Wood is the main source of energy in the energy matrix of underdeveloped countries, in addition to having a significant participation in developing countries, ranking fourth in Brazil. Thus, this study aimed to determine a model for determining the energy density of forest species from the Cerrado. Samples of trunks and branches were collected from 34 forest species in an area of 10.15 ha located in the Cerrado region aiming for immediate analysis, i.e. the contents of ashes (ASH), volatile matter (VM), fixed carbon (FC), and higher calorific value (HCV). Data from dry and saturated mass were obtained in order to determine the basic density. The species presented values of VM ranging from 77 to 85.5%, ASH from 0 to 1%, FC from 14 to 23%, and HCV ranging from 18,282 to 20,121 GJ ton-1. A significant relationship was found between VM and FC (R2 = 0.9927) whereas no significant values were found between HCV and basic density. The average value of energy density considering the 34 species was 12,459 Mcal m-3. The estimated energy density of the area was 1,378,541 Mcal ha-1. The proposed model for calculating the energy density as a function of basic density favors energy surveys of areas to be explored since there is no need for calorific value analysis.

RESUMO A madeira é a principal fonte de energia na matriz energética dos países subdesenvolvidos e nos países em desenvolvimento a participação é significativa, ocupando o quarto lugar no Brasil. Sendo assim, o objetivo desse trabalho foi determinar um modelo para determinação da densidade energética de espécies arbóreas do Cerrado. As amostras foram coletadas de árvores em uma área de cerrado de 10,15 hectares. Foram coletadas amostras de tronco e galhos de 34 espécies florestais para análise imediata (cinzas, material volátil, carbono fixo) e poder calorífico superior. Dados de massa seca e massa saturada foram obtidos para a determinação da densidade básica. As espécies apresentaram valores de teor de material volátil entre 77% e 85,5%, teor de cinzas entre 0 e 1% , teor de carbono fixo entre 14% e 23% . O poder calorífico superior ficou entre 18.282 GJ/ton e 20.121 GJ/ton. Quando testadas as relações entre as variáveis da análise imediata (MV, CZ e CF), e o poder calorífico superior (PCS), foi encontrada relação significativa entre MV e CF (R2 = 0.9927), enquanto o poder calorífico superior e a densidade básica das espécies não apresentaram relação significativa. O valor médio da densidade energética para as 34 espécies foi de 12.459 Mcal.m-3. A estimativa da densidade energética da área foi de 1.378.541 Mcal/ha. O modelo proposto para o cálculo de densidade energética em função da densidade básica facilita os levantamentos energéticos de áreas a serem exploradas, pois não há necessidade da análise de poder calorífico. | ABSTRACT Wood is the main source of energy in the energy matrix of underdeveloped countries, in addition to having a significant participation in developing countries, ranking fourth in Brazil. Thus, this study aimed to determine a model for determining the energy density of forest species from the Cerrado. Samples of trunks and branches were collected from 34 forest species in an area of 10.15 ha located in the Cerrado region aiming for immediate analysis, i.e. the contents of ashes (ASH), volatile matter (VM), fixed carbon (FC), and higher calorific value (HCV). Data from dry and saturated mass were obtained in order to determine the basic density. The species presented values of VM ranging from 77 to 85.5%, ASH from 0 to 1%, FC from 14 to 23%, and HCV ranging from 18,282 to 20,121 GJ ton-1. A significant relationship was found between VM and FC (R2 = 0.9927) whereas no significant values were found between HCV and basic density. The average value of energy density considering the 34 species was 12,459 Mcal m-3. The estimated energy density of the area was 1,378,541 Mcal ha-1. The proposed model for calculating the energy density as a function of basic density favors energy surveys of areas to be explored since there is no need for calorific value analysis.

Agronomic responses to the use of agricultural inputs have been used in agriculture to identify the optimal level of nutrients to be supplied for high yield. This strategy helps to avoid economic losses and excessive application of fertilizers that has caused pollution of aquifers and soil degradation. The aim of the study was to evaluate water use efficiency, agronomic efficiency of nitrogen, heat units and use of evapotranspiration in yield and its components in sunflowers under hot climate conditions in function of nitrogen fertilizer application during two sowing season. The experiment was conducted in the field. The treatments were two sowing seasons and three levels of nitrogen fertilizer application and one control: 0, 60, 80 and 120 kg N ha-1. The nitrogen source was urea. The experimental design was complete random blocks with factorial array and four replications. The occurrence of cv. Cobalto sunflower phenological stages were not modified by the treatments. Urea favored agronomic efficiency and water use efficiency. Yield components were modified positively, with increasing receptacle area, 100-grain weight, and grain yield per receptacle. Application of nitrogen fertilizer favored sunflower development, although environmental conditions are of critical importance as demonstrated by a clear interaction between the yield response to fertilizer application and the environment where the plants grew.

