RESUMO

Glyphosate applied at low doses can stimulate photosynthesis and yield. The objective of this study was to evaluate the application of low doses of glyphosate and sowing seasons in physiological characteristics and grain yield of common bean of early cycle. Two experiments were conducted in the field, the first in winter season and the second in wet season. The experimental design was a randomized complete block design, consisting of five and seven low doses of glyphosate and one period of application, with four replications. Glyphosate low dose of 108.0 g a.e. ha-1 impaired net CO2 assimilation rate, stomatal conductance, transpiration rate, instantaneous carboxylation efficiency, number of pods per plant, number of grains per plant and number of grains per pod. Glyphosate dose of 7.2 g a.e. ha-1 provided a 23% increase in grain yield in winter season, and the dose of 36.0 g a.e. ha-1 provided a 109% increase in grain yield in wet season. To our knowledge, this is the first report on effect of glyphosate at low doses and sowing season to obtain yield increases in common bean of early cycle.

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RESUMEN La valoración de las fuentes de variación de los análisis de varianza combinado en las pruebas de evaluación multi-ambientes es de gran importancia en la selección de genotipos para recomendar nuevos cultivares, por su adaptabilidad y estabilidad. El objetivo de esta investigación fue evaluar la significancia estadística y contribución de las fuentes de variación: ambientes, genotipos e interacción genotipo x ambiente para rendimiento de algodón-semilla, porcentaje de fibra y rendimiento de fibra, en las zonas del Caribe seco y húmedo colombiano. Se utilizaron los datos de dos pruebas multi-ambientes por zona, donde se evaluaron 10 genotipos de fibra media diferentes, bajo el diseño de bloques completos al azar, con cuatro repeticiones. Cada prueba estuvo conformada por cuatro ensayos realizados durante las cosechas 2003/2004, 2007/2008 y 2009/2010. Los resultados señalan que, en promedio, el ambiente fue la fuente de variación más importante en significancia (p <0,05 y p <0,01) y variación (>64 %), de los análisis de varianza combinado para rendimiento de algodón-semilla y fibra, con tendencia similar en su comportamiento entre ellas y en las dos zonas del Caribe colombiano. Para el porcentaje de fibra en el Caribe seco, la fuente de variación más importante fue genotipos (74,4 %) y en el Caribe húmedo fue el ambiente (57,2 %). Se sugiere subdividir las dos zonas del Caribe en subzonas más homogéneas ambientalmente o aumentar en más de cuatro el número de ensayos por prueba, para minimizar el efecto del ambiente y la interacción genotipo x ambiente.

ABSTRACT The assessment of the sources of variation of the combined analysis of variance in the multi-environment evaluation tests is of great importance in the selection of genotypes to recommend new cultivars for their adaptability and stability. The objective of this research was to evaluate the statistical significance and contribution of the sources of variation: environments, genotypes and genotype x environment interaction for cotton-seed yield, fiber percentage and fiber yield, in the dry and humid Colombian Caribbean zones. Data from two multi-environment tests per zone were used, where 10 different medium fiber genotypes were evaluated, under a randomized complete block design with four replications. Each test consisted of four experimentos carried out during the 2003/2004, 2007/2008 and 2009/2010 harvests. The results indicate that on average the environment was the most important source of variation in significance (p <0.05 and p <0.01) and variation (>64 %) of the combined analysis of variance for cotton-seed yield and fiber, with a similar trend in their behavior between them and in the two zones of the Colombian Caribbean. For the percentage of fiber in the dry Caribbean, the most important source of variation was genotypes (74.4 %) and in the humid Caribbean it was the environment (57.2 %). It is suggested to subdivide the two zones of the Caribbean into more environmentally homogeneous subzones and / or to increase the number of trials per test, to minimize the effect of the environment and the genotype x environment interaction.

RESUMO

A adoção de diferentes arranjos de plantas na cultura da soja pode promover alterações morfológicas nas plantas, o que pode influenciar a produtividade de grãos. Neste contexto, o arranjo espacial aliado ao uso de cultivares de crescimento determinado e de maior ciclo pode ser uma alternativa para o manejo da soja em condições edafoclimáticas adversas. Dessa forma o objetivo deste trabalho foi avaliar o desempenho agronômico e os componentes de produtividade da cultivar BRS Valiosa RR®, de crescimento determinado, em diferentes espaçamentos entrelinhas e populações de plantas. O ensaio foi instalado em Rio Verde/GO na safra 2012/13, no delineamento experimental de blocos casualizados em arranjo fatorial 4x4, com quatro repetições. Foram avaliados quatro espaçamentos entrelinhas (20; 40; 20/40 e 20/60 cm de entrelinhas) associados a quatro populações de plantas (200.000; 300.000; 400.000 e 500.000 plantas ha-1). A cultivar BRS Valiosa RR® apresentou potencial para redução da população de plantas sem ocasionar reduções em produtividade, independente do espaçamento entrelinhas.

