Sorghum hybrids grown in hydroponics contrast for phosphorus use efficiency

Abstract Phosphorus (P) use efficiency is crucial for sorghum production. P acquisition efficiency is the most important component of P use efficiency. The early-stage evaluation of plant development is a useful tool for identifying P-efficient genotypes. This study aimed to identify sorghum hybrids that are efficient in P use efficiency and assess the genetic diversity among hybrids based on traits related to P acquisition efficiency. Thus, 38 sorghum hybrids and two inbred lines (checks) were evaluated under low and high P in a paper pouch system with nutrient solution. Biomass and root traits related to P efficiency were measured. There was no interaction between genotypes and P levels concerning all evaluated traits. The biomass and root traits, except root diameter, presented smaller means under low P than high P. Efficient and inefficient hybrids under each P level were identified. The genetic diversity assessment grouped these genotypes in different clusters. The hybrids AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540, and DKB 590 were superior under low-P and high-P. Hybrids SC121, 1236020 e 1167017 presented the lowest means than all other hybrids, under both conditions. The evaluated hybrids showed phenotypic diversity for traits related to P acquisition, such as root length and root surface area, which can be useful for establishing selection strategies for sorghum breeding programs and increasing P use efficiency.

Resumo A eficiência do uso do fósforo (P) é fundamental para a produção de sorgo. A avaliação no estágio inicial do desenvolvimento da planta é uma ferramenta útil para a identificação de genótipos eficientes de P. Este trabalho teve como objetivo identificar híbridos de sorgo que sejam eficientes ao uso de P e avaliar a diversidade genética entre os híbridos com base em características relacionadas à eficiência de aquisição de P. Assim, 38 híbridos de sorgo e duas linhagens (testemunhas) foram avaliados sob baixo e alto P em sistema de pastas de papel com solução nutritiva. Características de biomassa e de raiz relacionadas à eficiência de P foram mensuradas. Não houve interação entre genótipos e níveis de P em todas as características avaliadas. As características de biomassa e raiz, exceto o diâmetro da raiz, apresentaram médias menores sob baixo P em comparação com alto P. Híbridos eficientes e ineficientes sob cada nível de P foram identificados e agrupados quanto à diversidade genética. Os híbridos AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540 e DKB 590 foram superiores sob baixo-P e alto-P. Os híbridos SC121, 1236020 e 1167017 apresentaram as menores médias que todos os outros híbridos, em ambas condições. Os híbridos avaliados apresentaram diversidade fenotípica para características relacionadas à aquisição de P, como comprimento e área superficial da raiz, o que pode ser útil para estabelecer estratégias de seleção para programas de melhoramento de sorgo e aumentar a eficiência de uso do P.

Sorghum hybrids grown in hydroponics contrast for phosphorus use efficiency / Híbridos de sorgo crescidos em hidroponia contrastam para eficiência de uso de fósforo

Phosphorus (P) use efficiency is crucial for sorghum production. P acquisition efficiency is the most important component of P use efficiency. The early-stage evaluation of plant development is a useful tool for identifying P-efficient genotypes. This study aimed to identify sorghum hybrids that are efficient in P use efficiency and assess the genetic diversity among hybrids based on traits related to P acquisition efficiency. Thus, 38 sorghum hybrids and two inbred lines (checks) were evaluated under low and high P in a paper pouch system with nutrient solution. Biomass and root traits related to P efficiency were measured. There was no interaction between genotypes and P levels concerning all evaluated traits. The biomass and root traits, except root diameter, presented smaller means under low P than high P. Efficient and inefficient hybrids under each P level were identified. The genetic diversity assessment grouped these genotypes in different clusters. The hybrids AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540, and DKB 590 were superior under low-P and high-P. Hybrids SC121, 1236020 e 1167017 presented the lowest means than all other hybrids, under both conditions. The evaluated hybrids showed phenotypic diversity for traits related to P acquisition, such as root length and root surface area, which can be useful for establishing selection strategies for sorghum breeding programs and increasing P use efficiency.

A eficiência do uso do fósforo (P) é fundamental para a produção de sorgo. A avaliação no estágio inicial do desenvolvimento da planta é uma ferramenta útil para a identificação de genótipos eficientes de P. Este trabalho teve como objetivo identificar híbridos de sorgo que sejam eficientes ao uso de P e avaliar a diversidade genética entre os híbridos com base em características relacionadas à eficiência de aquisição de P. Assim, 38 híbridos de sorgo e duas linhagens (testemunhas) foram avaliados sob baixo e alto P em sistema de pastas de papel com solução nutritiva. Características de biomassa e de raiz relacionadas à eficiência de P foram mensuradas. Não houve interação entre genótipos e níveis de P em todas as características avaliadas. As características de biomassa e raiz, exceto o diâmetro da raiz, apresentaram médias menores sob baixo P em comparação com alto P. Híbridos eficientes e ineficientes sob cada nível de P foram identificados e agrupados quanto à diversidade genética. Os híbridos AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540 e DKB 590 foram superiores sob baixo-P e alto-P. Os híbridos SC121, 1236020 e 1167017 apresentaram as menores médias que todos os outros híbridos, em ambas condições. Os híbridos avaliados apresentaram diversidade fenotípica para características relacionadas à aquisição de P, como comprimento e área superficial da raiz, o que pode ser útil para estabelecer estratégias de seleção para programas de melhoramento de sorgo e aumentar a eficiência de uso do P.

Identification, expression and DNA variation analysis of high affinity nitrate transporter NRT2/3 gene family in Sorghum bicolor / 生物工程学报