RESUMO As respostas agronómicas ao uso dos insumos agrícolas, têm sido usados na agricultura para identificar o nível óptimo de fornecimento de nutrimentos para um alto rendimento, estratégia que ajuda a evitar perdas económicas, e a evitar o excessivo aplicativo de fertilizantes que têm provocado contaminação de mantos acuíferos e degradação do solos. O objetivo do estudo foi avaliar a eficiência no uso da água, eficiência agronômica do nitrogênio, unidades calor e uso da evapotranspiração no rendimento e componentes do rendimento de girassol em condições quentes em duas épocas de cultivo em função da fertilização de nitrógeno. Foi realizada no campo em condições experimentais. Os tratamentos consistiram em duas épocas e três níveis de aplicação de fertilização nitrogenada e um controle de 0, 60 80 e 120 kg N ha-1, sendo usado como fonte de nitrogênio uréia. O delineamento experimental foi blocos completos randomizados, com arranjo fatorial e quatro repetições. A ocorrência de estádios fenológicos em cv de girassol. O cobalto não foi modificado pela aplicação de tratamentos. A aplicação de uréia, favoreceu a eficiência agronômica e eficiência no uso da água, modificou positivamente os componentes do rendimento aumentando a área do capítulo, o peso de 100 grãos e o rendimento de grãos por capítulo. A adubação nitrogenada se manifestou em favor do girassol, embora as condições ambientais sejam de importância crítica, como demonstrado em uma clara interação entre a resposta ao rendimento e a fertilização e o ambiente onde foi desenvolvido. | ABSTRACT Agronomic responses to the use of agricultural inputs have been used in agriculture to identify the optimal level of nutrients to be supplied for high yield. This strategy helps to avoid economic losses and excessive application of fertilizers that has caused pollution of aquifers and soil degradation. The aim of the study was to evaluate water use efficiency, agronomic efficiency of nitrogen, heat units and use of evapotranspiration in yield and its components in sunflowers under hot climate conditions in function of nitrogen fertilizer application during two sowing season. The experiment was conducted in the field. The treatments were two sowing seasons and three levels of nitrogen fertilizer application and one control: 0, 60, 80 and 120 kg N ha-1. The nitrogen source was urea. The experimental design was complete random blocks with factorial array and four replications. The occurrence of cv. Cobalto sunflower phenological stages were not modified by the treatments. Urea favored agronomic efficiency and water use efficiency. Yield components were modified positively, with increasing receptacle area, 100-grain weight, and grain yield per receptacle. Application of nitrogen fertilizer favored sunflower development, although environmental conditions are of critical importance as demonstrated by a clear interaction between the yield response to fertilizer application and the environment where the plants grew.

Seed priming is a practice for improving the expression of seed physiological potential. Such technique consists of synchronizing and reducing the time of seed germination by controlled hydration. The aim of this study was to evaluate the effect of seed-priming with different sugar sources and concentrations on the physiological quality Urochloa brizantha seeds and initial seedling performance. Before treating, seeds were scarified chemically with concentrated sulphuric acid (H2SO4) for 5 minutes to overcome physical dormancy. The experimental design was completely randomized in a 3 x 6 factorial scheme consisting of priming using three sugar sources (glucose, sucrose, and maltose) and six concentrations (zero water control, 2%, 5%, 10%, 15%, and 20%), with four replicates. The seeds were primed by direct immersion for 2 hours at 25 ºC and, after hydration, they were dried for moisture equilibrium recovery. Seed germination, vigor, viability, and initial seedling growth were evaluated. The results showed that glucose was the source able to promote beneficial effects on the germination of U. brizantha cv. MG-5 seeds. Moreover, the supply of glucose at the concentrations of 2 and 5% for physiological conditioning increased seedling dry phytomass.