The adoption of different plant arrangements in the soybean crop can promote morphological changes in the plants, which may influence the  grain yield. In this context, the spatial arrangement allied to a determined growth and higher cycle variety may be an alternative for the management of the soybean crop under adverse edaphic-climatic conditions. In this way, the objective of this work was to evaluate the agronomic performance and the productive components of the BRS Valiosa RR® soybean cultivar, with determined growth in different plant populations and between rows. The trial was installed in Rio Verde/GO at 2012/13 agricultural year. A randomized complete block design was used in a factorial arrangement 4x4 with four replications. It was evaluated four spacing between rows (20; 40; 20/40 and 20/60 cm) associated with four plant populations (200,000, 300,000, 400,000 and 500,000 ha-1 plants). The BRS Valiosa RR® cultivar showed potential to reduce the plant population without causing reductions in grain yield, regardless of the spacing between rows.

Assuntos

RESUMO

A adoção de diferentes arranjos de plantas na cultura da soja pode promover alterações morfológicas nas plantas, o que pode influenciar a produtividade de grãos. Neste contexto, o arranjo espacial aliado ao uso de cultivares de crescimento determinado e de maior ciclo pode ser uma alternativa para o manejo da soja em condições edafoclimáticas adversas. Dessa forma o objetivo deste trabalho foi avaliar o desempenho agronômico e os componentes de produtividade da cultivar BRS Valiosa RR®, de crescimento determinado, em diferentes espaçamentos entrelinhas e populações de plantas. O ensaio foi instalado em Rio Verde/GO na safra 2012/13, no delineamento experimental de blocos casualizados em arranjo fatorial 4x4, com quatro repetições. Foram avaliados quatro espaçamentos entrelinhas (20; 40; 20/40 e 20/60 cm de entrelinhas) associados a quatro populações de plantas (200.000; 300.000; 400.000 e 500.000 plantas ha-1). A cultivar BRS Valiosa RR® apresentou potencial para redução da população de plantas sem ocasionar reduções em produtividade, independente do espaçamento entrelinhas.(AU)

The adoption of different plant arrangements in the soybean crop can promote morphological changes in the plants, which may influence the  grain yield. In this context, the spatial arrangement allied to a determined growth and higher cycle variety may be an alternative for the management of the soybean crop under adverse edaphic-climatic conditions. In this way, the objective of this work was to evaluate the agronomic performance and the productive components of the BRS Valiosa RR® soybean cultivar, with determined growth in different plant populations and between rows. The trial was installed in Rio Verde/GO at 2012/13 agricultural year. A randomized complete block design was used in a factorial arrangement 4x4 with four replications. It was evaluated four spacing between rows (20; 40; 20/40 and 20/60 cm) associated with four plant populations (200,000, 300,000, 400,000 and 500,000 ha-1 plants). The BRS Valiosa RR® cultivar showed potential to reduce the plant population without causing reductions in grain yield, regardless of the spacing between rows.(AU)

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Durum wheat is the most relevant cereal for the whole of Mediterranean agriculture, due to its intrinsic adaptation to dryland and semi-arid environments and to its strong historical cultivation tradition. It is not only relevant for the primary production sector, but also for the food industry chains associated with it. In Mediterranean environments, wheat is mostly grown under rainfed conditions and the crop is frequently exposed to environmental stresses, with high temperatures and water scarcity especially during the grain filling period. For these reasons, and due to recurrent disease epidemics, Mediterranean wheat productivity often remains under potential levels. Many studies, using both linkage analysis (LA) and a genome-wide association study (GWAS), have identified the genomic regions controlling the grain yield and the associated markers that can be used for marker-assisted selection (MAS) programs. Here, we have summarized all the current studies identifying quantitative trait loci (QTLs) and/or candidate genes involved in the main traits linked to grain yield: kernel weight, number of kernels per spike and number of spikes per unit area.

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This study aimed to evaluate the effect of different levels of self-seeding Italian ryegrass (Lolium multiflorum Lam.) and nitrogen rates - applied additionally after two defoliations - on plant structure, in forage and seed yield. Levels of self-seeding were classified as very high (777 kg ha-1), high (736 kg ha-1), intermediate (624 kg ha-1), and low (234 kg ha-1). Populations were fertilized with zero, 20.25, 40.50, and 60.75 kg ha-1 of supplemental nitrogen applied after two defoliations; respectively, in very high, high, intermediate, and low levels. Higher levels of self-seeding promoted greater forage yield and uniformity of vegetation structure. Number of fertile tillers and number of seeds per plant have benefited by the combination of high self-seeding and supplemental nitrogen fertilization. Despite influencing the uniformity and amount of forage obtained in two defoliations, the very high and low self-seeding levels did not differ in Italian ryegrass seed production. However, linear addition for this same variable was obtained with the inclusion of supplemental nitrogen fertilization. In pastures from low and intermediate self-seeding levels, total dry mass increases linearly with the levels of nitrogen fertilization assessed in this research.(AU)

