Abstract This study intends to estimate the coefficient of repeatability for traits relating to yield, so as to infer what is the minimum number of evaluations required to identify superior genotypes; to verify adaptability and stability; to predict genetic gains; and to select the best families and in S1 progenies of Psidium guajava. Families were obtained by means of self-fertilization of superior genotypes (full sibs) from the guava tree genetic breeding program of the UENF. The experiment was implemented at the Experimental Station of Ilha Barra do Pomba, in the municipality of Itaocara-RJ. In this case, an experimental randomized block design was used with 18 inbred families, three replicates, and ten plants per plot. Inbred families were evaluated in three harvests regarding fruit weight, number of fruits per plant, and total yield. It was then conducted an analysis of repeatability, adaptability, and stability of genotypes by means of the Selegen/REML/BLUP program. Repeatability values show that the performance of genotypes is constant among measurements, suggesting the need to perform only three evaluations for the selection of superior genotypes. There was agreement on the choice of families 1, 4, 6, and 12 as the most yielded, adaptable, and stable for the traits evaluated.

Resumo O presente estudo tem por objetivo estimar o coeficiente de repetibilidade das características referentes à produção da goiabeira, a fim de inferir qual o número mínimo de avaliações é necessário para identificar genótipos superiores,inalém de verificar a adaptabilidade e a estabilidade, bem como prever os ganhosgenéticos e selecionar as melhores famílias em progênies S1 de Psidium guajava. Asfamílias foram obtidas por meio de autofecundações de genótipos superiores (irmãos-completos) doprograma de melhoramento genético de goiabeiras da UENF. O experimento foi implementadona Estação Experimental da Ilha Barra do Pomba, no município de Itaocara-RJ. Odelineamento experimental utilizado foi blocos ao acaso, com 18 famílias endogâmicas, três repetições e 10 plantas por parcela. Foram avaliadas as famílias endogâmicass em trêssafras, quanto ao peso dos frutos, ao número de frutos por planta e à produção total.Posteriormente, foi realizada a análise de repetibilidade, adaptabilidade e estabilidade dosgenótipos através do programa Selegem/REML-BLUP. Os valores de repetibilidade demonstram que o desempenho dos genótipos é constante entre as medições, indicando a necessidade de apenas três avaliações para a seleção dos genótipos superiores. Houve concordância naescolha das famílias 1;4; 6 e 12 como as mais produtivas, adaptáveis e estáveis para os caracteres avaliados.

ABSTRACT The goal of our study was to evaluate the nutritional potential of dented corn hybrids for silage production. We performed a two-location trial in which 19 dented corn hybrids and five corn controls grew in four randomized blocks within two experimental areas located in the Northern (Campos dos Goytacazes) and Northwestern (Itaocara) Rio de Janeiro State, Brazil. We recorded yields of fresh and dry forage matter and yields of fresh and dry grain matter, as well as chemical composition variables. We interpreted variables by assuming a Normal distribution for yield variables and a Beta distribution for chemical composition and ratios. The SAS GLIMMIX procedure fitted the linear model under those assumptions. Dual-pool models fitted the gas production profiles generated by in vitro anaerobic fermentations. We used the nlme of R software to fit the dual-pool models and the information-theoretic approach to evaluate their quality of fit. We did a cluster analysis (NbClust of R) to group corn hybrids based on fresh and DM yields and kinetic parameters of in vitro gas production. Three clusters of corn hybrids stood out, their basic differences relied on fresh and DM yields. Nonetheless, the least-squares means for gas production characteristics among groups did not present disjoint confidence intervals. Therefore, we can infer that dented corn hybrids rank by forage yield, but not by forage quality, and recommend the most productive ones that consistently outstand in both locations (hybrids UENF-2203, UENF-2192, UENF-2193, and UENF-506-11).

Abstract This study described the main characteristics of the maize cultivars UENF MSV2210 and UENF MS2208. Adapted to the North and Northwestern regions of the state of Rio de Janeiro, they have a high agronomic performance and were developed for both silage and green maize production.

ABSTRACT. This study aimed to present the advancements in different breeding stages of super sweet corn (SS), from heterotic field corn populations to the single-cross of SS. Two parental field corn populations, four backcrossed SS populations, four SS intervarietal hybrids (SS-IH), eighteen SS single hybrids (SS-SCH) and two controls were evaluated in two environments over two crop years. The SS-IH and SS-SCH categories presented the highest ear yield, and SS-SCH presented the highest ear yield without husk (11.3 t ha-1). Although SS-SCH was the most productive category, it presented the lowest husk coverage quality. The ear yield and husk cover traits expressed the highest heterosis based on the midparents. The hybrid genotype categories (SS-SCH, SS-IH and controls) had the greatest ear length and diameter, as well as plant and ear height. It was possible to conclude that the techniques used to exploit heterosis are efficient in increasing SS yield but not husk coverage, since this trait requires productive parents. Single-crosses, such as LCSH-116 x LP8HS-129 and LCSH-116 x LP8HS-130, stood out as promising genotypes for registration since they recorded high husk coverage yield and quality.