ABSTRACT Seed priming is a practice for improving the expression of seed physiological potential. Such technique consists of synchronizing and reducing the time of seed germination by controlled hydration. The aim of this study was to evaluate the effect of seed-priming with different sugar sources and concentrations on the physiological quality Urochloa brizantha seeds and initial seedling performance. Before treating, seeds were scarified chemically with concentrated sulphuric acid (H2SO4) for 5 minutes to overcome physical dormancy. The experimental design was completely randomized in a 3 x 6 factorial scheme consisting of priming using three sugar sources (glucose, sucrose, and maltose) and six concentrations (zero [water control], 2%, 5%, 10%, 15%, and 20%), with four replicates. The seeds were primed by direct immersion for 2 hours at 25 ºC and, after hydration, they were dried for moisture equilibrium recovery. Seed germination, vigor, viability, and initial seedling growth were evaluated. The results showed that glucose was the source able to promote beneficial effects on the germination of U. brizantha cv. MG-5 seeds. Moreover, the supply of glucose at the concentrations of 2 and 5% for physiological conditioning increased seedling dry phytomass. | RESUMO O condicionamento em sementes é uma prática capaz de possibilitar maior expressão do potencial fisiológico das sementes. Esta técnica permite a sincronização e redução do tempo de germinação das sementes através da hidratação controlada. O objetivo foi avaliar o efeito do condicionamento fisiológico em sementes de Urochloa brizantha com diferentes fontes e concentrações de glicídios na qualidade fisiológica de sementes e desempenho inicial das plântulas. Anterior a aplicação do priming as sementes foram submetidas a escarificação química com ácido sulfúrico concentrado (H2SO4) por 5 minutos para remoção da dormência primária. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 3 x 6, constituído por condicionamento fisiológico utilizando três fontes de glicídios (glicose, sacarose e maltose) e seis concentrações (zero [controle em água], 2%, 5%, 10%, 15% e 20%), com quatro repetições. O condicionamento fisiológico utilizado foi via imersão direta por 2 horas a 25 ºC e, posteriormente a hidratação das sementes, foi realizada a secagem para a retomada da umidade de equilíbrio. Foi realizado teste de germinação, vigor, viabilidade das sementes e crescimento inicial de plântulas. A glicose como fonte de glicídio promoveu efeitos benéficos na germinação de sementes de U. brizantha cv. MG-5. O fornecimento de glicose nas concentrações de 2 e 5% pelo condicionamento fisiológico propiciaram incremento na fitomassa seca de plântulas.

No-tillage cotton systems require soil coverage with cover crop residue for a longer time due to the late cycle of cotton. However, decomposition rates may vary between cover crops, and the adjustment of models to describe it is critical to no-tillage cotton management. Two non-linear regression models, exponential (EM) and Michaelis-Menten (MM), were adjusted to dry matter decomposition of cover crops in a cotton no-tillage system, in Brazil. Three field trials were performed in 2012 for the cover crops Urochloa ruziziensis (brachiaria), Pennisetum glaucum (pearl millet), and Cajanus cajan (pigeon pea). Samples of cover crop were collected at 20, 50, 70, 110, 140, and 170 days after sowing upland cotton to measure dry matter decomposition. MM showed better adjustment than EM for all cover crops. The estimations of half-life parameters were different between the cover crops, suggesting that each cover crop has its own rate of decomposition. For pearl millet, brachiaria, and pigeon pea, the half-life estimation by exponential model was over the MM in 9, 12, and 12 days.

ABSTRACT No-tillage cotton systems require soil coverage with cover crop residue for a longer time due to the late cycle of cotton. However, decomposition rates may vary between cover crops, and the adjustment of models to describe it is critical to no-tillage cotton management. Two non-linear regression models, exponential (EM) and Michaelis-Menten (MM), were adjusted to dry matter decomposition of cover crops in a cotton no-tillage system, in Brazil. Three field trials were performed in 2012 for the cover crops Urochloa ruziziensis (brachiaria), Pennisetum glaucum (pearl millet), and Cajanus cajan (pigeon pea). Samples of cover crop were collected at 20, 50, 70, 110, 140, and 170 days after sowing upland cotton to measure dry matter decomposition. MM showed better adjustment than EM for all cover crops. The estimations of half-life parameters were different between the cover crops, suggesting that each cover crop has its own rate of decomposition. For pearl millet, brachiaria, and pigeon pea, the half-life estimation by exponential model was over the MM in 9, 12, and 12 days. | RESUMO Para a semeadura direta é preciso adequada quantidade de palha sobre o solo, e devido ao longo ciclo do algodoeiro, sua persistência deve ser alta. Entretanto, como a decomposição dos resíduos vegetais ao longo do tempo pode variar entre as plantas de cobertura, o ajuste de modelos que melhor a descreva é essencial. Dois modelos de regressão não-linear, exponencial (ME) e Michaelis-Menten (MM), foram ajustados à decomposição de matéria seca de plantas de cobertura no sistema de semeadura direta do algodoeiro, em condições do Cerrado goiano. Três experimentos foram instalados no ano de 2012, cada um consistido de uma espécie de planta de cobertura, sendo Urochloa ruziziensis (braquiária ruziziensis), Pennisetum glaucum (milheto) e Cajanus cajan (guandu). Em cada ensaio, procedeu-se a amostragem da palha da planta de cobertura aos 20, 50, 70, 110, 140 e 170 dias após a semeadura do algodoeiro, para determinação da matéria seca remanescente. Para as três plantas de cobertura o modelo MM apresentou melhor ajuste que o ME. As estimativas dos tempos de meia-vida das palhadas via MM diferiram entre as plantas de cobertura, indicando que cada uma possui velocidade de decomposição específica. Para o milheto, o guandu e a braquiária, as estimativas de tempo de meia-vida pelo ME foram superiores às do MM em 9, 12 e 12 dias, respectivamente.