O objetivo deste estudo foi avaliar o efeito de diferentes níveis de ressemeadura natural de azevém anual (Lolium multiflorum Lam.), bem como, doses suplementares de nitrogênio sobre a estrutura de plantas, produção de forragem e de sementes. Os níveis de ressemeadura foram classificados como: muito elevada (777 kg ha-1); elevada (736 kg ha-1); intermediária (624 kg ha-1) e baixa (234 kg ha-1). Populações oriundas destes níveis foram fertilizadas com zero, 20.25, 40.50, and 60.75 kg ha-1 de nitrogênio, aplicado de forma suplementar após duas desfolhas. Maiores níveis de ressemeadura propiciaram maior colheita de forragem e maior uniformização da estrutura da vegetação. A quantidade de perfilhos férteis e o número de sementes por planta foram beneficiados pela combinação de elevada ressemeadura e aplicação de nitrogênio. Apesar de influenciar a uniformização e a quantidade de forragem obtida em duas desfolhas, os níveis de ressemeadura natural, muito elevada e baixa não diferiram entre si na produção de sementes no ano subsequente. Todavia, acréscimo linear para esta mesma variável foi verificado com avanço suplementar da adubação nitrogenada. Em pastagem de azevém anual proveniente dos níveis baixo e intermediário, a produção de massa seca total é acrescida linearmente com os níveis de fertilização avaliados no presente trabalho.(AU)

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Agricultural expansion requires the deployment of stress-tolerant crops like safflower (Carthamus tinctorius L.). In safflower breeding, oil improvement in early generations requires indirect selection through simply inherited traits. The oil quality is mostly related to the fatty acid profile, which is determined by the OL locus. The aim of this research was to identify simple easy-to-measure traits that indirectly explain oil content variation and its interaction with yield components, and also to generate an effective tool for genotyping the OL locus. A field experiment with F5 and pure lines was carried out to correlate the oil content with 18 traits including yield components, and phenological and morphological characteristics. KASP technology using primers designed according to the ctFAD2-1 gene sequence was applied for OL locus genotyping and validated through fatty acids phenotyping. Hull content, the length:width ratio of the grain, and plant height were identified as the most promising selection tools for increasing oil content, and grains per capitulum was the best yield component for increasing yield without decreasing the oil content. KASP genotyping successfully worked as a MAS tool, identifying oleic and linoleic genotypes. These tools enhance options for improving oil content and quality for safflower breeding.

RESUMO

ABSTRACT: This study aimed to evaluate the effect of different levels of self-seeding Italian ryegrass (Lolium multiflorum Lam.) and nitrogen rates - applied additionally after two defoliations - on plant structure, in forage and seed yield. Levels of self-seeding were classified as very high (777 kg ha-1), high (736 kg ha-1), intermediate (624 kg ha-1), and low (234 kg ha-1). Populations were fertilized with zero, 20.25, 40.50, and 60.75 kg ha-1 of supplemental nitrogen applied after two defoliations; respectively, in very high, high, intermediate, and low levels. Higher levels of self-seeding promoted greater forage yield and uniformity of vegetation structure. Number of fertile tillers and number of seeds per plant have benefited by the combination of high self-seeding and supplemental nitrogen fertilization. Despite influencing the uniformity and amount of forage obtained in two defoliations, the very high and low self-seeding levels did not differ in Italian ryegrass seed production. However, linear addition for this same variable was obtained with the inclusion of supplemental nitrogen fertilization. In pastures from low and intermediate self-seeding levels, total dry mass increases linearly with the levels of nitrogen fertilization assessed in this research.

RESUMO: O objetivo deste estudo foi avaliar o efeito de diferentes níveis de ressemeadura natural de azevém anual (Lolium multiflorum Lam.), bem como, doses suplementares de nitrogênio sobre a estrutura de plantas, produção de forragem e de sementes. Os níveis de ressemeadura foram classificados como: muito elevada (777 kg ha-1); elevada (736 kg ha-1); intermediária (624 kg ha-1) e baixa (234 kg ha-1). Populações oriundas destes níveis foram fertilizadas com zero, 20.25, 40.50, and 60.75 kg ha-1 de nitrogênio, aplicado de forma suplementar após duas desfolhas. Maiores níveis de ressemeadura propiciaram maior colheita de forragem e maior uniformização da estrutura da vegetação. A quantidade de perfilhos férteis e o número de sementes por planta foram beneficiados pela combinação de elevada ressemeadura e aplicação de nitrogênio. Apesar de influenciar a uniformização e a quantidade de forragem obtida em duas desfolhas, os níveis de ressemeadura natural, muito elevada e baixa não diferiram entre si na produção de sementes no ano subsequente. Todavia, acréscimo linear para esta mesma variável foi verificado com avanço suplementar da adubação nitrogenada. Em pastagem de azevém anual proveniente dos níveis baixo e intermediário, a produção de massa seca total é acrescida linearmente com os níveis de fertilização avaliados no presente trabalho.

RESUMO

Soybeans sowing in different plants' spatial distribution can influence the phytosanitary management of this crop and, consequently, impact on grains yield. This study was carried out to evaluate the effect of plants arrangements on infestation and control of caterpillars, the deposition of spray syrup as well as assess the agronomic performance of soybean cultivated in the Brazilian Cerrado. The assay was performed during two consecutive seasons in a randomized complete block design with four replications. Soybean cultivation was implemented in 0.50 m spacing between rows, crossed (0.50 m x 0.50 m), twin rows (0.25 m / 0.75 m), and narrow (0.25 m). In the reproductive stage of plants, both crossed and narrow arrangements showed higher caterpillars' incidence. There was a more evident risk of caterpillar incidence in arrangements that promoted better equidistance among plants. This risk was mitigated when taking into account both control and overlap of syrup, which could be incremented into inferior canopy with the enhancement of application rate. The increase in application rate from 75 to 150 L ha-1 promoted superior spray deposition volumes. Increases in grain yield was noted in the narrow arrangement.

