the application of the desiccant.

Stevia rebaudiana Bertoni, a semi-perennial herb from the Asteraceae family, is native to the Paraguay–Brazil border region. The growing industrial interest in this species is due to its natural sweetening properties, such as steviol and its derivatives, which offer sweetness without adding calories. Morphological traits are crucial for assessing genetic variability and ensuring distinctness, homogeneity, and stability (DHS) for cultivar protection. This study characterized 19 elite Stevia genotypes from Embrapa Cerrados’ Active Germplasm Bank (BAG) using 21 morphological descriptors from Brazil’s Ministry of Agriculture, Livestock, and Supply (MAPA). Genetic distances were calculated using the simple coincidence index complement method, and clustering was performed via the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). The results showed that 17 of the 21 descriptors (>80%) effectively differentiated the genotypes, revealing significant genetic variability. Dendrogram analysis identified at least four major similarity groups, highlighting the potential of these genotypes for Stevia breeding programs. These findings underscore the suitability of these elite genotypes for developing superior varieties adapted to Cerrado conditions, supporting future cultivation and genetic improvement efforts.

In this work, the objective was to evaluate morphoagronomic traits, correlate and select elite genotypes of Stevia rebaudiana (Bert.) Hemsley with high productivity, and adapted to Brazilian Savanna conditions. A total of 230 genotypes were evaluated, from the Embrapa Cerrados Working Collection, from 2018 to 2019, with 24 evaluations, carried out in six cuts, with each cut representing a certain moment of generation of the response data of the analyzed genotypes. Four traits were analyzed: green biomass production (g), plant height (cm), tillering number and juvenile period of each individual. The means of the characteristics of each genotype were correlated according to Pearson's correlation coefficient. The Mulamba and Mock index was applied, with a selection intensity of 10%, to choose the superior genotypes. There are high positive correlations between juvenile period, height and green biomass production. The selected population were 23 superior genotypes, based on the application of rank sum resulting in high selection gains for the traits of interest. Finally, the selection of elite stevia genotypes with high production of green biomass, greater insensitivity to length of the daily light period, as well as taller plants, are essential for the continuity of the stevia breeding program on the Brazilian Savanna.

Barley is an important crop for Brazil and an advantageous alternative for irrigated cultivation in the Brazilian Savanna. The present study aimed to characterize and estimate genetic, phenotypic, and environmental parameters and select genotypes from the Embrapa Cerrados irrigated barley working collection. The experiment was established in Randomized Blocks with four replications under irrigation in Embrapa Cerrados, Planaltina-DF. The traits evaluated were grain yield, commercial classification of first grains, 1000-seed weight, plant height, lodging, and cycle. The genetic parameters and correlations between the traits evaluated were obtained. High values of heritability, in a broad sense, were verified. The high coefficients of genotypic variance and the high selective accuracy obtained corroborate the favorable environmental condition for the selection of genotypes. It was verified that the genotypic correlations were higher than the phenotypic correlation coefficients, showing a greater contribution of genetic factors in the expression of the traits. Earlier genotypes had higher grain yields, first-class commercial classification, 1000-seed weight, and height. There was a strong positive correlation between the commercial classification of first grains and 1000-seed weight. Genotypes PFC 2005143, PFC 2006134, and PFC 2004212 were selected for use in crossbreeding blocks within the Brazilian irrigated barley breeding program.

The objective of this work was to evaluate and compare the genetic diversity of 29 barley genotypes, on the basis of molecular markers and quantitative agronomic traits, under irrigation in the Brazilian Cerrado. The randomly amplified polymorphic DNA (RAPD), inter sequence simple repeats (ISSR), and simple sequence repeat (SSR) molecular markers were used. The quantitative agronomic traits were evaluated in two irrigated environments in the Brazilian Cerrado, for the following parameters: estimated grain yield, grain size, thousand seed weight, plant height, lodging degree, and days to heading. Marker polymorphisms were 91, 51.46, and 85% for RAPD, ISSR, and SSR, respectively. The RAPD, ISSR, and SSR markers are complementary for the identification of genetic variability among barley genotypes. The low correlations between the distances estimated on the basis of molecular markers and the distances estimated on the basis of agronomic traits emphasize the importance of using complementary analyses of molecular markers for more complete studies on genetic variability. The agronomic traits of the genotypes are different in the two environments. The selected genotypes can compose the working collection of irrigated barley in the Brazilian Cerrado because of their wide genetic variability.