The development of common bean cultivars with early cycle, upright plant architecture, and high grain yield represents marketing advantages to bean farmers. This study aimed to evaluate whether common bean inbred lines differ for phenological, plant architecture, and grain yield traits; analyze the correlations between these traits; and select early and upright common bean lines with high grain yield. To this end, 14 common bean inbred lines were evaluated in two growing seasons in Santa Maria - RS, Brazil. Common bean inbred lines showed significant differences for all traits, except for insertion of the first pod and length of the fourth and fifth internodes. The four superior common bean lines selected by the multiplicative index were CNFP 10794, CNFC 10762, DF 06-09, and BRS Valente. CNFP 10794 presents earliness (flowering and cycle), upright plant architecture (lower values of general adaptation score, lodging, and stay-green phenotype) and high grain yield (higher values of number of pods per plant, number of grains per plant, mass of 100 grains, and grain yield). Mass of 100 grains showed a positive correlation with grain yield (r= 0.68). The indirect selection using mass of 100 grains is of intermediate efficiency to increase grain yield in common bean. CNFP 10794 presents earliness, upright plant architecture, and high grain yield and will be selected for the breeding program.

RESUMO O desenvolvimento de cultivares de feijão de ciclo precoce, de arquitetura ereta e de alta produtividade de grãos representa vantagens mercadológicas para os produtores. Os objetivos deste trabalho foram avaliar se as linhagens de feijão diferem quanto aos caracteres fenológicos, da arquitetura de planta e da produção, estudar as correlações entre esses caracteres e selecionar linhagens precoces, de arquitetura ereta e com alta produtividade de grãos. Para tanto, 14 linhagens de feijão foram avaliadas em duas épocas de cultivo em Santa Maria - RS, Brasil. Diferenças significativas entre as linhagens de feijão foram observadas para todos os caracteres avaliados, exceto para a altura de inserção da primeira vagem, o comprimento do quarto e do quinto entrenó. As quatro melhores linhagens selecionadas pelo índice multiplicativo foram CNFP 10794, CNFC 10762, DF 06-09 e BRS Valente. A linhagem CNFP 10794 apresenta precocidade (floração e ciclo), arquitetura de planta ereta (menores escores de nota geral de adaptação, acamamento e fenótipo stay green) e alta produtividade de grãos (maiores valores de número de vagens por planta, número de grãos por planta, massa de 100 grãos e produtividade de grãos). A massa de 100 grãos apresentou correlação positiva com a produtividade de grãos (r= 0,68). A seleção indireta pela maior massa de 100 grãos é de moderada eficiência para aumentar a produtividade de grãos em feijão. A linhagem CNFP 10794 apresenta precocidade, arquitetura de planta ereta e maior produtividade de grãos e será selecionada pelo programa de melhoramento. | ABSTRACT The development of common bean cultivars with early cycle, upright plant architecture, and high grain yield represents marketing advantages to bean farmers. This study aimed to evaluate whether common bean inbred lines differ for phenological, plant architecture, and grain yield traits; analyze the correlations between these traits; and select early and upright common bean lines with high grain yield. To this end, 14 common bean inbred lines were evaluated in two growing seasons in Santa Maria - RS, Brazil. Common bean inbred lines showed significant differences for all traits, except for insertion of the first pod and length of the fourth and fifth internodes. The four superior common bean lines selected by the multiplicative index were CNFP 10794, CNFC 10762, DF 06-09, and BRS Valente. CNFP 10794 presents earliness (flowering and cycle), upright plant architecture (lower values of general adaptation score, lodging, and stay-green phenotype) and high grain yield (higher values of number of pods per plant, number of grains per plant, mass of 100 grains, and grain yield). Mass of 100 grains showed a positive correlation with grain yield (r= 0.68). The indirect selection using mass of 100 grains is of intermediate efficiency to increase grain yield in common bean. CNFP 10794 presents earliness, upright plant architecture, and high grain yield and will be selected for the breeding program.