A semeadura da soja em diferentes distribuições espaciais de plantas pode influenciar no manejo fitossanitário da cultura e consequentemente impactar na produtividade de grãos. Este estudo foi conduzido para avaliar o efeito de arranjos de plantas na infestação e controle de lagartas, deposição de calda pulverizada e no desempenho agronômico da soja cultivada no Cerrado brasileiro. Por dois anos agrícolas consecutivos, conduziu-se um ensaio de campo em delineamento de blocos casualizados com quatro repetições, com o cultivo da soja em espaçamento 0,50 m de entrelinhas de semeadura, cruzado (0,50 m x 0,50 m) em fileiras duplas (0,25 m / 0,75 m) e adensado (0,25 m). Em estádio reprodutivo das plantas, arranjos em linhas de semeadura adensadas e cruzadas foram superiores quanto a incidência de lagartas. Em igual população, há maior risco de incidência de lagartas em arranjos que proporcionem melhor equidistância entre plantas. Este risco é minimizado devido a igualdade de controle e sobreposição de calda, a qual pode ser incrementada no dossel inferior com aumento da taxa de aplicação. O aumento da taxa de aplicação de 75 para 150 L ha-1promoveu aumento na deposição no terço inferior das plantas. O arranjo em linhas adensadas mostra-se promissor para cultivo de soja.

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RESUMO

A distribuição de plantas de soja, bem como sua conjunção à determinada época de semeadura pode resultar em melhor aproveitamento da área de cultivo e, consequentemente, influenciar de maneira positiva o rendimento de grãos. Nesse âmbito, o objetivo deste trabalho foi avaliar o desempenho agronômico de cultivares de soja em espaçamento entrelinhas adensado e esse procedimento associado a épocas de semeadura distintas. Para tanto, foram realizados três ensaios de campo em duas safras agrícolas. Na safra 2014/15 foi conduzido experimento em delineamento de blocos casualizados, com 4 repetições, em arranjo fatorial 8 x 2. Os tratamentos foram constituídos pela combinação de oito cultivares de soja e dois espaçamentos entrelinhas de semeadura: tradicional e adensado (0,5 e 0,25 m, respectivamente). Na safra seguinte (2015/16), foram realizados dois experimentos, cada um com uma cultivar de soja. Utilizou-se o mesmo delineamento e quantidade de repetições, diferindo-se do experimento anterior devido à adoção de esquema de parcelas subdivididas. Nas parcelas foram alocadas três épocas de semeadura equidistantes em 15 dias, e nas subparcelas foram dispostos os espaçamentos tradicional e adensado de semeadura. Não houve diferença entre os espaçamentos entrelinhas de semeadura utilizados no experimento realizado na primeira safra, observando variação apenas entre as cultivares de soja. Cultivares com ciclo mais longo apresentam maiores produtividades. Para os experimentos realizados na segunda safra, foi verificado maior efeito das épocas de semeadura em relação ao espaçamento entrelinhas, observando maiores produtividades da soja nas semeaduras realizadas mais precocemente.

The distribution of soybean plants, as well as the conjunction to a determined sowing date can result in better use of the growing area and, consequently, influence in a positive way the grain yield. In this context, the objective of this work was to evaluate the agronomic performance of soybean cultivars in narrow row and this procedure associated to different sowing dates. Therefore, three field experiments were performed in two agriculture seasons. In the season 2014/15 an experiment was conducted in randomized completely block design, with four repetitions, in factorial arrangement 8 x 2. The combination of eight soybean cultivars and two spacing sowing between rows, traditional and narrow (0.5 and 0.25 m, respectively), composed the treatments. In the following season (2015/16), two experiment were performed, each one with a soybean cultivar. The same experimental design and number of repetition was used, differing from the anterior experiment by the adoption of split plot scheme. The three sowing dates, equidistant in 15 days, were allocated in the plots, and disposing in the subplots the traditional and narrow sowing spacing. There was no difference between spacing row used in the experiment performed in the first season, observing variation only among the soybean cultivars. Cultivars with longer crop cycle showed the greatest yields. For the experiments performed in the second season, it was verified higher effect of sowing date in relation to the spacing between rows, observing greatest soybean yields in the earliest sowing date.

Assuntos

RESUMO

A distribuição de plantas de soja, bem como sua conjunção à determinada época de semeadura pode resultar em melhor aproveitamento da área de cultivo e, consequentemente, influenciar de maneira positiva o rendimento de grãos. Nesse âmbito, o objetivo deste trabalho foi avaliar o desempenho agronômico de cultivares de soja em espaçamento entrelinhas adensado e esse procedimento associado a épocas de semeadura distintas. Para tanto, foram realizados três ensaios de campo em duas safras agrícolas. Na safra 2014/15 foi conduzido experimento em delineamento de blocos casualizados, com 4 repetições, em arranjo fatorial 8 x 2. Os tratamentos foram constituídos pela combinação de oito cultivares de soja e dois espaçamentos entrelinhas de semeadura: tradicional e adensado (0,5 e 0,25 m, respectivamente). Na safra seguinte (2015/16), foram realizados dois experimentos, cada um com uma cultivar de soja. Utilizou-se o mesmo delineamento e quantidade de repetições, diferindo-se do experimento anterior devido à adoção de esquema de parcelas subdivididas. Nas parcelas foram alocadas três épocas de semeadura equidistantes em 15 dias, e nas subparcelas foram dispostos os espaçamentos tradicional e adensado de semeadura. Não houve diferença entre os espaçamentos entrelinhas de semeadura utilizados no experimento realizado na primeira safra, observando variação apenas entre as cultivares de soja. Cultivares com ciclo mais longo apresentam maiores produtividades. Para os experimentos realizados na segunda safra, foi verificado maior efeito das épocas de semeadura em relação ao espaçamento entrelinhas, observando maiores produtividades da soja nas semeaduras realizadas mais precocemente.(AU)