Nitrate is the main form of inorganic nitrogen that crop absorbs, and nitrate transporter 2 (NRT2) is a high affinity transporter using nitrate as a specific substrate. When the available nitrate is limited, the high affinity transport systems are activated and play an important role in the process of nitrate absorption and transport. Most NRT2 cannot transport nitrates alone and require the assistance of a helper protein belonging to nitrate assimilation related family (NAR2) to complete the absorption or transport of nitrates. Crop nitrogen utilization efficiency is affected by environmental conditions, and there are differences between varieties, so it is of great significance to develop varieties with high nitrogen utilization efficiency. Sorghum bicolor has high stress tolerance and is more efficient in soil nitrogen uptake and utilization. The S. bicolor genome database was scanned to systematically analyze the gene structure, chromosomal localization, physicochemical properties, secondary structure and transmembrane domain, signal peptide and subcellular localization, promoter region cis-acting elements, phylogenetic evolution, single nucleotide polymorphism (SNP) recognition and annotation, and selection pressure of the gene family members. Through bioinformatics analysis, 5 NRT2 gene members (designated as SbNRT2-1a, SbNRT2-1b, SbNRT2-2, SbNRT2-3, and SbNRT2-4) and 2 NAR2 gene members (designated as SbNRT3-1 and SbNRT3-2) were identified, the number of which was less than that of foxtail millet. SbNRT2/3 were distributed on 3 chromosomes, and could be divided into four subfamilies. The genetic structure of the same subfamilies was highly similar. The average value of SbNRT2/3 hydrophilicity was positive, indicating that they were all hydrophobic proteins, whereas α-helix and random coil accounted for more than 70% of the total secondary structure. Subcellular localization occurred on plasma membrane, where SbNRT2 proteins did not contain signal peptides, but SbNRT3 proteins contained signal peptides. Further analysis revealed that the number of transmembrane domains of the SbNRT2s family members was greater than 10, while that of the SbNRT3s were 2. There was a close collinearity between NRT2/3s of S. bicolor and Zea mays. Protein domains analysis showed the presence of MFS_1 and NAR2 protein domains, which supported executing high affinity nitrate transport. Phylogenetic tree analysis showed that SbNRT2/3 were more closely related to those of Z. mays and Setaria italic. Analysis of gene promoter cis-acting elements indicated that the promoter region of SbNRT2/3 had several plant hormones and stress response elements, which might respond to growth and environmental cues. Gene expression heat map showed that SbNRT2-3 and SbNRT3-1 were induced by nitrate in the root and stem, respectively, and SbNRT2-4 and SbNRT2-3 were induced by low nitrogen in the root and stem. Non-synonymous SNP variants were found in SbNRT2-4 and SbNRT2-1a. Selection pressure analysis showed that the SbNRT2/3 were subject to purification and selection during evolution. The expression of SbNRT2/3 gene and the effect of aphid infection were consistent with the expression analysis results of genes in different tissues, and SbNRT2-1b and SbNRT3-1 were significantly expressed in the roots of aphid lines 5-27sug, and the expression levels of SbNRT2-3, SbNRT2-4 and SbNRT3-2 were significantly reduced in sorghum aphid infested leaves. Overall, genome-wide identification, expression and DNA variation analysis of NRT2/3 gene family of Sorghum bicolor provided a basis for elucidating the high efficiency of sorghum in nitrogen utilization.

Multiple resistance to primary pests of grain sorghum hybrids: Spodoptera frugiperda (Lepidoptera: Noctuidae), Diatraea saccharalis (Lepidoptera: Crambidae), and Diceraeus melacanthus (Hemiptera: Pentatomidae)

ABSTRACT Plant resistance is an important tactic within the precepts of Integrated Pest Management, and the existence of grain sorghum hybrids with multiple insect resistance could benefit crop management and sustainability. This study evaluated the susceptibility of 30 grain-sorghum hybrids to three major pests, namely, fall armyworm (FAW) Spodoptera frugiperda, sugarcane borer (SCB) Diatraea saccharalis, and green-belly stink bug (GBS) Diceraeus melacanthus. The hybrids were cultivated and experiments with each insect species were conducted separately in a greenhouse. For FAW, visual injury assessments were performed on plants 7 and 14 days after infestation (DAI). For SCB, insect presence and injury were assessed 40 DAI. For GBS, the plants were evaluated using a damage rating scale 12, 19, and 26 DAI. Cluster analysis allowed separating the grain sorghum hybrids into groups regarding the levels of resistance to each pest. Hybrid BRS373 stood out as moderately resistant to FAW; AG1090, 80G20, BRAVO, BRS373, AG1615, and IG220 were the most promising for SCB; and for GBS, hybrids 50A40, A9735R, JADE, ENFORCER, BUSTER, 50A10, and IG244 were the most nominated. This information will significantly aid sorghum breeding programs focused on developing commercial hybrids that comprise both insect-resistance and high-yield characteristics. However, further research should evaluate potential chemical and morphological plant traits underlying the lower levels of susceptibility to FAW, SCB, and GBS found in the selected sorghum hybrids.

Can a successional crop system associated with preemergent herbicides be a tool to control weeds?

The objective of this research was to evaluate weed control in a successional soybean-sorghum system by using preemergent herbicides. Two trials were conducted in soybean and two in sorghum, in different soil types (sandy in Rio Verde city and clayey in Montividiu city). All trials were established in a completely randomized block design with five preemergent herbicides in soybean (rates in): diclosulam 35.3 g a.i.·ha­1, chlorimuron 20 g a.i.·ha­1, sulfentrazone 200 g a.i.·ha­1, flumioxazin 50 g a.i.·ha­1, S-metolachlor 1728 g a.i.·ha­1, and two controls (hand weeded and untreated). Treatments in sorghum trials were the same to the soybean plus atrazine 1250 g a.i.·ha­1 and atrazine 1250 g a.i.·ha­1 + S-metolachlor 1728 g a.i.·ha­1. All treatments had four replicates. Weed control was assessed at 7, 14, 21 and 28 days after planting (DAP) in both crops. In addition, yield was measured when grains reached physiological maturity. All preemergent herbicide treatments successfully controlled weeds, specially Commelina benghalensis, Cenchrus echinatus and Eleusine indica, in both soybean trials until 28 DAP. In some weeds of sorghum, sulfentrazone, diclosulam and chlorimuron sprayed at soybean preemergence performed better than atrazine sprayed at sorghum preemergence. All preemergent herbicides sprayed at soybean preemergence did not affect soybean and sorghum yield, showing similarity with the hand weeded treatment. The results of this research provide evidence that the mix of crop succession and preemergent herbicide applications can be a strong strategy for integrated weed management.

Liming and biochar on sorghum growth and Arenosol chemical properties in the Semiarid environment / Efeito da calagem e do biochar no crescimento do sorgo e nas propriedades químicas do Neossolo Quartzarênico no ambiente Semiárido

This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential.