Sesame is a plant with high morphological and physiological complexity, with great variability in growth habit. Quantitative growth analysis is an accessible and accurate tool for evaluating plant development and the contribution of different physiological processes to plant performance. In view of this, the purpose of this study was to evaluate the growth of sesame cultivars in two cropping seasons in the conditions of Mossoró-RN. Two experiments were conducted in Horta Didactics of UFERSA. The experimental delineation in each time was a randomized complete block design with four replications. The treatments were arranged in split plots where each experimental plot contained different sesame cultivars, CNPA G2, CNPA G3 and CNPA G4, and the subplots represented seven collection times, 21, 35, 49, 63, 77, 91 and 105 days after sowing (DAS). The growth of the sesame cultivars was slow at the beginning of the crop cycle, intensifying at the beginning of flowering (after 35 DAS). Among the physiological indexes studied, CNPA G4 cultivar was more efficient in relation to growth and varied depending on the cropping season.

RESUMO O gergelim é uma cultura de elevada complexidade morfofisiológica, com grande variabilidade no hábito de crescimento. A análise quantitativa do crescimento é uma ferramenta acessível e precisa para avaliar o desenvolvimento vegetal e a contribuição de diferentes processos fisiológicos sobre o seu desempenho. Nesse sentido, objetivou-se avaliar o crescimento de cultivares de gergelim em duas épocas de cultivo nas condições de Mossoró-RN. Foram instalados dois experimentos na Horta Didática da UFERSA. O delineamento experimental em cada época foi em blocos casualizados completos, com quatro repetições. Os tratamentos foram dispostos em parcelas subdivididas, onde as parcelas foram representadas pelas cultivares de gergelim: CNPA G2, CNPA G3 e CNPA G4 e as subparcelas consistiram das épocas de coletas (21; 35; 49; 63; 77; 91 e 105 DAS). O crescimento das cultivares de gergelim é lento no início do ciclo vegetativo da cultura, se intensificando no início do florescimento (após os 35 DAS). Entre os índices fisiológicos estudados, a cultivar CNPA G4 apresenta ser mais eficiente em relação ao crescimento, podendo ser variado dependendo da época de cultivo. | ABSTRACT Sesame is a plant with high morphological and physiological complexity, with great variability in growth habit. Quantitative growth analysis is an accessible and accurate tool for evaluating plant development and the contribution of different physiological processes to plant performance. In view of this, the purpose of this study was to evaluate the growth of sesame cultivars in two cropping seasons in the conditions of Mossoró-RN. Two experiments were conducted in Horta Didactics of UFERSA. The experimental delineation in each time was a randomized complete block design with four replications. The treatments were arranged in split plots where each experimental plot contained different sesame cultivars, CNPA G2, CNPA G3 and CNPA G4, and the subplots represented seven collection times, 21, 35, 49, 63, 77, 91 and 105 days after sowing (DAS). The growth of the sesame cultivars was slow at the beginning of the crop cycle, intensifying at the beginning of flowering (after 35 DAS). Among the physiological indexes studied, CNPA G4 cultivar was more efficient in relation to growth and varied depending on the cropping season.

The low use of technologies by farmers and the occurrence of biotic and abiotic stresses are limiting factors for cowpea production in the Brazilian Northeast region. The tolerance of genotypes to drought is an alternative to decrease the negative effects of stresses on cowpea production. Thus, the objective of this work was to identify parents and combinations of cowpea genotypes with high probability of generating segregating populations with tolerance to drought. Six cowpea genotypes were crossed in a complete diallel cross design, totaling 30 F2 populations, which were evaluated together with their parents in an experiment under water deficit at the experimental field of the Embrapa Mid-North, Teresina, State of Piauí, Brazil. A triple lattice incomplete block experiment design was used, with three replications, with experimental plot consisting of six 2-m plant rows. Fifteen plants per plot were sampled to evaluate their agronomic characteristics, whose results were subjected to analysis of variance and means were used to estimate the general and specific combining abilities. The genotypes showed significant differences in all characteristics evaluated, denoting the genetic variability of the population. The additive effects were more important than the non-additive effects, and maternal inheritance was detected. The genotypes BRS Xiquexique, Pingo-de-Ouro-1-2 and MNC99-510F-16-1 were the most promising for use in recurrent selection programs for tolerance to water deficit. The hybrid combinations (1) BRS Paraguaçu X (4) CNCx-698-128G, (2) Pingo-de-Ouro-1-2 X (3) BRS Xiquexique, (3) BRS Xiquexique X (5) Santo-Inácio, (4) CNCx-698-128G X (6) MNC99-510F-16-1 and (5) Santo-Inácio X (4) CNCx-698-128G showed potential for generating superior lineages regarding bean production and tolerance to water deficit.