The distribution of soybean plants, as well as the conjunction to a determined sowing date can result in better use of the growing area and, consequently, influence in a positive way the grain yield. In this context, the objective of this work was to evaluate the agronomic performance of soybean cultivars in narrow row and this procedure associated to different sowing dates. Therefore, three field experiments were performed in two agriculture seasons. In the season 2014/15 an experiment was conducted in randomized completely block design, with four repetitions, in factorial arrangement 8 x 2. The combination of eight soybean cultivars and two spacing sowing between rows, traditional and narrow (0.5 and 0.25 m, respectively), composed the treatments. In the following season (2015/16), two experiment were performed, each one with a soybean cultivar. The same experimental design and number of repetition was used, differing from the anterior experiment by the adoption of split plot scheme. The three sowing dates, equidistant in 15 days, were allocated in the plots, and disposing in the subplots the traditional and narrow sowing spacing. There was no difference between spacing row used in the experiment performed in the first season, observing variation only among the soybean cultivars. Cultivars with longer crop cycle showed the greatest yields. For the experiments performed in the second season, it was verified higher effect of sowing date in relation to the spacing between rows, observing greatest soybean yields in the earliest sowing date.(AU)

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Yield under water stress (YS) is used as the main criterion in the selection of wheat varieties for dry Mediterranean environments. It has been proposed that selection of genotypes using YS assisted by morphological and physiological traits associated with YS is more efficient in selecting high yielding genotypes for dry environments. A study was carried out at the Antumapu Experiment Station of the University of Chile, located in Santiago, Chile (33° 40'S and 70° 38' W). The objective was to evaluate the extent to which morpho physiological traits could explain YS. For this purpose, grain yield and yield components of 185 durum wheat genotypes from ICARDA (International Center for Agricultural Research in the Dry Areas) and INIA (Chilean National Institute for Agricultural Research) were evaluated along with seed size and weight, days to heading (DH), glaucousness (GLAU), plant height (PH) and 13C discrimination (Δ). The design was an α-lattice with two replications, the genotypes were grown in two different water conditions (high and low irrigation) during two seasons (2011-2012/2012-2013). Grain weight (GW) was the only yield component with high H associated with YS, but it was not associated with yield under high irrigation (YI). The combination of YI with DH+GLAU+PH+Δ+GW obtained in LI environments explained a greater fraction of YS (38%) across years; these traits had lower genotype x environment interaction than YS, they also explained a higher proportion of yield under drought than YI. None of the traits studied could replace YS in selections for grain yield. It is concluded that these traits could aid in the selection of durum wheat subject to water stress, particularly in early generations.

RESUMO

An increase in the land area dedicated to super-high density olive orchards has occurred in Chile in recent years. Such modern orchards have high irrigation requirements, and optimizing water use is a priority. Moreover, this region presents low water availability, which makes necessary to establish irrigation strategies to improve water productivity. An experiment was conducted during four consecutive growing seasons (2010-2011 to 2013-2014) to evaluate the responses of yield and water productivity to irrigation cut-off strategies. These strategies were applied after fruit set using midday stem water potential (Ψstem) thresholds in a super-high density olive orchard (cv. Arbequina), located in the Pencahue Valley, Maule Region, Chile. The experimental design was completely randomized with four irrigation cut-off treatments based on the Ψstem thresholds and four replicate plots per treatment (five trees per plot). Similar to commercial growing conditions in our region, the Ψstem in the T1 treatment was maintained between -1.4 and -2.2 MPa (100% of actual evapotranspiration), while T2, T3 and T4 treatments did not receive irrigation from fruit set until they reached a Ψstem threshold of approximately -3.5, -5.0, and -6.0 MPa, respectively. Once the specific thresholds were reached, irrigation was restored and maintained as T1 in all treatments until fruits were harvested. Yield and its components were not significantly different between T1 and T2, but fruit yield and total oil yield, fruit weight, and fruit diameter were decreased by the T3 and T4 treatments. Moreover, yield showed a linear response with water stress integral (SΨ), which was strongly influenced by fruit load. Total oil content (%) and pulp/stone ratio were not affected by the different irrigation strategies. Also, fruit and oil water productivities were significantly greater in T1 and T2 than in the T3 and T4. Moreover, the T2, T3, and T4 treatments averaged 37, 51, and 72 days without irrigation which represented 75-83, 62-76, and 56-70% of applied water compared with T1, respectively. These results suggest that using the T2 irrigation cut-off strategy could be applied in a super-high density olive orchard (cv. Arbequina) because it maintained yields, saving 20% of the applied water.