Este trabalho teve como objetivo avaliar o efeito da calagem (com e sem) e do biocarvão (com e sem) sobre o crescimento e a produção de forragem do sorgo forrageiro cv. BRS Ponta Negra e nas propriedades químicas do Neossolo Quartzarênico no ambiente Semiárido. O delineamento experimental foi em blocos casualizados, com tratamentos em esquema fatorial 2x2, correspondendo a aplicação ou não do calcário (0 e 2,5 t ha-1) e do biocarvão (0 e 12,5 t ha-1). O biochar era produzido a partir de galhos de caju. O experimento foi conduzido em parcelas de 16 m² onde foi cultivada a cultivar de sorgo forrageiro BRS Ponta Negra. Foram avaliadas as características químicas do solo, os atributos de produção e as características estruturais da cultivar de sorgo estudada. Não houve interação entre os fatores. O uso do biochar aumentou o pH e os teores de Ca e P no solo e contribuiu para o aumento da massa da panícula (2,51 t ha-1 de MS). A aplicação de calcário afetou o teor de Ca no solo, assim a dose de 2,5 t ha-1 resultou em maiores valores de diâmetro do colmo (15,25 mm), massa da panícula e massa do colmo (2,63 e 7,50 t ha-1 de MS, respectivamente). Portanto, esses resultados permitem traçar estrategias de uso do calcário e biochar para produção forrageira em ambientes semiáridos com solos arenosos. Pois, esses materias melhoram alguns atributos quimicos do solo e a produção do sorgo forrageiro. Vale ressaltar que as condições edofoclimáticas podem alterar os padrões de resposta observados nesta pesquisa. Portanto, a pesquisa em outras regiões é essencial.

Triticale silage replaces sorghum silage in finishing of Braford heifers / Silagem de triticale substitui silagem de sorgo na terminação de novilhas da raça Braford

The aim of this study was to evaluate the effect of sorghum silage substitution with different proportions of triticale silage on the performance and carcass of Braford heifers. Twenty-four Braford heifers were randomly assigned to four diets where sorghum silage was replaced at 0%, 30%, 60%, and 100% for triticale silage in a feedlot system. During sixty-tree days of the experiment, the feed intake, feed ratio conversion, and average daily gain were measured. The heifers were slaughtered and the effects of the sorghum and triticale silage in carcass characteristics were evaluated. The replacement of sorghum silage with triticale silage did not affect the feed intake and average daily gain (P> 0.05). Feed gain ratio was higher for the heifers that received lower proportions of triticale silage (0% and 30%) in replace sorghum silage (P <0.05). Eye loin area and fat thickness were similar among treatments (P<0.05). Other carcass characteristics, such as slaughter live weight, dressing percentage, conformation and fat classification were similar among experimental treatments (P<0.005). Triticale silage can replace sorghum silage for finishing beef heifers in feedlot system and provides similar carcass characteristics.(AU)

O objetivo deste trabalho foi avaliar o efeito da substituição da silagem de sorgo por diferentes proporções de silagem de triticale no desempenho e na carcaça de novilhas Braford. A silagem de sorgo foi substituída em 0%, 30%, 60% e 100% pela silagem de triticale como fonte de volumoso na alimentação de 24 novilhas da raça Braford, em um sistema de confinamento. O período experimental total foi de 63 dias para a avaliação do consumo dos componentes da ração, a conversão alimentar e o ganho médio diário. Ao final do experimento, os animais foram abatidos e avaliados em relação às características de carcaça. A substituição da silagem de sorgo pela silagem de triticale não apresentou efeito no consumo dos componentes da ração e no ganho médio diário entre as novilhas (P>0,05). A conversão alimentar foi melhor para as novilhas que receberam menores proporções de silagem de triticale (0% e 30%) em substituição à silagem de sorgo (P<0,05). As características das carcaças foram semelhantes entre os animais independentemente da fonte de volumoso. A silagem de triticale apresenta-se como alimento alternativo à silagem de sorgo em regiões de transição climática para a terminação de novilhas de corte, proporcionando o mesmo desempenho animal e as mesmas características de carcaça.(AU)

Effect of grain particle size on energy values and chemical components of diets for Label Rouge broilers / Efeito da granulometria de grãos nos valores energéticos e componentes bromatológicos da dieta para frangos Label Rouge

ABSTRACT: This study aimed to determine the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) values as well as the metabolizability coefficients of dry matter, protein, and ether extract of corn, pearl millet, and sorghum in different particle sizes for slow-growing broilers. Two experiments were carried out involving 280 chicks of the Label Rouge® Naked Neck broiler line, with 140 chicks allotted to each experiment in a completely randomized design. Treatments consisted of a reference diet and a test diet (60% reference diet + 40% feedstuff). The feedstuffs were tested and particle size (expressed as geometric mean diameter [GMD, μm] and geometric standard deviation [GSD], respectively) results were 816 and 1.73 for coarsely ground corn, 794 and 1.75 for finely ground corn, 1.517 and 1.92 for pearl millet grain, 760 and 1.63 for finely ground pearl millet (Experiment 1); and 1,866 and 1.86 for whole grain sorghum, 919 and 1.62 for coarsely ground sorghum, and 878 and 1.72 for finely ground sorghum (Experiment 2). A metabolism trial was conducted by using the total excreta collection method to obtain the AME and AMEn values as well as the metabolizability coefficients of dry matter, protein, and ether extract. The energy metabolization coefficient did not differ (P > 0.05) between the grains in the different tested particle sizes. However, there was an improvement in the metabolizability coefficients of dry matter, nitrogen, and ether extract as the particle size of corn was increased. In conclusion, larger grain particle sizes improve the metabolizability of nutrients and energy for slow-growing broilers. Whole-grain sorghum has limited nutritional utilization for slow-growing birds up to 21 days of age.

RESUMO: Objetivou-se determinar os valores de energia metabolizável aparente (EMA), corrigida para o balanço de nitrogênio (EMAn), e os coeficientes de metabolizabilidade da matéria seca, proteína e extrato etéreo do milho, milheto e sorgo em diferentes granulometrias para frangos de crescimento lento. Foram desenvolvidos dois experimentos, com 140 pintos de corte da linhagem Label Rouge® Pescoço Pelado, distribuídos em delineamento experimental inteiramente casualizado. Os tratamentos consistiram em rações-teste (ração referência 60% + ingrediente 40%) e uma ração referência. Foram testados os ingredientes e a granulometria expressa como Diâmetro Geométrico médio (DGM, μm) e Desvio Padrão Geométrico (DPG): 816 e 1,73 para milho grosseiramente moído, 794 e 1,75 para milho finamente moído, 1,517 e 1,92 para milheto-grão e 760 e 1,73 para milheto finamente moído (Experimento 1); 1.866 e 1.86 para sorgo-grão, 919 e 1,62 para sorgo grosseiramente moído e 878 e 1,72 para sorgo finamente moído (Experimento 2). Os valores de AME e AMEn e os coeficientes de metabolização da matéria seca, proteína e extrato etéreo foram determinados pelo método de coleta total de excretas. O coeficiente de metabolização da energia não apresentou diferença (P > 0,05) entre os grãos nas diferentes granulometrias. Os coeficientes de metabolização da matéria seca, do nitrogênio e do extrato etéreo foram incrementados com o aumento da granulometria para o milho. O fornecimento de grãos com maiores granulometrias proporciona aos frangos de crescimento lento a melhora na metabolizabilidade dos nutrientes e energia. Grãos inteiros de sorgo tem aproveitamento nutricional limitado para frangos de crescimento lento até 21 dias de idade.