ABSTRACT The low use of technologies by farmers and the occurrence of biotic and abiotic stresses are limiting factors for cowpea production in the Brazilian Northeast region. The tolerance of genotypes to drought is an alternative to decrease the negative effects of stresses on cowpea production. Thus, the objective of this work was to identify parents and combinations of cowpea genotypes with high probability of generating segregating populations with tolerance to drought. Six cowpea genotypes were crossed in a complete diallel cross design, totaling 30 F2 populations, which were evaluated together with their parents in an experiment under water deficit at the experimental field of the Embrapa Mid-North, Teresina, State of Piauí, Brazil. A triple lattice incomplete block experiment design was used, with three replications, with experimental plot consisting of six 2-m plant rows. Fifteen plants per plot were sampled to evaluate their agronomic characteristics, whose results were subjected to analysis of variance and means were used to estimate the general and specific combining abilities. The genotypes showed significant differences in all characteristics evaluated, denoting the genetic variability of the population. The additive effects were more important than the non-additive effects, and maternal inheritance was detected. The genotypes BRS Xiquexique, Pingo-de-Ouro-1-2 and MNC99-510F-16-1 were the most promising for use in recurrent selection programs for tolerance to water deficit. The hybrid combinations (1) BRS Paraguaçu X (4) CNCx-698-128G, (2) Pingo-de-Ouro-1-2 X (3) BRS Xiquexique, (3) BRS Xiquexique X (5) Santo-Inácio, (4) CNCx-698-128G X (6) MNC99-510F-16-1 and (5) Santo-Inácio X (4) CNCx-698-128G showed potential for generating superior lineages regarding bean production and tolerance to water deficit. | RESUMO A baixa adoção de tecnologias pelos agricultores e a ocorrência de estresses bióticos e abióticos são fatores que limitam a produção do feijão-caupi na região Nordeste do Brasil. A tolerância de genótipos à seca é uma das formas para diminuir os efeitos negativos dos estresses sobre a produtividade. O objetivo deste trabalho foi identificar genitores e combinações promissoras com maior probabilidade de gerarem populações segregantes de feijão-caupi tolerantes à seca. Foi realizado um dialelo completo envolvendo seis genótipos de feijão-caupi, totalizando 30 populações F2, que foram avaliadas, juntamente com seus genitores, em um ensaio sob déficit hídrico, no campo experimental da Embrapa Meio-Norte, em Teresina-PI. Utilizou-se o delineamento experimental látice triplo, com parcela de 6 linhas de 2 m, sendo amostradas 15 plantas por parcela. Foram avaliados caracteres agronômicos e submetidos à análise de variância e, utilizando-se das médias, obtiveram-se as estimativas de capacidade geral e específica de combinação. Observou-se diferenças significativas para todos os caracteres, evidenciando a existência de variabilidade genética na população. Os efeitos aditivos foram mais importantes que os efeitos não aditivos, sendo também constatada a presença de herança materna. Os genótipos BRS Xiquexique, Pingo de Ouro-1-2 e MNC99- 510F-16-1 foram os mais promissores para utilização em programa de seleção recorrente visando tolerância ao déficit hídrico. As combinações híbridas (1) BRS Paraguaçu X (4) CNCx 698-128G, (2) Pingo de Ouro-1-2 X (3) BRS Xiquexique, (3) BRS Xiquexique X (5) Santo Inácio, (4) CNCx 698-128G X (6) MNC99-510F-16-1 e (5) Santo Inácio X (4) CNCx 698-128G, possuem potencial simultâneos para extração de linhagens superiores quanto à produtividade de grãos e tolerantes ao déficit hídrico.

Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha-1) and four levels of N (0, 67, 134, and 268 kg ha-1) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha-1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K.

