Abstract The greatest challenge in onion breeding programs is achieving gains from plant selection in an efficient manner. Selection indices are already in use for many species but are rare in onion. The aim of this study was to characterize the gain from selection in onion germplasm through nonparametric indices. To bring about this dynamic, four experiments were conducted with different sets of genotypes. Several agronomic characteristics were evaluated. Estimates of gains and selection of genotypes were obtained from the selection index based on rank sum, from the genotype-ideotype distance index, and from the multiplicative index. To test the efficiency of the indices used, the coefficient of coincidence was calculated. The total gains from selection were greater through use of the multiplicative index, with values of 31.84% for the advanced lines and 37.4% for the segregating genotypes. It was possible to select superior onion lines in each experiment. The coefficients of coincidence, all with values greater than 0.5, confirmed that the indices provided a margin of safety in the selection of superior genotypes.

Resumen El mayor desafío en los programas de mejoramiento de cebollas es obtener beneficios de la selección de manera satisfactoria. Los índices de selección ya se utilizan en diversas especies, pero son raros en cebolla. El objetivo de este estudio fue caracterizar la ganancia de la selección en germoplasma de cebolla a través de índices no paramétricos. Para lograr esta dinámica, se llevaron a cabo cuatro experimentos con diferentes conjuntos de genotipos. Se evaluaron varias características agronómicas. Las estimaciones de ganancias y selección de genotipos se obtuvieron a partir del índice de selección basado en la suma de rangos, del índice de distancia genotipo-ideotipo y del índice multiplicativo. Para probar la eficiencia de los índices utilizados, se calculó el coeficiente de coincidencia. Las ganancias totales de la selección fueron mayores mediante el uso del índice multiplicativo, siendo los valores de 31,84% para las líneas avanzadas y 37,4% para los genotipos segregantes. Fue posible seleccionar líneas de cebolla superiores en cada experimento. Los coeficientes de coincidencia, todos con valores superiores a 0,5, confirmaron que los índices proporcionaron un margen de seguridad en la selección de genotipos superiores.

RESUMEN El estrés hídrico en la planta es un problema importante en el bioma Cerrado de Brasil. Los períodos secos y los eventos climáticos aleatorios causan pérdidas de calidad y productividad en las plantas de maíz dulce. Compuestos como el silicio (Si), pueden ser estudiados para reducir los impactos negativos del estrés hídrico en los cultivos agrícolas. Pruebas adicionales pueden permitir a los agricultores aumentar el uso de compuestos a base de silicio. El objetivo de este trabajo fue evaluar los parámetros de producción de maíz dulce (Zea mays var. Saccharata, híbrido Tropical Plus®) con niveles de estrés hídrico y dosis de silicato de potasio aplicadas por pulverización foliar. El diseño experimental fue un diseño de bloques al azar con cuatro tensiones hídricas en el suelo (15, 30, 45 y 60 kPa) y cuatro dosis de silicato de potasio (0, 6, 12 y 24 L ha-1) en invernadero. Los factores estudiados solos o en interacción no afectaron la mayoría de los parámetros de producción de maíz dulce. Se discute la hipótesis de que estos resultados pueden haber sido parcialmente afectados por la presencia de silicio. El rendimiento de la planta de maíz dulce se vio afectado principalmente por el estrés hídrico del suelo a 60 kPa.

ABSTRACT Plant water stress is a major problem in the Cerrado biome of Brazil. Dry periods and random climatic events cause quality and yield losses in sweet corn plants. Compounds, such as silicon (Si), are being studied to reduce the negative impacts of water stress on agricultural crops. Further tests may allow farmers to increase the use of silicon-based compounds. The objective of this study was to evaluate the production parameters of the sweet corn (Zea mays var. saccharata) (Poaceae) Tropical Plus® hybrid with water stress and potassium silicate doses applied with foliar spraying. A randomized block design with four soil water tensions (15, 30, 45 and 60 kPa) and four potassium silicate doses (0, 6, 12 and 24 L ha-1) was used in a greenhouse. The studied factors, alone or in interaction with each other, did not affect most of the sweet corn yield parameters. The hypothesis that these results may have been partially affected by the presence of silicon are discussed. The sweet corn plant yield was affected mainly by the soil water tension of 60 kPa.

Foram avaliadas e selecionadas as famílias provenientes do programa de melhoramento do tomateiro da UFU, com potencial para processamento industrial e comparados seus desempenhos com os híbridos mais utilizados pelos produtores na região de Patos de Minas. O ensaio foi conduzido na EE Fazenda Barreiro da Unilever Bestfoods Brasil, em Patos de Minas. Utilizaram-se 30 famílias de tomateiro e os híbridos Heinz 9553, Heinz 7155N2 e Hypeel 108. As Parcelas constituíram-se de linhas duplas espaçadas 0,5 m entre si, com 10 m de comprimento, irrigadas por gotejamento. O espaçamento entre as linhas duplas foi de 1,3 m e a população de 27 mil plantas por hectare. O delineamento experimental foi de blocos ao acaso, com quatro repetições. A semeadura foi realizada em 19/05/01. O rendimento de polpa mostrou correlações fenotípicas e genotípicas positivas com a produção total, produção de frutos comerciais, % de sólidos solúveis totais, coloração do suco, número de frutos maduros por planta e pH e negativa com acidez total titulável. Destacaram-se a família UFU 06 e os três híbridos comerciais.

Tomato families originated from the processing tomato breeding program of the Universidade Federal de Uberlandia were evaluated and selected and compared to the performance with the most planted hybrids in Patos de Minas, Brazil. The experiment was conducted in the E. E. Barreiro, Unilever Bestfoods, in Patos de Minas. Thirty tomato families and the hybrids Heinz 9553, Heinz 7155N2 and Hypeel 108 were used. Experimental plots consisted of two lines, each one 10 m long, spaced 0,5 m from each other and irrigated with drip irrigation. The space between each double row was 1,3 m and the population of 27 thousand plants per hectare. The experimental design was a randomised complete block with four repetitions, installed on 05/19/01. The paste yield showed positive phenotypic and genotypic correlation with total fruit yield, commercial fruit yield, percentage of total soluble solids, juice coloration, number of mature fruits per plant and pH and negative correlation with the total titled acidity. Best results were observed in the family UFU 06 and in the commercial hybrids.