Substituição do milho pelo sorgo sobre o desempenho zootécnico e na digestibilidade em coelhos / Replacement of corn by sorghum on zootechnical performance and digestibility in rabbits

O milho é a principal fonte de energia nas dietas animais. Em algumas regiões brasileiras, sua disponibilidade, principalmente na entressafra, é insuficiente para atender à demanda, fazendo com que seu preço se eleve. Neste estudo, objetivou-se avaliar a substituição do milho pelo sorgo sobre o desempenho zootécnico e a digestibilidade em coelhos. Foram utilizados 60 animais machos da raça Nova Zelândia Branco, divididos em três tratamentos: ração base milho (TM); ração base sorgo (TS) e ração base 50% de milho + 50% de sorgo (TMS). No ensaio de desempenho, avaliou-se ganho de peso (GP), consumo de ração (CR), conversão alimentar (CA), coeficientes de digestibilidade da matéria seca (CDMS), proteína bruta (CDPB), fibra em detergente neutro (CDFDN) e fibra em detergente ácido (CDFDA). Observou-se que o CRM, a CA e o GPM não foram afetados pela substituição do milho pelo sorgo, nos níveis de 50% e 100%. Os resultados de digestibilidade demonstraram maiores CDPB e CDFDN na ração base milho, não havendo diferenças entre os demais parâmetros estudados. O sorgo com baixo teor de tanino pode ser usado nas rações de crescimento de coelhos em níveis de substituição de 50% ou 100% da participação do milho, sem prejuízos para o desempenho zootécnico e a digestibilidade.(AU)

Corn is the main source of energy in animal diets. In some Brazilian regions, its availability, especially in the off-season, may be insufficient to meet demand, which causes prices to increase. In this context, the aim of this study was to evaluate the substitution of maize by sorghum on the performance and digestibility of rabbits. Sixty New Zealand White bucks were used, divided in three treatments, maize base ration (TM); based on grain sorghum ration (TS) and base ration 50% corn + 50% sorghum grain (TMS). In the performance test, weight gain (GP), feed intake (CR) and feed conversion ratio (CA) were evaluated. In the digestibility assay, 21 animals were used. The total dry matter (CDMS), crude protein (CDPB), gross energy (EB), neutral detergent fiber (CDFDN) and acid detergent fiber (CDFDA) coefficients were evaluated. There was no significant difference for any of the performance parameters studied (P > 0.05). The digestibility results showed higher CDPB and CDFDN in the corn diet (P <0.05), with no differences between the other parameters studied. Low tannin sorghum can be used in rabbit growth diets at substitution levels of 50% or 100% of maize participation without impairing zootechnical performance and digestibility.(AU)

Greek yogurt with added sorghum flours: antioxidant potential and sensory acceptance / Yogurt griego adicionado de harinas integrales de sorgo: potencial antioxidante y evaluación sensorial

ABSTRACT The aim of this study was to develop and evaluate the antioxidant characteristics and sensory acceptance of Greek yogurt with added whole sorghum flours (WSF) from genotypes BRS305 (tannin) and BR501 (tannin-free). Five formulations were elaborated: 1) Control (without WSF); 2) 2% BR501; 3) 4% BR501; 4) 2% BRS305 and 5) 4% BRS305 and evaluated for antioxidant capacity, total anthocyanins, total phenols, condensed tannins, sensory acceptance and purchase intention. The 4% BRS305 formulation presented higher antioxidant properties, but lower sensory acceptance. No significant difference was observed for: color, flavor and overall acceptability between the control and 2% BR501; nor for texture and overall acceptability between the control and 4% BR501. Principal component analysis explained that all variables associated with antioxidant properties were positively correlated with the first major component (PC1: 82.7%). The 2% and 4% BR501 formulations were more highly correlated with PC1 (92.7%), as well as the control in relation to sensorial characteristics. The addition of WSF BRS305 improved the antioxidant properties of yogurts and the addition of WSF BR501 did not interfere with the sensory acceptance of the formulations. The similarity of the sensory acceptance of the yogurt containing WSF from the BR 501 genotype to the control, opens perspectives for the insertion of sorghum in human food, using dairy products as suitable matrices, adding potential functionality to this type of product.

RESUMEN El trabajo tuvo como propósito desarrollar y evaluar las características antioxidantes y la aceptación sensorial de yogurt griego con adición de harinas integrales de sorgo (HIS) de los genotipos BRS305 (con taninos) y BR501 (sin taninos). Cinco formulaciones fueron elaboradas: 1) Control (sin HIS); 2) 2% BR501; 3) 4% BR501; 4) 2% BRS305 y 5) 4% BRS305. Las formulaciones fueron evaluadas en función de su actividad antioxidante, antocianinas totales, fenólicos totales, taninos condensados, aceptación sensorial e intención de compra. La formulación 4% BRS305 presentó más propiedades antioxidantes, pero menor aceptación sensorial que las otras formulaciones. No se observó diferencia significativa entre el control y el 2% BR501 para el color, sabor e impresión global, ni tampoco para textura e impresión global en relación al 4% BR501. El análisis de componente principal ha explicado que todas las variables asociadas a las propiedades antioxidantes han sido positivamente correlacionadas con el primer componente principal (PC1: 82,7%). Las formulaciones 2% y 4% BR501 se han correlacionado más con el PC1 (92,7%), así como el control con las características sensoriales. La adición de HIS BRS305 ha mejorado las propiedades antioxidantes de los yogurts y la adición de HIS BR501 no ha interferido en la aceptación sensorial de las formulaciones. La similitud de la aceptación sensorial del yogurt que contiene el HIS del genotipo BR501 con el control, abre perspectivas para la inserción del sorgo en la alimentación humana, utilizando productos lácteos como matrices adecuadas, agregando funcionalidad potencial a este tipo de producto.

