Objetivou-se com este trabalho, avaliar os efeitos do fubá de milho e da casca de soja na silagem de Pennisetum purpureum cv. Roxo Botucatu. Utilizou-se um delineamento inteiramente casualizado, em esquema de parcela subdividida, com sete tratamentos (capim-elefante puro, casca de soja (5 e 10%) e fubá de milho (5 e 10%) de forma isolada ou conjunta em mesmas proporções totalizando 5 e 10%), três tempos de abertura e três repetições. Foram utilizados silos experimentais constituídos de baldes plásticos de 20 L com tampa. Os silos foram abertos aos 7, 14 e 28 dias após a ensilagem, sendo avaliadas as perdas por efluentes, matéria seca, pH, acidez titulável e a estabilidade aeróbia da massa ensilada. A utilização de aditivos na ensilagem reduziu as perdas por efluentes. A matéria seca variou com a utilização de aditivos, obtendo valores mais elevados na silagem com 10% de casca de soja ou fubá de milho, em relação à silagem de capim-elefante puro. Os resultados de pH apresentaram interação entre os tratamentos e tempo de abertura, havendo valores desejados aos 7º dia após a ensilagem. A quebra da estabilidade aeróbia ocorreu 48h após a abertura do silo para os tratamentos contendo fubá de milho individual ou em conjunto com casca de soja para os dois níveis. A utilização de fubá de milho, seja individualmente ou em conjunto com a casca de soja, foi eficiente na melhoria do padrão fermentativo da silagem de capim elefante, entretanto, cuidados adicionais devem ser tomados quanto ao manejo pós-abertura do silo.

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This study aimed to assess the effect of genetic diversity on physiological quality of soybean seeds stored in cold chamber and under environmental conditions. Ten cultivars were assessed in a randomized factorial design (2x10). Factor 1 corresponded to two storage conditions and factor 2 to ten soybean cultivars, with four replications. The evaluated variables were total germination (G%), first count of germination (F%), percentage of abnormal seedlings (AS%), germination speed index (GSI), water content (WC), electrical conductivity (EC), dry matter of seedlings (DMS) and length of seedlings (LS). Data underwent ANOVA, followed by Scott Knott test, as well as multivariate analysis of genetic diversity. The results showed a higher physiological quality for seeds under cold storage. Half of the cultivars (FPS Júpiter, FPS Urano, FPS Antares, FPS Netuno and CD 250) presented high germination rates and seed vigor, being thus indicated as high-standard materials for further breeding programs. Besides that, storage environment had influence on the clustering of soybean cultivars. Moreover, cultivars had genetic dissimilarity for almost all assessed traits as G%, GSI, F%, AS%, EC, DMS and LS.

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The identification of divergence among cultivars adapted to specific soil and climatic conditions is of fundamental importance for the realization of promising hybridizations. This diversity can be accessed through phenotypic characteristics and molecular markers. In this sense, the objective of this study was to evaluate genetic diversity of soybean cultivars in the summer and winter from agromorphological traits and molecular markers. Two experiments were conducted, one in the summer (2011) and another in the winter (2012). The experiments were conducted in a randomized block design with four replications. Six widely grown cultivars were used and they showed striking differences in regards to morphological markers. The cultivars are: M 7211 RR, TMG 123 RR, TMG 1176 RR, M 7908 RR, TMG 127 RR and TMG 7188 RR. During the development of the plant, as well after harvesting were evaluated 18 traits. The DNA of six cultivars was amplified with 16 primers (microsatellite markers) flanking microsatellite regions in soybean located in sixteen of the twenty soybean linkage groups. Genetic dissimilarity between cultivars from agromorphological traits varies depending on the growing season. The molecular markers showed genetic variability between cultivars with different results for clusters formed from the agronomic characters. Thus, both phenotypic and the molecular data proved to beinformative tools to characterize the existing conflict between soybean cultivars.

O consórcio de culturas consiste na semeadura de duas ou mais espécies na mesma área, de modo que uma das espécies conviva com a outra, em todo ou em pelo menos parte de seu ciclo. O objetivo deste trabalho foi avaliar a produção de grãos e vagens e seus componentes, das culturas de girassol, feijão-de-corda e amendoim. O estudo foi conduzido no período de abril a julho de 2010 em Quixadá-Ceará, Brasil. O delineamento utilizado foi o de blocos ao acaso constando de 9 tratamentos e quatro repetições. Os tratamentos consistiram do T1-GI100%, T2-FE100%, T3-AM100%, T4-GI75% + FE25%; T5-GI50% + FE50%; T6-GI25% + FE75%; T7-GI75% + AM25%: T8-GI50% + AM50%; T9-GI25% + AM75%. Os rendimentos das culturas em monocultivo estudadas foram superiores aos consórcios. No consórcio com feijão-de-corda a maior produção de aquênios de girassol ocorreu na associação 75% girassol + 25% feijão-de-corda. Os sistemas de consórcio apresentaram o uso eficiente da terra superior a 1 (um) nas proporções de população de plantas GI75%+FE25%, GI50%+FE50%, GI75%+AM25% e GI25%+AM75%, significando vantagem nos diferentes arranjos do consórcio sobre o monocultivo.

Soybean yield depends on photosynthesis generated by leaves, so any factor that interferes with their leaf area could affect the yield. Among these, defoliating insect attacks cause significant decreases in yield by its direct reduction of the leaf area, thereby reducing the total photosynthesis of the plant. The agronomic traits of cultivars can influence the tolerance level of the plant to this kind of stress, if it is continuous. Thus, the aim of this work was to evaluate the effect of continuous defoliation in vegetative and reproductive stages in soybean cultivars with different traits. The research was carried out in an experimental randomized complete block design in a 2×5×6 factorial scheme with four replications. Factors consisted of defoliation stages (vegetative and reproductive), defoliation levels (0, 16.7, 33.3, 66.6 and 100%) and cultivars (M 7211 RR, TMG 123 RR, TMG 1176 RR, M 7908 RR, TMG 127 RR, TMG 7188 RR). The following variables were evaluated: number of pods/plant, number of seed/plant, 100-seed weight and seed yield/plant. From the obtained results, it was observed that defoliation has a negative effect on all cultivars yield components with greater decrease when it occurs in the reproductive stage. Continuous defoliation from 16% in both the vegetative and reproductive stage significantly decreases the soybean yield. Regardless of agronomic characteristics such as growth type, maturity group and leaf shape, the effect of stress by defoliation in soybean cultivars is similar.