O objetivo deste trabalho foi determinar as capacidades geral e específica de combinação, os parâmetros genéticos e a correlação entre caracteres morfoagronômicos, em acessos de pinhão-manso (Jatropha curcas). Utilizou-se o delineamento experimental de blocos ao acaso, com três repetições. Foram avaliados os caracteres: PR, produção de sementes; AP, altura de planta; NRS, número de ramos secundários; NFF, número de flores femininas; DC, diâmetro de colo; P100, massa de 100 sementes; AR, altura de ramificação; e DCO, diâmetro de copa. A capacidade geral de combinação foi significativa para PR, NRS, DC, P100 e AR, enquanto a capacidade específica foi significativa apenas para NFF e NRS. As estimativas de herdabilidade foram superiores a 70%, em NRS, NFF, DC e AR. Observou-se correlações genotípicas positivas entre NRS e DC (0,942), NRS e AP (0,762), NRS e DCO (0,798), NRS e PR (0,759), DC e AP (0,738), DC e DCO (0,844), DC e PR (0,802), e DCO e PR (0,742); e negativas entre NRS e AR (-0,665), e DC e AR (-0,687). O NFF explicou mais de 50% da variação dos híbridos de pinhão-manso. A capacidade geral de combinação é preponderante na maioria das características avaliadas.

The objective of this work was to determine the general and the specific combining abilities, the genetic parameters, and the correlation between morphoagronomic traits in physic nut (Jatropha curcas) accessions. A randomized block experimental design, with three replicates, was used. The evaluated characters were: Y, yield; PH, plant height; NSB, number of secondary branches; NFF, number of female flowers; SD, stem diameter; W100, weight of 100 seeds; HB, height of branches; and DC, diameter of crown. The general combining ability was significant for Y, NSB, SD, W100, and HB, while the specific combining ability was signicant only for NFF and NSB. Heritability estimates were higher than 70% for NSB, NFF, SD, and HB. Positive genotypic correlations were observed between NSB and SD (0.942), NSB and PH (0.762), NSB and DC (0.798), NSB and Y (0.759), SD and PH (0.738), SD and DC (0.844), SD and Y (0.802), and DC and Y (0.742); and negative ones between NSB and HB (-0.665), and SD and HB (-0.687). The NFF explained over 50% of the variation in the physic nut hybrids. General combining ability preponderates on the evaluated traits.

Three experiments were conducted to determine the nutritional requirements of potassium (K) for male Ross broiler chickens, from 8 to 21, 22 to 42 and 43 to 53 days of age. The following parameters were evaluated: body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). In each experiment, a completely randomized experimental design was used, with six treatments (K levels), and six, eight and eight numbers of replicates, and eight, five and four birds per pen, respectively. The experimental diets were basal diets deficient in K but supplemented with K carbonate to result in levels of 0.30, 0.44, 0.58, 0.72, 0.86 and 1.00% K. Estimated requirements for BWG were 0.628, 0.714 and 0.798% K, for the periods 8-21, 22-42 and 43-53 d, respectively.