Estimation of sulfentrazone sorption in isolated application and mixed with glyphosate / Estimativa da sorção do sulfentrazone na aplicação isolada e em mistura com glifosato

The use of herbicides belonging to a single mechanism of action for several consecutive years in the same area may lead to the selection of weed biotypes resistant to herbicides. Weeds resistant to glyphosate have been problem worldwide. As an alternative control, farmers have used glyphosate mixed with sulfentrazone. When two herbicides are mixed, the parameters that govern the behaviour of herbicides in the soil can be altered. In this study, the sorption of sulfentrazone was estimated when applied in isolation with glyphosate formulations. For this, increasing doses of sulfentrazone were applied using Red-Yellow Latosol substrate and washed sand. Each dose of sulfentrazone was applied in a mixture with 1080 g a. e. ha-1 Roundup Ready®, Roundup Ultra® and Zapp Qi®. To evaluate the presence of sulfentrazone in the soil solution, Sorghum bicolor was used as an indicator species. Symptoms of intoxication were evaluated at 7, 14 and 21 days after sowing. At 21 days after sowing, the plants were collected and dried in an oven at 70 ± 10 °C to determine the dry matter. Based on the intoxication of the indicator plants, it was verified that, regardless of the formulation, the presence of glyphosate in the mixture increased the sorption of sulfentrazone in the Red-Yellow Latosol. However, based on dry matter accumulation, sulfentrazone sorption increased because of the mixture with Roundup Ultra®, but decreased due to the presence of Roundup Ready® and Zapp Qi®. Therefore, the application of sulfentrazone in mixture with glyphosate alters the sorptive forces of sulfentrazone in a Red-Yellow Latosol.

A utilização de herbicidas pertencentes a um único mecanismo de ação por vários anos consecutivos na mesma área pode levar a seleção de biótipos de plantas daninhas resistentes a herbicidas. Plantas daninhas resistentes ao glyphosate têm sido problema no mundo inteiro. Como alternativa de controle, os agricultores têm utilizado glyphosate em mistura com sulfentrazone. Quando se misturam duas moléculas herbicidas, os parâmetros que governam o comportamento de herbicidas no solo podem ser alterados. Neste estudo foi estimada a sorção do sulfentrazone quando aplicado de forma isolada e em mistura com formulações de glyphosate. Para isso, doses crescentes de sulfentrazone foram aplicadas utilizando-se como substrato Latossolo Vermelho-Amarelo e areia lavada. Cada uma das doses de sulfentrazone foi aplicada em mistura com 1080 g ha-1 de glyphosate comercializado nas formulações Roundup Ready®, Roundup Ultra® e Zapp Qi®. Para avaliar a presença do sulfentrazone na solução do solo utilizou-se o Sorghum bicolor como espécie indicadora. Os sintomas de intoxicação foram avaliados aos 7, 14 e 21 dias após a semeadura. Aos 21 dias após a semeadura, as plantas foram coletadas e secadas em estufa a 70 ±10C para determinação da matéria seca. Com base na intoxicação das plantas indicadoras, verificou-se que, independente da formulação, a presença glyphosate na mistura, aumentou a sorção do sulfentrazone no Latossolo Vermelho-Amarelo. No entanto com base no acúmulo de matéria seca, constatou-se que a sorção do sulfentrazone aumentou em função da mistura com Roundup Ultra®, mas diminuiu devido a presença de Roundup Ready® e Zapp Qi®. Conclui-se que a aplicação de sulfentrazone em mistura com glyphosate altera as forças sortivas do sulfentrazone no Latossolo Vermelho-Amarelo.

Seed systems of Brachiaria species in intercropping with grain sorghum in the off-season / Sistemas de implantação de espécies de Brachiaria em consórcio com sorgo granífero na segunda safra

The grain sorghum intercropped with Brachiaria provides the production of grains and dry mass in the off-season; however, there is a lack of information related to the implantation of these species. The objective of this study was to identify the best association of sorghum and Brachiaria in the production of grain and dry matter in the Brazilian Cerrado region. The experiment was conducted in Rio Verde, State of Goiás, in the experimental design of randomized blocks, in a 2×3×4+5 factorial scheme, with four replications. Two sorghum hybrids (BRS 330 and DKB 551) associated to three Brachiaria species (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens and Brachiaria ruziziensis) were evaluated in four systems of Brachiaria implantation (row, interrow, row + interrow of sorghum and spread). Additional treatments referred to the two sorghum monocrops and the three Brachiaria species. The sorghum and Brachiaria consortium resulted in a reduction in grain yield, but the Brachiaria implantation systems in the row, interrow and spread were the most promising. The sorghum hybrid DKB 551 was the most sensitive to the competition with Brachiaria, although there were no grain yield differences in the intercropping. The Brachiaria intercropped in the interrow and in the row + interrow, mainly with B. ruziziensis, were the most promising for the production of dry mass and total crude protein. The cultivation of Brachiaria intercropped with sorghum provided a greater contribution of dry mass in the off-season, an important fact for the no-tillage system in the agricultural production systems of the Brazilian Cerrado.(AU)

O consórcio de sorgo granífero com braquiária proporciona a produção de grãos e massa seca na entressafra; contudo, há carência de informações relacionadas à implantação dessas espécies. Sendo assim, este trabalho teve por objetivo identificar a melhor associação de sorgo granífero e braquiária na segunda safra para produção de grãos e massa seca na região do Cerrado. O experimento foi conduzido em Rio Verde, Goiás, no delineamento experimental de blocos randomizados, em esquema fatorial 2×3×4+5, com quatro repetições. Foram avaliados dois híbridos de sorgo granífero (BRS 330 e DKB 551) associados a três espécies de Brachiaria (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens e Brachiaria ruziziensis) em quatro sistemas de implantação da braquiária (linha, entrelinha, linha + entrelinha do sorgo e a lanço). Os tratamentos adicionais referiam-se aos dois monocultivos de sorgo e às três espécies de braquiária. O consórcio de sorgo com braquiária ocasionou redução no rendimento de grãos, porém os sistemas de implantação da braquiária na linha, entrelinha e a lanço foram os mais promissores. O híbrido de sorgo DKB 551 foi o mais sensível à competição com a braquiária, sem, contudo, haver diferenças de rendimento de grãos em consórcio. Os consórcios das braquiárias na entrelinha e na linha + entrelinha, principalmente com a B. ruziziensis, foram os mais promissores para produção de massa seca e proteína bruta total. O cultivo de braquiária com o sorgo proporcionou maior aporte de massa seca na entressafra, fato importante para o sistema de plantio direto nos sistemas de produção agrícola dos Cerrados.(AU)