RESUMO

ABSTRACT The use of genetic divergence as a basis for identifying superior individuals, with greater heterozygosity, is important in view of the difficulty when selecting of dissimilar genotypes exhibiting high average for interest traits. The aim of this study was to evaluate the genetic divergence and the expression of seed production traits in seventeen apomictic Paspalum plicatulum × Paspalum guenoarum hybrids and two male parents (P. guenoarum). A randomized block design was used, with genotypes individually arranged into ten blocks. The following traits were assessed: total number of tillers/plant (TT), reproductive tiller/plant (RT), number of racemes per inflorescence (NRI), reproductive tiller height (RTH), inflorescence rachis length (IRL), number of seeds/inflorescence (NSI), weight of a thousand seeds (WTS) and seed production (SP). Genetic divergence among the genotypes was estimated using the Tocher method and UPGMA clustering, based on the generalized Mahalanobis distance (D2 ii'). The Tocher and UPGMA optimization methods showed high concordance. The traits that most contributed to genetic divergence were RTH (23.59%), IRL (21.63%), WTS (16.67%) and SP (14.23%). The presence of genetic diversity made it possible to identify divergent genotypes and those with high means for the traits studied, allowing the selection of genotypes with significant breeding potential. Repeated cross-breeding of female superior plants with the genotypes Azulão and H20 can result in a high heterosis effect on seed production characteristics.

RESUMO A utilização da divergência genética como base para a identificação de indivíduos superiores, com maior heterozigose, é importante diante da dificuldade de escolha de genótipos dissimilares, que apresentem média elevada para as características de interesse. O objetivo deste trabalho foi avaliar a divergência genética e a expressão dos caracteres da produção de sementes de dezessete híbridos apomíticos de Paspalum plicatulum × Paspalum guenoarum e dois genitores masculinos (P. guenoarum). O delineamento experimental utilizado foi o de blocos casualizados, com os genótipos arranjados individualmente em dez blocos. Foram avaliadas as seguintes características: total de perfilhos/planta (TP), perfilhos reprodutivos/planta (PR), número de racemos/inflorescência (NRI), altura dos perfilhos reprodutivos (APR), comprimento de inflorescência (CI), número de sementes/inflorescência (NSI), peso de mil sementes (PMS) e produção de sementes (PS). A divergência genética entre os genótipos foi estimada pelos métodos de agrupamento de Tocher e UPGMA, com emprego da distância generalizada de Mahalanobis (D2 ii'). Os métodos de otimização de Tocher e UPGMA foram concordantes entre si. As características APR (23,59%), CI (21,63%), PMS (16,67%) e PS (14,23%) foram as que mais contribuíram para a divergência genética. A presença de variabilidade genética permitiu a identificação de genótipos divergentes e com médias elevadas para os caracteres estudados, o que possibilita selecionar genótipos com elevado potencial para fins de melhoramento genético. O cruzamento repetido de plantas sexuais superiores com os genótipos Azulão e H20 pode proporcionar efeito heterótico elevado nos caracteres da produção de sementes.

RESUMO

Winter wheat (Triticum aestivum) is cultivated across a wide region; however, water is scarce during the growing season of wheat in the Northern Plain of China. Therefore, winter wheat should be irrigated to maintain a stable and high grain yield. The aim of this field study was to develop a water-conserving precision planting pattern for winter wheat that is grown in the Northern China Plain with the purpose of exploring the benefits in maintaining water and effects on wheat productivity. To accomplish this, several production variables and photosynthetic indexes were measured, including the number of stems, the leaf area index (LAI), photosynthetically available radiation (PAR), net photosynthetic rate, and grain yield. The study was carried out during the 2011­2012 and 2012­2013 winter wheat growing seasons. The experiment included a double-row planting pattern (DRPP) and a single-row planting pattern (SRPP), both of which were either irrigated or rainfed. The area of each plot was 9 m2, and the experimental design was a randomized blocks design with three replicates. All results were analyzed with an ANOVA, the F test, and the LSD (p 0.05) for means comparison. PAR capture ratios in the DRPP were higher than those in the SRPP at 50­120 cm above the ground. The photosynthetic traits of flag leaves under irrigated conditions were not significantly influenced by the respective planting pattern. However, at a growth stage of 80 under the rainfed conditions, the mean photosynthetic rate within flag leaves in the DRPP was higher than that in the SRPP. Furthermore, the DRPP under rainfed conditions was more likely to increase the apparent quantum yield (AQY) of flag leaves than the yield obtained under irrigation. These results suggest that DRPP optimizes the canopy PAR distribution in winter wheat and contributes to the maintenance of a higher photosynthetic capacity in the flag leaves under water stress (the rainfed condition). This relationship may be applied in demonstration trials to encourage winter wheat farmers to incorporate the use of DRPP in the drought-prone areas, which are subjected to insufficient precipitation during the growing stage of wheat in Northern China.