ABSTRACT Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha-1) and four levels of N (0, 67, 134, and 268 kg ha-1) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha-1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K. | RESUMO A adubação é importante para otimizar o crescimento e produtividade, sendo necessario para atividade agrícola. A adubação de solo deve aumentar o lucro líquido, que depende da eficiência de uso de nutrientes pela planta. O objetivo deste estudo foi avaliar a eficiência agronômica em berinjela sob diferentes doses de potássio (K) e nitrogênio (N). Quatro níveis de K (0, 54, 108 e 216 kg de K ha-1) e quatro níveis de N (0, 67, 134 e 268 kg de N ha-1) foram aplicados semanalmente via fertirrigação. As plantas mais altas e com maior diâmetro de caule foram obtidas com 165-175 kg ha-1 de N. A área foliar foi mais influenciada pelo nitrogênio em comparação com o potássio. Aplicações isoladas de diferentes doses de K não influenciaram a altura de planta, diâmetro de caule e matéria seca da folha. A eficiência agronômica do nitrogênio é reduzida com o aumento da dose de N e K.

Here we aimed to evaluate the influence of cladode morphology on the canopy formation of forage cactus plants. The study was carried out in Serra Talhada, the State of Pernambuco, using the IPA Sertânia (IPA), Miúda (MIU), and Orelha de Elefante Mexicana (OEM) clones, which were submitted to three irrigation depths (2.5, 5.0, or 7.5 mm) and three irrigation intervals (7, 14, or 28 days) from March 2012 to August 2013. Cladode and plant canopy biometric data were obtained during the experimental period. We found that the characteristics of the second and third order cladodes contributed most to the canopy formation of clones of the genus Nopalea (IPA and MIU), whereas, for the genus Opuntia (OEM), the first and third order cladodes contributed most. Overall, we found that the influence of the cladode variables on the canopy growth of forage cactus is more associated with the characteristics of the genus than to the peculiarities of the clones.

RESUMO O objetivo foi avaliar a influência das características morfológicas dos cladódios sobre a formação do dossel da palma forrageira. O estudo foi conduzido em Serra Talhada, PE, com os clones IPA Sertânia - IPA, Miúda - MIU e Orelha de Elefante Mexicana - OEM, os quais foram submetidos a três lâminas (2,5; 5,0; e 7,5 mm) e três intervalos de irrigação (7; 14 e 28 dias), no período compreendido entre março 2012 a agosto de 2013. Dados das dimensões dos cladódios e do dossel das plantas foram obtidos ao longo do tempo. A matriz de correlação de Pearson foi elaborada, e análises canônicas e de trilha foram aplicadas para avaliação da associação entre as variáveis. Verificou-se que, as características dos cladódios de 2ª e de 3ª ordens foram as que mais contribuíram na formação do dossel dos clones do gênero Nopalea (IPA Sertânia e Miúda), enquanto para a Orelha de Elefante Mexicana do gênero Opuntia foram as dos cladódios de primeira 1ª e 3ª ordens. Conclui-se que, a influência das variáveis dos cladódios sobre o crescimento do dossel da palma forrageira esteve mais associada às características do gênero, do que a peculiaridades dos clones. | ABSTRACT Here we aimed to evaluate the influence of cladode morphology on the canopy formation of forage cactus plants. The study was carried out in Serra Talhada, the State of Pernambuco, using the IPA Sertânia (IPA), Miúda (MIU), and Orelha de Elefante Mexicana (OEM) clones, which were submitted to three irrigation depths (2.5, 5.0, or 7.5 mm) and three irrigation intervals (7, 14, or 28 days) from March 2012 to August 2013. Cladode and plant canopy biometric data were obtained during the experimental period. We found that the characteristics of the second and third order cladodes contributed most to the canopy formation of clones of the genus Nopalea (IPA and MIU), whereas, for the genus Opuntia (OEM), the first and third order cladodes contributed most. Overall, we found that the influence of the cladode variables on the canopy growth of forage cactus is more associated with the characteristics of the genus than to the peculiarities of the clones.