Comportamento ingestivo de novilhas de corte em pastagem de sorgo forrageiro implantada com diferentes arranjos populacionais / Ingestive behavior of heifers in sorghum implanted with different population arrangements

O objetivo do presente estudo foi avaliar os efeitos da implantação de pastagem de sorgo forrageiro com diferentes arranjos populacionais no comportamento animal e na estrutura do pasto e de suas relações. Os tratamentos foram a combinação de dois espaçamentos entrelinhas e duas densidades de sementes ha-1, sendo 22 ou 44cm entrelinhas e 12 ou 24kg de sementes ha-1. Foram utilizadas 36 novilhas, com idade e peso corporal inicial de 15 meses e 262kg, respectivamente. Os tratamentos E44D24 e E22D12 apresentaram maior tempo de pastejo (469,33 e 467,78 minutos, respectivamente). Os animais do tratamento E44D24 apresentaram menor taxa de bocado (23,99 bocados minuto-1) em relação ao tratamento E22D24 (32,45 bocados minuto-1). Os animais do tratamento E44D12 apresentaram maior número de estações alimentares minuto-1 (9,21) e maior taxa de deslocamento (11,76 passos minuto-1). O espaçamento entrelinhas de plantio de 22cm aumenta o número de bocados estação-1. O aumento na densidade de sementes (24kg ha-1) e a utilização de maiores espaçamentos entrelinhas de plantio aumentam a densidade de folhas nos estratos inferior (0-30cm) e superior (acima de 60cm) do pasto. Os tratamentos E44D12 e E22D24 apresentaram maiores quantidades de colmos no estrato superior do pasto.(AU)

The objective of the study was to evaluate the effects of sorghum pasture implantation with different population arrangements in animal behavior and pasture structure and their relationships. The treatments were the combination of two row lines and two seeds per hectare densities, 22 or 44cm between rows and 12 or 24kg ha -1 of seed. 36 heifers at 15 months of age and 262kg body weight were used. The E44D24 and E22D12 treatments showed higher time of grazing (469.33 and 467.78 minutes, respectively). The animals in E44D24 treatment had lower bit rate (23.99 bites minute -1 ) compared to treatment with E22D24, a higher bit rate (32.45 bits min -1 ). The animals in E44D12 treatment presented the largest number of stations minute -1 (9.21) and higher displacement rate (11.76 steps min -1 ). The row spacing of 22cm increases the number of bits station -1 . The increase in seed density and the use of larger planting row spacing's increase the leaf density of the lower (0-30cm) and higher stratum (above 60cm) of pasture. The E44D12 and E22D24 treatment have higher amounts of stems in the upper stratum of the pasture.(AU)

Effects of weed management and plant arrangements on yield index of sweet sorghum / Eefeito do manejo de plantas daninhas e arranjo de plantas nos índices de produtividade do sorgo sacarino

Sweet sorghum is currently an important alternative for ethanol production in sugar cane off-season. In this study was to evaluate the effects of plant arrangements and the application of atrazine and S-metolachlor on growth and productivity of sweet sorghum. An experiment was conducted in randomized block design and, arranged in split plots with four repetitions. Plots consisted of spacing (0.25 m, 0.45 m 0.45-0.45-0.90 m) and sub-plots of weed control methods - atrazine (2000 g ha-1), atrazine + S-metolachlor (2000 + 720 g ha-1), atrazine + S-metolachlor (2000 + 960 g ha-1), atrazine + S-metolachlor (2000 + 1200 g ha-1), atrazine + S-metolachlor (2000 + 1440 g ha-1). Besides that, manual hoeing control was added. The intoxication of sorghum plants and weed control was evaluated at 7, 14 e 28 days after herbicides application (DAA). Plant height, stem diameter, total fresh matter, juice mass and total soluble solids (°Brix) were evaluated at 120 days after crop emergence (DAE). There was no interaction between the factors spacings and control method for variables total matter fresh (TMF), height (H), stem diameter (D), juice mass (JM), and Brix. Application of the mixture (atrazine + S-metolachlor) in the highest doses reduced total fresh matter and °Brix. The spacing of 0.25 m provided the highest productivity of fresh matter, juice mass and increased the °Brix. The application of mixture (atrazine + S-metolachlor) controlled 90% of the weeds at 28 days after application. The increasing in doses of S-metolachlor elevates the intoxication in sorghum plants. The mixture (atrazine + S-metolachlor) has a potential for use in weed control in sweet sorghum, but at doses below 960 g ha-1 of S-metolachlor.

O objetivo desse trabalho foi avaliar os efeitos de arranjos de plantas e dos herbicidas atrazine e S-metolachlor sobre o crescimento e a produtividade do sorgo sacarino. O experimento foi realizado no delineamento em blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em esquema de parcelas subdivididas. Nas parcelas avaliaram-se os espaçamentos entrelinhas (0,25 m, 0,45 m e 0,45-0,45-0,90 m) e nas subparcelas os métodos de controle das plantas daninhas: atrazine (2000 g ha-1), atrazine + S-metolachlor (2000 + 720 g ha-1), atrazine + S-metolachlor (2000 + 960 g ha-1), atrazine + S-metolachlor (2000 + 1200 g ha-1), atrazine + S-metolachlor (2000 + 1440 g ha-1), capina manual e ausência de controle. Aos 7, 14 e 28 dias após a aplicação dos herbicidas foi avaliado a intoxicação das plantas de sorgo e o nível de controle de plantas daninhas na cultura. Aos 120 dias após a emergência da cultura avaliou-se altura de plantas, diâmetro de colmo, massa fresca total, massa de caldo e o teor de sólidos solúveis totais (Brix). Não houve interação entre os fatores espaçamentos e o método de controle para as variáveis massa fresca total (TMF), altura (H), diâmetro do caule (D), peso do suco (JM) e Brix. O controle das plantas daninhas e a intoxicação visual do sorgo aumentaram linearmente com o incremento das doses do S-metolachlor. O crescimento da cultura e os teores de Brix foram reduzidos pela aplicação da associação entre atrazine + S-metolachlor. A escolha do espaçamento de entrelinha influenciou nos componentes de rendimento da cultura. Conclui-se que, o espaçamento de 0,25 m de entrelinhas proporcionou maior produtividade de matéria fresca e de Brix do caldo. A associação entre atrazine e S-metolachlor tem potencial para o uso no controle de plantas daninhas em sorgo sacarino, em doses abaixo de 960 g ha-1 de S-metolachlor.