O trigo de inverno (Triticum aestivum) é cultivado em uma vasta região; no entanto, a água é escassa durante a estação de crescimento do trigo na Planície do Norte da China. Assim, o trigo de inverno deve ser irrigado para manter um rendimento de grãos estável e elevado. O objetivo deste trabalho de campo foi o de desenvolver um padrão de plantação de precisão que conserve a água para o trigo de inverno que é cultivado na Planície do Norte da China com o propósito de explorar os benefícios da retenção de água e os efeitos na produtividade do trigo. Para isso, diversas variáveis de produção e índices fotossintéticos foram medidos, incluindo o número de hastes, o índice de área da folha (do inglês, LAI - leaf area index), a radiação fotossinteticamente disponível (do inglês, PAR - photosynthetically available radiation), taxa fotossintética líquida e o rendimento de grãos. O estudo foi conduzido durante as estações de crescimento do trigo de inverno em 2011-2012 e 2012-2013. O experimento incluiu um padrão de plantação em fila dupla (do inglês, DRPP - double-row planting pattern) e um padrão de plantação em fila única (do inglês, SRPP - single-row planting pattern), em ambos os casos ou foram irrigados artificialmente ou através da chuva (regadio e sequeiro). A área de cada lote de terra foi de 9 m2, e o delineamento experimental foi um de blocos aleatórios com três repetições. Todos os resultados foram analisados com uma ANOVA, um teste F, e um LSD (p 0.05) para a comparação das médias. As taxas de captura de PAR no DRPP foram maiores do que aquelas no SRPP a 50-120 cm acima do solo. As características fotossintéticas das folhas-bandeira (do inglês, flag leaves) sob condições de irrigação artificial não foram significativamente influenciadas pelo respectivo padrão de plantação. No entanto, num estágio de crescimento de 80% abaixo das condições de irrigação pela chuva, a taxa fotossintética média dentre as folhas-bandeira no DRPP foi maior que aquela observada no SRPP. Além disso, o DRPP sob condições de irrigação pela chuva foi mais suscetível ao aumento do rendimento quântico aparente (do inglês, AQY - apparent quantum yield) das folhas-bandeira do que o rendimento obtido através da irrigação artificial. Estes resultados sugerem que o DRPP otimiza a distribuição PAR do dossel no trigo de inverno e contribui para a manutenção de uma maior capacidade fotossintética nas folhas bandeira sob estresse hídrico (a condição de sequeiro). Esta relação pode ser aplicada em ensaios de demonstração para encorajar os agricultores de trigo de inverno a incorporar o uso do DRPP em áreas propensas à seca, que estão submetidas a precipitação insuficiente durante a fase de crescimento do trigo no Norte da China.

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RESUMO

La quinua Chenopodium quinoa Willd. es una planta dicotiledónea, considerada un pseudocereal, por las características del cultivo y formas de consumo, que ha pasado a ser de interés mundial en los últimos años, debido a su alta calidad nutritiva y de amplia adaptación ecológica. Con el objetivo de aportar al conocimiento del cultivo, se evaluaron características de rendimiento, de calidad, de variación morfológica y de desarrollo fenológico, de tres accesiones de quinua, denominadas Piartal, Nariño y Bolivia. El estudio, se llevó a cabo en la sede El Remanso de la Universidad de Ciencias Aplicadas y Ambientales U.D.C.A, ubicada en el norte de Bogotá, con coordenadas geográficas 4°35' latitud norte y 74°04' longitud oeste. La evaluación fue realizada durante un ciclo de producción. Los resultados indicaron diferencias en rendimiento por planta, contenido de proteína, características morfológicas de la coloración del tallo, forma de la panoja y madurez fisiológica. El rendimiento promedio varió entre 140,09 a 260,74g por planta; los mayores rendimientos se presentaron en la accesión Piartal que, a su vez, reveló el desarrollo fenológico más corto, de seis meses. Las accesiones evaluadas mostraron alta homogeneidad fenotípica al interior de cada material, lo que permite su uso en cultivos comerciales directamente y también como parental, para hibridación dentro de programas de mejoramiento genético.

Quinoa, Chenopodium quinoa Willd. is a dicotyledoneous plant, considered a pseudocereal, according to growth characteristics and forms of consume, has become of worldwide interest in recent years due to its high nutritional quality and wide ecological adaptation. In order to contribute to the knowledge of the crop, performance characteristics, quality, morphological variation and phenological development of three accessions of quinoa, Piartal, Nariño and Bolivia were evaluated. The study was conducted under conditions of the U.D.C.A, located in the north of Bogotá, with geographical coordinates 4° 35' latitude north and 74° 04' latitude west during a production cycle. The results showed differences in plant yield, protein content, and stem color characteristics, panicle shape and physiological maturity. The yield ranged from 140.09 to 260,74g per plant, the highest yield was obtained with the Piartal accession, which also showed the shortest phenological development, six months. The accessions evaluated showed high phenotypic homogeneity within materials, allowing its direct use in commercial crops, as well as parentals for hybridization in breeding programs.

RESUMO

RESUMO: Em decorrência da instabilidade da produtividade das principais culturas associada ao déficit hídrico, tem se tornado cada vez mais frequente a necessidade do uso de tecnologias como a irrigação e a agricultura de precisão (AP). O presente trabalho objetivou avaliar a variabilidade espacial da produtividade de grãos de milho e sua correlação com variáveis explicativas de planta em área irrigada. O estudo foi conduzido nas safras agrícolas 2010/2011 e 2011/2012, em área de 35ha, manejada em sistema plantio direto e irrigação por pivô central. Os componentes de produtividade e a produtividade de grãos foram avaliados seguindo uma malha amostral de 100x100m. A produtividade de grãos e a maior parte dos componentes de produtividade apresentaram baixa dispersão dos dados, condicionando a normalidade dos dados. A produtividade de grãos, mesmo com a irrigação, apresentou elevada variabilidade espacial. Na análise de trilha, verificaram-se altos coeficientes de determinação dos componentes de produtividade com a produtividade de grãos.