ABSTRACT 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 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.

Abstract 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.

RESUMO O objetivo deste trabalho foi avaliar quatro índices de seleção e o método BLUP na predição de ganhos genéticos em híbridos de milho para silagem. Foram comparados quatro índices de seleção e o método BLUP na predição de ganhos genéticos. Foram avaliados 19 híbridos topcrosses, e cinco testemunhas em delineamento experimental de blocos casualizados com quatro repetições em dois ambientes, nos municípios de Campos dos Goytacazes e Itaocara - RJ, no ano agrícola 2013/2014. Avaliaram-se as características altura de plantas, altura de inserção da primeira espiga, diâmetro do colmo, produtividade de grãos no ponto de silagem e produtividade de massa verde. Para predição de ganhos foram empregados os índices de seleção de Pesek & Baker, Smith & Hazel, Mulamba & Mock e Willians, além do método BLUP. Dentre os índices de seleção avaliados, o de Mulamba & Mock proporcionou maiores magnitudes na estimativa de ganhos para a seleção dos híbridos. O método BLUP mostrou-se eficiente, selecionando híbridos com desempenho elevado e superiores aos obtidos pelos índices de seleção testados. Os híbridos UENF-2205, UENF-2208, UENF-2209 e UENF-2210, foram os que apresentaram melhor desempenho indicando elevado potencial dos híbridos dentado para produção de silagem na região Norte e Noroeste Fluminense.

ABSTRACT The objective of this study was to evaluate four selection indexes and best linear unbiased prediction (BLUP) for predicting genetic gain in maize hybrids used for silage. The genetic gain was compared between four selection indexes and BLUP. Nineteen topcross hybrids and five controls were evaluated using a completely randomized block design with four replicates in two areas located in Campos dos Goytacazes and Itaocara, Rio de Janeiro, Brazil, in the growing season 2013-2014. Plant height, first ear height, average stem diameter, grain yield at the silage stage, and green mass yield were evaluated. The genetic gain was predicted using the selection indexes proposed by Pesek and Baker, Smith and Hazel, Mulamba and Mock, Willians, and BLUP. The index of Mulamba and Mock provided higher gain estimates for selecting hybrids. BLUP was efficient and selected hybrids with higher performance than hybrids obtained using the four selection indexes. Hybrids UENF-2205, UENF-2208, UENF-2209, and UENF-2210 presented better performance, indicating the high potential of these dent hybrids for silage production in the north and northwest regions of Rio de Janeiro.

ABSTRACT 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 super-sweet 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 short_textrandomized block design (RBD)short_text 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 such as ear diameter and useful short_textearshort_text length contributed the most to increase short_textearshort_text yield (without husk); the variable ear diameter stood out for having stronger direct effect on ear yield, as well as for presenting high heritability (0.95). The trait number of grains per ear row contributed the most to the variation between hybrids, whereas the trait useful ear length contributed the least. The canonical variables showed that the genetic backgrounds of sh2-gene donor populations had effect on recurrent populations, even after five backcrossing cycles, thus resulting in the formation of two divergent groups.

ABSTRACT 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 highest correlation estimates were found between the variables ear yield without straw and grain yield, and between ear yield with straw and ear yield without straw, with magnitudes 0.95 and 0.92, respectively. The coefficient of determination was high, which indicates that the assessed components explain most of the existing variation in fresh matter yield. According to the path analysis, the trait showing the strongest direct effect on fresh matter yield was the ear yield with straw at silage maturity, in association with the high correlation (r = 0.91), which showed the possibility of achieving significant gains through indirect selection.

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.

Corn is among the most cultivated and used cereals worldwide. The objective of this study was to survey the weed community in corn cultivated in monoculture and intercropped with different Fabaceae in different management systems, during the spring/summer seasons in 2011/2012. The following treatments were evaluated: corn alone with NPK at sowing and weeding; corn alone without NPK at sowing and weeding; corn alone with NPK at sowing without weeding; corn with Mucuna aterrima; corn with Crotalaria juncea; corn with Canavalia ensiformis. Weeding increased the Importance Value Index (IVI) of Sorghum arundinaceum in monoculture, whereas fertilization promoted efficient control of Alternanthera tenella colla. The intercrop with velvet bean favored the increase of Rottboelia exaltata IVI, while the intercrop with Crotalaria juncea favored Sorghum arundinaceum. Corn plants in monoculture had the highest height (ALM) and dry weight (PMSM). However, the monoculture had the highest weed height (ALPD) and highest dry matter of narrow leaf weeds (PMSPDE). Weeding in monoculture increased ALM and PMSM, despite also increasing ALPD and PMSPDE. Monoculture with NPK fertilizer at sowing showed lower ALPD than the treatment without complete fertilization; however, PMSPDE increased with fertilization. The NPK fertilizer at sowing in monoculture increased PMSM. The intercrop of corn with Mucuna aterrima had similar effect on the variables analyzed in comparison with the other intercrop evaluated. The intercrops of corn with Crotalaria juncea and corn with Canavalia ensiformis also had similar effects on the variables analyzed.