Accelerated aging in sorghum genotypes / Envelhecimento acelerado em genótipos de sorgo

The accelerated aging test has stood out among vigor tests. It has been used with different objectives, including as an assistance method in the selection of cultivars for plant breeding. This research aimed to analyze the effects of different exposure times to accelerated aging on the germination and vigor of sorghum seeds from different genetic sources. The experiment consisted of a completely randomized design with eight genotypes and four replications. Seeds were subject to an accelerated aging test with four exposure times (0, 24, 72, and 96 h) at a temperature of 47 °C and then evaluated by germination test (G), germination speed index (GSI), mean germination time (MGT), seedling emergence (SE), emergence speed index (ESI), and mean emergence time (MET). All genotypes presented a reduction in germination, GSI, SE, and ESI, and an increase in MGT and MET. The genotype CMX5156A had an increase in seed vigor under conditions of high temperature and relative humidity. Accelerated aging for 72 hours at 47 °C drastically reduces seed vigor. The accelerated aging test can be used to differentiate sorghum genotypes in breeding programs

teste de envelhecimento acelerado tem se destacado entre os testes de vigor, sendo utilizado com diferentes objetivos, inclusive como método assistencial na seleção de cultivares para melhoramento de plantas. Esta pesquisa teve como objetivo analisar os efeitos de diferentes tempos de exposição ao envelhecimento acelerado na germinação e vigor de sementes de sorgo de diferentes fontes genéticas. O experimento consistiu em um delineamento inteiramente casualizado com oito genótipos e quatro repetições. As sementes foram submetidas ao teste de envelhecimento acelerado com quatro tempos de exposição (0, 24, 72 e 96 h) a uma temperatura de 47 °C e avaliadas pelo teste de germinação (G), índice de velocidade de germinação (GSI), tempo médio de germinação. (MGT), emergência de plântulas (SE), índice de velocidade de emergência (ESI) e tempo médio de emergência (MET). Todos os genótipos apresentaram redução na germinação, GSI, SE e ESI, e aumento no MGT e MET. O genótipo CMX5156A apresentou sementes com maior vigor em condições de alta temperatura e umidade relativa. O envelhecimento acelerado por 72 horas a 47 °C reduz drasticamente o vigor das sementes. O teste de envelhecimento acelerado pode ser usado para diferenciar genótipos de sorgo em programas de melhoramento.

Feeding preference of Spodoptera frugiperda on different sorghum genotypes / Preferência alimentar de Spodoptera frugiperda em diferentes genótipos de sorgo

The resistance of plants to pests is a feature of great importance for agriculture, as it reduces costs with insecticides and promotes increased yield resulting in higher profits. This work aimed to evaluate the feeding preference of the Spodoptera frugiperda caterpillar by different sorghum genotypes. The experiment was carried out at the Entomology Laboratory of Universidade Estadual de Mato Grosso do Sul, at University Unit of Cassilândia, from March to June 2016. The experimental design was completely randomized with ten replicates. The treatments were composed by seven sorghum genotypes: Agromen 50A40, Agromen 50A50, DOW 1G100, DOW 1G220, DOW 1G233, XB 6022 and LG 6310. Evaluations were performed with 1st instar caterpillars. The number of caterpillars that settled in the genotypes at 5, 10, 15, 20, 25, 30, 60 minutes and 24 hours after the infestation was recorded. The feeding preference index and the fresh leaf mass consumed were estimated. The Agromen 50A40 genotype showed lower attractiveness rating for the S. frugiperda among all evaluated sorghum genotypes.(AU)

A resistência das plantas às pragas é uma característica de grande importância para a agricultura, pois reduz os custos com inseticidas e promove o aumento da produtividade, resultando em maiores lucros. Este trabalho foi desenvolvido com o objetivo de avaliar a preferência alimentar da lagarta Spodoptera frugiperda por diferentes genótipos de sorgo. O experimento foi conduzido no Laboratório de Entomologia da Universidade Estadual de Mato Grosso do Sul, na Unidade Universitária de Cassilândia, no período de março a junho de 2016. O delineamento experimental foi inteiramente ao acaso, com 10 repetições. Os tratamentos foram compostos por sete genótipos de sorgo: Agromen 50A40, Agromen 50A50, DOW 1G100, DOW 1G220, DOW 1G233, XB 6022 e LG 6310. As avaliações foram realizadas com lagartas de 1° instar. Anotou-se o número de lagartas que se estabeleceram nos genótipos aos 5, 10, 15, 20, 25, 30, 60 minutos e 24 horas após a infestação. Foi estimado o índice de preferência e a massa fresca de folha consumida. O genótipo Agromen 50A40 apresentou menor atratividade para a S. frugiperda dentre todos os genótipos de sorgo avaliados.(AU)

Genetic divergence between sweet sorghum genotypes by the WARD-MLM procedure / Divergência genética entre genótipos de sorgo sacarino pelo procedimento WARD-MLM

Sweet sorghum has the potential for use in bioethanol production as a complement to sugarcane. This work aimed to identify sweet sorghum genotypes by mixed models, using the Ward-MLM method. Trials were carried out in the 2013/2014 and 2014/2015 crop years at the experimental area of Embrapa Agropecuária Oeste, in Dourados, Mato Grosso do Sul. The experiment consisted of a randomized blocks design, with three replications, using 16 sweet sorghum genotypes from the breeding program of Embrapa Milho e Sorgo. The genotype effect was significant for all the variables analyzed, and the genotypes x environments interaction was significant for most of these variables. Estimates of genetic parameters indicate that gains with selection can be obtained for the dry mass yield of panicles and ºBrix. The Ward-MLM procedure is useful for detecting genetic divergence and clustering genotypes by simultaneously using morphological, agronomic, and molecular descriptors. In addition, this method showed that three was the ideal number of groups, according to the pseudo-F and pseudo-t2 criteria, identifying the most divergent groups. When crossed, these groups have a higher probability of generating genotypes with high yield and variability.