The GGE Biplot method is efficien to identify favorable genotypes and ideal environments for evaluation. Therefore, the objective of this work was to evaluate the genotype by environment interaction (G×E) and select elite lines of cowpea from genotypes, which are part of the cultivation and use value tests of the Embrapa Meio-Norte Breeding Program, for regions of the Brazilian Cerrado, by the GGE-Biplot method. The grain yield of 40 cowpea genotypes, 30 lines and 10 cultivars, was evaluated during three years (2010, 2011 and 2012) in three locations: Balsas (BAL), São Raimundo das Mangabeiras (SRM) and Primavera do Leste (PRL). The data were subjected to analysis of variance, and adjusted means were obtained to perform the GGE-Biplot analysis. The graphic results showed variation in the performance of the genotypes in the locations evaluated over the years. The performance of the lines MNC02-675F-4-9 and MNC02-675F-4-10 were considered ideal, with maximum yield and good stability in the locations evaluated. There mega-environments were formed, encompassing environments correlated positively. The lines MNC02-675F-4-9, MNC02-675F-9-3 and MNC02-701F-2 had the best performance within each mega-environment. The environment PRL10 and lines near this environment, such as MNC02-677F-2, MNC02-677F-5 and the control cultivar (BRS-Marataoã) could be classified as those of greater reliability, determined basically by the genotypic effects, with reduced G×E. Most of the environments evaluated were ideal for evaluation of G×E, since the genotypes were well discriminated on them. Therefore, the selection of genotypes with adaptability and superior performance for specific environments through the GGE-Biplot analysis was possible.

RESUMO O método GGE Biplot é eficiente em identificar genótipos favoráveis e ambientes ideais para avaliação. Portanto, o objetivo deste trabalho foi avaliar a interação genótipo por ambientes (G×A) de linhagens elite de feijão-caupi nos ensaios de valor de cultivo e uso (VCU) da Embrapa Meio-Norte, realizados nas regiões de Cerrado do Brasil, por meio de analises via GGE Biplot. Avaliou-se a produtividade de grãos em 40 genótipos de feijão-caupi, sendo 30 linhagens e 10 cultivares, durante três anos (2010, 2011 e 2012) em três locais: Balsas (BAL), São Raimundo das Mangabeiras (SRM) e Primavera do Leste (PRL). Os dados foram submetidos a análises de variância, a partir da qual foram obtidas as médias ajustadas para realizar a análise via GGE-Biplot. Os resultados gráficos revelam que houve variação no comportamento dos genótipos nos locais avaliados ao longo dos anos. As linhagens MNC02-675F-4-9 e MNC02-675F-4-10 apresentaram desempenhos de um genótipo ideal, com máxima produtividade aliada à boa estabilidade nos locais de avaliação. Houve a formação de três mega-ambientes que englobaram ambientes correlacionados positivamente. As linhagens MNC02-675F-4-9, MNC02-675F-9-3 e MNC02-701F-2 apresentaram o melhor desempenho médio dentro de cada mega-ambiente. O ambiente PRL10 e as linhagens próximas a este ambiente, como MNC02-677F-2, MNC02-677F-5 e a cultivar testemunha BRS-Marataoã, puderam ser classificados com maior confiabilidade, determinados basicamente pelos efeitos genotípicos, com G×A reduzida. A maioria dos ambientes avaliados foram ideais para avaliação da G×A, discriminando bem os genótipos. Portanto, a análise GGE-Biplot, permitiu selecionar genótipos com adaptabilidade e desempenhos superiores para ambientes específicos. | ABSTRACT The GGE Biplot method is efficien to identify favorable genotypes and ideal environments for evaluation. Therefore, the objective of this work was to evaluate the genotype by environment interaction (G×E) and select elite lines of cowpea from genotypes, which are part of the cultivation and use value tests of the Embrapa Meio-Norte Breeding Program, for regions of the Brazilian Cerrado, by the GGE-Biplot method. The grain yield of 40 cowpea genotypes, 30 lines and 10 cultivars, was evaluated during three years (2010, 2011 and 2012) in three locations: Balsas (BAL), São Raimundo das Mangabeiras (SRM) and Primavera do Leste (PRL). The data were subjected to analysis of variance, and adjusted means were obtained to perform the GGE-Biplot analysis. The graphic results showed variation in the performance of the genotypes in the locations evaluated over the years. The performance of the lines MNC02-675F-4-9 and MNC02-675F-4-10 were considered ideal, with maximum yield and good stability in the locations evaluated. There mega-environments were formed, encompassing environments correlated positively. The lines MNC02-675F-4-9, MNC02-675F-9-3 and MNC02-701F-2 had the best performance within each mega-environment. The environment PRL10 and lines near this environment, such as MNC02-677F-2, MNC02-677F-5 and the control cultivar (BRS-Marataoã) could be classified as those of greater reliability, determined basically by the genotypic effects, with reduced G×E. Most of the environments evaluated were ideal for evaluation of G×E, since the genotypes were well discriminated on them. Therefore, the selection of genotypes with adaptability and superior performance for specific environments through the GGE-Biplot analysis was possible.