During the dry season, the production of pastures is decreased, making farmers necessary to use corn silage as roughage source. Maize is increasingly recommended as the most important silage crop due to their qualitative and quantitative traits on top of the great acceptance for most animals. This work aimed to evaluate, through selection indices, the agronomic performance and prediction of genetic gains in corn hybrids for silage production. Eight topcross hybrids and seven controls were assessed in randomized blocks with six replications in two environments, in the municipalities of Campos dos Goytacazes and Itaocara -RJ, respectively, in the 2015/2016 agricultural year. The following agronomic traits were assessed: plant height (PH), height of first ear insertion (TH), stem diameter (CD), number of ears (NT), yield of ear with straw and ready for silage (TPS); yield of ear without straw and ready for silage (TPWS

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During the dry season the production of pastures dicreases. Usually, it makes the situation necessary to use corn silage as fibrous fodder source. The aim of this study was to develop corn hybrids for silage production, prioritizing hybrid combinations of the heterotic group 'DENT' to better understand the association between the evaluated traits and to optimize the selection process by using selection indices. Nineteen topcross hybrids and five controls were evaluated in a complete randomized block design with four and five replications in the agricultural years of 2013 and 2014. The following traits were evaluated: plant height, first ear height, stem diameter, yield at silage stage, ear yield with and without straw at silage stage, fresh mass yield, and proportion of grains in the fresh mass. The highest coefficients of correlation were obtained between yield and ear yield with straw (r = 0.94**), and between ear yield with straw and fresh mass yield (r = 0.89**). The Mulamba & Mock selection index was used for prediction of genetic gains. For selection of the superior hybrids, the index resulted in higher estimates of predicted gains for yield at silage stage and fresh mass yield, with values of 6.13 and 4.46%, respectively, using weights assigned. The use of selection indices allows simultaneous prediction of gains in the two main traits. Topcross hybrids presented high potential for silage yield in the North and Northwest Regions.

The aim of the current study is to estimate the correlation coefficients and the consequence of genotypic correlations on direct and indirect effects through path analysis between agronomic traits of maize hybrids used for silage production. Eight (8) topcross hybrids and seven (7) checks were analyzed in completely randomized blocks, with six replications, in two environments: Campos do Goytacazes and Itaocara counties-Rio de Janeiro State, in the crop year 2015/2016. The following agronomic traits were assessed: plant height, first ear height, culm diameter, number of ears, ear yield with straw at silage maturity, ear yield without straw at silage maturity, grain yield at silage maturity, grains ratio in the fresh matter and fresh matter yield.

The aim of this study is to assess whether there is linear dependence between groups of morphoagronomic and bromatological traits in hybrid silage corn. Nineteen topcross hybrids and five checks were assessed in two different environments in Campos dos Goytacazes and Itaocara counties, Rio de Janeiro State, during the growing seasons 2013/2014. The study followed a randomized blocks design with four replicates. The phenotypic and canonical correlations between the groups of seven morphoagronomic and five bromatological traits were PLANT BREEDING -Article assessed. There is linear dependence between the group pairs of morphoagronomic, and bromatological variables. The morphoagronomic trait green mass yield can be adopted in indirect selection processes to indicate the increased bromatological quality of maize silage based on features such as crude protein, neutral detergent fiber, lignin, crude fat and mineral matter. Topcross hybrids UENF-2208 and UENF-2209 presented high potential for silage yield in the North and Northwest Regions.

O milho está entre os cereais mais cultivados e utilizados pela população mundial. Com o objetivo de efetuar o levantamento da comunidade de plantas daninhas no cultivo de milho em monocultivo e em consórcio, com diferentes Fabaceae, cultivado sob diferentes manejos, este trabalho foi realizado durante o período da primavera/verão de 2011/2012. Avaliaram-se os tratamentos: milho em monocultivo com adubação NPK na semeadura e com capina, milho em monocultivo sem adubação NPK na semeadura e com capina, milho em monocultivo com adubação NPK na semeadura sem capina, milho + mucu-preta, milho + crotalária e milho + feijão-de-porco. A capina aumenta o Índice de Valor de Importância (IVI) do falso massambará (Sorghum arundinaceum) no monocultivo, enquanto para o apaga-fogo (Alternanthera tenella colla) a adubação promove controle eficiente. O consórcio com a mucuna preta favorece o aumento do IVI do camalote (Rottboelia exaltata), já o consórcio com a crotalária favorece o falso massambará (Sorghum arundinaceum). As plantas de milho em monocultivo apresentaram maior altura (ALM) e peso de matéria seca (PMSM). Contudo, o monocultivo proporcionou plantas daninhas mais altas (ALPD), além de maiores no peso da matéria seca de plantas daninhas de folhas estreitas (PMSPDE). A capina no monocultivo elevou a ALM e o PMSM, apesar de elevar também a ALPD e o PMSPDE. O monocultivo com adubação com NPK na semeadura apresenta ALPD menor que o sem adubação completa; entretanto, o PMSPDE aumentou com a adubação. A adubação com NPK na semeadura no monocultivo eleva o PMSM. O consórcio do milho com a mucuna preta apresenta efeito semelhante sobre as variáveis analisadas em comparação aos outros consórcios avaliados, assim como os consórcios do milho com a crotalária e do milho com o feijão-de-porco apresentam efeitos semelhantes sobre as variáveis analisadas.

The aim of the present study was to investigate relations among ten traits in super-sweet corn genotypes assessed by means of simple correlation, path and canonical variable analyses, as well as to investigate the relative importance of such traits to the supersweet corn breeding program developed at Darcy Ribeiro Northern Fluminense State University in order to develop strategies able to improve the efficiency in the selection of superior genotypes. Thus, trials comprising 3 × 6 partial diallel of super-sweet (sh2) corn were carried out, according to a randomized block design (RBD) with four repetitions, in two different environments located in Northern Rio de Janeiro State, Brazil (Itaocara and Campos dos Goytacazes counties). The correlation study showed that traits

The purpose of this study was to describe the main traits of the super-sweet maize cultivars 'UENF SD 08' and 'UENF SD 09', which produced higher yields than the control cultivar in the VCU (Value for Cultivation and Use) test series and proved to be competitive under the agro-climatic conditions of Northern and Northwestern Rio de Janeiro State.