ABSTRACT: Due to yield instability of main crops associated to drought, the use of technologies such irrigation and precision agriculture (PA) have been recently adopted in large scale. This study had the objective to assess the spatial variability of corn yield and its correlation with explanatory plant variables in an irrigated field. The study was carried out during the growing seasons 2010/2011 and 2011/2012, in an area of 35ha managed under no-till and center-pivot irrigation. Corn yield and yield components were evaluated following a sampling grid of 100x100m. Grain yield and most yield components showed low dispersion data, resulting in data normality. Even under irrigation, corn yield showed high spatial variability. In path analysis, it was found high determination coefficients of corn yield with yield components.

RESUMO

This study aimed to evaluate five corn varieties for baby corn yield and post-harvest quality under organic crop. The experimental design was completely randomized with four replications to evaluate the yield components and post-harvest of the studied product in 5 x 2 x 4 factorial, five varieties (IPR 114, PC 0402, PC 0404, BR 106 and BRS Angela) and two conditioning ways in the refrigerator (with and without straw) and four storage periods (0, 4, 8 and 12 days). Yield components such as spikes number per plant, plant height, height first spike, spike length without straw and with straw, spike diameter with straw and without straw, spike with straw weight and without straw, baby corn yield with straw and without straw, commercial production of baby corn without straw, commercial yield of baby corn were evaluated. For its post-harvest of product were analyzed weight loss and color parameters (L*, a*, b*, C* and H*) in 0, 4, 8 and 12 day storage periods. The results showed that the varieties were classified according to the commercial standards for both diameter and length. Thus, PC 0404 was the most suitable for obtaining baby corn. The PC 0402 showed the best results for color parameters L*, a*, b*, C*, H* and the lowest weight loss during storage periods.

Este estudo teve por objetivo avaliar cinco variedades de milho para produção de minimilho e qualidade pós-colheita em sistema orgânico de cultivo. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições para avaliação dos componentes de produção e para pós-colheita do produto, em arranjo fatorial 5 x 2 × 4, sendo as cinco variedades (IPR 114, PC 0402, PC 0404, BR 106 e BRS Ângela) e dois modos de acondicionamento (com palha e sem palha) e tempo de armazenamento (0, 4, 8 e 12 dias) dispostos no delineamento inteiramente casualizado com quatro repetições. Componentes de produção tais como: números de espigas por planta, altura de planta, altura de inserção da primeira espiga, comprimento de espiga sem palha e com palha, diâmetro de espigas com palha e sem palha, massa de espigas com palha e sem palha, produtividade de minimilho com palha e sem palha, produção comercial de minimilho sem palha, rendimento de minimilho comercial foram avaliados e para a pós-colheita do produto foram analisadas: perda de massa e parâmetros de cor (L*, a*, b*, C* e H*) nos tempos de armazenamento 0, 4, 8 e 12 dias. Os resultados obtidos permitiram concluir que as variedades estudadas foram classificadas dentro dos padrões comerciais para diâmetro e comprimento, sendo a PC 0404 a mais indicada para obtenção de minimilho e a PC 0402 a variedade que apresentou melhores resultados para os parâmetros de cor L*, a*, b*, C*, H* e menor perda de massa ao longo do período armazenado.

Assuntos

RESUMO

Em decorrência da instabilidade da produtividade das principais culturas associada ao déficit hídrico, tem se tornado cada vez mais frequente a necessidade do uso de tecnologias como a irrigação e a agricultura de precisão (AP). O presente trabalho objetivou avaliar a variabilidade espacial da produtividade de grãos de milho e sua correlação com variáveis explicativas de planta em área irrigada. O estudo foi conduzido nas safras agrícolas 2010/2011 e 2011/2012, em área de 35ha, manejada em sistema plantio direto e irrigação por pivô central. Os componentes de produtividade e a produtividade de grãos foram avaliados seguindo uma malha amostral de 100x100m. A produtividade de grãos e a maior parte dos componentes de produtividade apresentaram baixa dispersão dos dados, condicionando a normalidade dos dados. A produtividade de grãos, mesmo com a irrigação, apresentou elevada variabilidade espacial. Na análise de trilha, verificaram-se altos coeficientes de determinação dos componentes de produtividade com a produtividade de grãos.(AU)

Due to yield instability of main crops associated to drought, the use of technologies such irrigation and precision agriculture (PA) have been recently adopted in large scale. This study had the objective to assess the spatial variability of corn yield and its correlation with explanatory plant variables in an irrigated field. The study was carried out during the growing seasons 2010/2011 and 2011/2012, in an area of 35ha managed under no-till and center-pivot irrigation. Corn yield and yield components were evaluated following a sampling grid of 100x100m. Grain yield and most yield components showed low dispersion data, resulting in data normality. Even under irrigation, corn yield showed high spatial variability. In path analysis, it was found high determination coefficients of corn yield with yield components.(AU)

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RESUMO

Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

Assuntos