O sorgo sacarino apresenta potencial para utilização na produção de bioetanol em complementação à cana-de-açúcar. O objetivo deste trabalho foi identificar genótipos de sorgo sacarino via modelos mistos, usando o método Ward- MLM. O experimento foi conduzido nas safras 2013/2014 e 2014/2015, na área experimental da Embrapa Agropecuária Oeste, em Dourados, MS. O delineamento experimental utilizado foi o de blocos casualizados com três repetições. Foram avaliados 16 genótipos de sorgo sacarino oriundos do programa de melhoramento da Embrapa Milho e Sorgo. O efeito de genótipo foi significativo para todas as variáveis analisadas, e a interação genótipos x ambientes foi significativa para a maioria destas variáveis. As estimativas de parâmetros genéticos obtidas indicam que ganhos com a seleção podem ser obtidos para as variáveis rendimento da massa seca de panículas e ºBrix. O procedimento Ward-MLM é útil para detectar divergência genética e agrupar genótipos pelo uso simultâneo de descritores morfológicos, agronômicos e moleculares. Além disso, este método mostrou que três foi o número ideal de grupos, conforme os critérios do pseudo-F e pseudo-t2, identificando os grupos mais divergentes. Estes grupos, quando cruzados, apresentam maior probabilidade gerar genótipos com alta produtividade e variabilidade.

Agronomic and Yield Characteristics of Grain Sorghum as Influenced by Environment Factors and Genotype

Genotypes tested in different locations, years or planting dates often change in yield due to the response of genotypes to environmental factors such as temperature, soil fertility etc. The objectives of the present study were to evaluate the effects of environment factors on agronomic and yield characteristics of grain sorghum and to identify the most adapted B-line(s) to different environments in Egypt. Six environments with 25 sorghum B-lines were conducted at two locations (Giza and Shandaweel) in 2012 and 2013 years and two planting dates in Giza location. A randomised complete block design was used in each environment with three replications. Mean squares due to genotype × environment were significant for all studied traits. Increasing temperature from second planting date to first planting date in Giza across seasons caused the significant decrease in grain yield per plant (GYPP) by about 15.3%. This reduction in yield was associated with significant decreases in the number of grains/plant (GPP) (9.29%), plant height (PH) (7.31%) and days to 50% flowering (DTF) (6.92%). Moreover, higher temperature in 2012 than 2013 season in Shandaweel caused significant (p<0.01) reduction in GYPP by 18.04%, GPP (34.76%) and DTF (8.33%). Though the temperature was higher in Shandaweel than Giza, the increase in GYPP in Shandaweel than Giza could probably due to the better physical and chemical properties of the soil. Across all environments, the B-line BTX-TSC-20 followed by ICSB-88003 showed the highest GYPP. BTX-TSC-20 followed by ICSB-1808 under E1 and E3 environments (Giza, first planting date in 2012 and 2013), ICSB-14 and ICSB-88003 under E2 and E4 (Giza, second planting date in 2012 and 2013), ICSB-11 followed by BTX 2-1 under E5 (Shandaweel, 2012 season) and ICSB-88003 followed by ICSB-70 under E6 (Shandaweel, 2013 season) were the most adapted B-lines.

Yield Adaptability and Stability of Grain Sorghum Genotypes across Different Environments in Egypt using AMMI and GGE-biplot Models

Presence of G×E interaction reduces the correlation between genotypic and phenotypic parameters and complicates progress of selection. Among several methods proposed for evaluation of the GE interaction, the AMMI and GGE-biplot are the most informative models. The objective of this study was to estimate the G×E interaction in sorghum parental lines and to identify sorghum B-lines of stability and adaptability across different environments using the AMMI and GGE-biplot models. Six environments with 25 sorghum B-lines were conducted at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment (yield trial) with three replications. The AMMI analysis of variance indicated that the genotype (G), environment (E) and GE interaction had significant influence (p≤0.01) on sorghum grain yield. Based on AMMI model, BTX TSC-20 followed by ICSB-1808 showed both high yielding and stability across the test environments. However, ICSB-8001 (G11) and BTX-407 (G21), showed maximum stability, but with moderate grain yield. Based on GGE-biplot method, BTX TSC-20 (G25) was the winning genotype for the mega-environment which consists of E1 and E3, ICSB-14 (G3) for the mega-environment (E2 and E4), while BTX 2-1 (G20) for E5 mega-environment, ICSB-88003 (G12) and ICSB-70 (G6) for the mega-environment E6. These genotypes are the most adapted to the respective environments.

Variáveis morfogênicas e estruturais de sorgo forrageiro implantado com diferentes arranjos populacionais sob pastoreio contínuo / Morphogenetic and structural variables of sorghum implanted with different population arrangements under continuous grazing

O objetivo do estudo foi avaliar os efeitos da utilização de diferentes arranjos populacionais na implantação de sorgo forrageiro nas características morfogênicas e estruturais do pasto. Os tratamentos foram 22 ou 44cm entrelinhas e 12 ou 24kg de sementes ha-1. O método de pastoreio foi contínuo. Foram utilizadas 36 novilhas, com idade e peso corporal médios de 15 meses de 262kg. As variáveis morfogênicas não foram influenciadas significativamente (P>0,05) pelos arranjos populacionais e pelos períodos de avaliação, sendo obtidos taxa de alongamento e senescência foliar de 1,43 e 1,11cm dia-1afilho-1, respectivamente, taxa de aparecimento foliar e intervalo de surgimento de folhas de 0,28 folhas dia-1afilho-1 e 3,81 dias, filocrono e duração de vida foliar de 72,99 e 351,68 graus dia, nessa ordem. As características estruturais do pasto foram influenciadas pelos períodos de avaliação. Do primeiro para o terceiro período de avaliação, foi verificada uma redução de 65,53% no número de folhas em alongamento e de 47,79% no número de folhas vivas.(AU)

The objective of the study was to evaluate the effects of using different population arrangements in the implementation of sorghum in the morphogenetic and structural characteristics of the pasture. The treatments were 22 or 44cm between rows and 12 or 24kg ha-1 of seed. The grazing method was continuous. The sample consisted of 36 heifers with an average age of 15 months and average body weight of 262kg. Morphogenic variables were not significantly influenced (P>0.05) by population arrangements and evaluation periods, elongation rate and leaf senescence of 1.43 and 1.11cm afilho-1 day-1 being obtained, respectively, and leaf appearance rate of leaf appearance leaves the range of 0.28 day-1 and 1afilho 3.81 days, phyllochron and leaf duration of life of 72.99 and 351.68 degree day, in that order. The structural characteristics of the pasture were influenced by evaluation periods. From the first to the third evaluation period, a reduction of 65.53% in the number of leaves in stretching and 47.79% in the number of living leaves was verified.(AU)