Pod Insertion Height Research Articles

Genome-Wide Association for Morphological and Agronomic Traits in Phaseolus vulgaris L. Accessions.

Exploring genetic resources through genomic analyses has emerged as a powerful strategy to develop common bean (Phaseolus vulgaris L.) cultivars that are both productive and well-adapted to various environments. This study aimed to identify genomic regions linked to morpho-agronomic traits in Mesoamerican and Andean common bean accessions and to elucidate the proteins potentially involved in these traits. We evaluated 109 common bean accessions over three agricultural years, focusing on traits including the grain yield (YDSD), 100-seed weight (SW), number of seeds per pod (SDPD), number of pods per plant (PDPL), first pod insertion height (FPIH), plant height (PLHT), days to flowering (DF), and days to maturity (DPM). Using multilocus methods such as mrMLM, FASTmrMLM, FASTmrEMMA, ISIS EM-BLASSO, and pLARmEB, we identified 36 significant SNPs across all chromosomes (Pv01 to Pv11). Validating these SNPs and candidate genes in segregating populations is crucial for developing more productive common bean cultivars through marker-assisted selection.

Boron Fertilization Improves the Agronomic Performance of Soybean Genotypes in the Brazilian Cerrado

Currently, Brazil is the largest producer and exporter of soybeans in the world. Most of this cultivation is concentrated in the Cerrado region, which has soils with low boron levels. Boron performs functions that are directly linked to plant performance. The objective of this study was to evaluate the agronomic performance of soybean cultivars with and without boron fertilization. Two field experiments were carried out in the agricultural years 2018/2019 and 2019/2020. Each experiment was carried out in a randomized block design with four replications and 10 soybean cultivars (Desafio, Foco, Bonus, Maracaí, 7067, 7110, 7739, 8372, 7100, and Population). Boron fertilization was carried out at the V3 stage of the crop using ulexite (10% of boron) at a rate of 3194 kg ha−1 and 0.0 kg ha−1 of B. The application of boron to the soil increased plant height, pod insertion height, number of branches, main stem diameter, and number of pods per plant, in addition to increasing the cycle of these cultivars. The cultivars 7110, 7739 and Desafio did not statistically differ in terms of grain yield in response to boron fertilization. The cultivars Foco, Bonus, Maracaí, 7067, 8372, 7100, and Population responded favorably to this fertilization. Furthermore, genetic breeding programs incorporate advanced strategies, such as the use of boron fertilization, in order to improve the performance of the selected genotypes. Implementing boron fertilization as an integral part of breeding programs helps not only to achieve high-yielding cultivars but also to optimize key agronomic traits. This integrated approach not only boosts breeding research but also provides a solid basis for sustainable and efficient agricultural practices.

Correlations of agronomic characteristics of soybean cultivated with the use of organomineral fertilizers

The use of correlations can identify the traits correlated with soybean grain yield. Therefore, the objective of this study is to use path analysis to examine how agronomic traits influence grain yield in soybeans, taking into account different doses and sources of organominerals used in cultivation. The experimental design used was randomized blocks arranged in a sub-subdivided plot with three replications. In the plots, the treatments consisted of two soybean cultivars (BMX Bônus IPRO and BMX Olimpo IPRO), and in the subplot, the treatments consisted of three phosphate fertilizers [two organomineral fertilizers manufactured and a phosphate fertilizer (simple superphosphate)]. The subplot used doses of 0 (control), 50, and 100 kg ha-1 of P2O5. At full flowering, the relative chlorophyll index was evaluated. At physiological maturity, plant height, first pod insertion height, number of stems, pod number, number of grains per pod, thousand-grain mass, and grain yield were evaluated. The plant height variable presented the greatest positive direct effect on the soybean yield cultivated using organomineral fertilizers.

Spectral variables as criteria for selection of soybean genotypes at different vegetative stages

Understanding the association between variables obtained by multispectral imaging, such as plant canopy reflectance at different wavelengths and vegetation indices (VIs), and agronomic traits of interest for soybean is crucial for breeding programs. This approach, associated with the evaluation of the best stage for spectral data collection, can identify easier-to-measure variables to be used in the indirect selection of genotypes for more expensive-to-measure traits or those that are expressed later, resulting in a faster, labor-saving, and large-scale selection process. The hypothesis of this study is the possibility of identifying promising variables for the selection of soybean genotypes through the use of vis and that different times of collection of information regarding reflectance interfere in the selection responses. Thus, our objectives were: i) to estimate heritability (h2) for agronomic traits and VIs; ii) to estimate the gains with direct selection (DS) on the VIs and indirect selection (IS) for the agronomic traits selected by the higher heritability; iii) to estimate correlations between spectral variables, VIs, and agronomic traits; iv) to identify the most promising populations for the evaluated variables; and vi) to identify the most adequate phenological stage for spectral data collection. We installed a field experiment in a randomized block design with four repetitions, 28 F3 soybean populations, and four control treatments. Agronomic traits evaluated were: days to maturity (DM), plant height (PH), first pod insertion height (PIH), number of branches (NB), and grain yield (GY). Spectral collections were performed at the V8 (45 days after emergence), R1 (60 days after emergence) and R5 (80 days after emergence) stages. Correlations between agronomic traits, reflectance at 790 nm (near-infrared), 735 nm (RedEdge), 660 nm (red), 550 nm (green), and 450 nm (blue) wavelengths, and VIs were estimated. The heritability were estimated for agronomic traits and VIs. Our findings reveal that it is possible to select soybean genotypes using spectral variables based on heritability and phenotypic aspects. Enhanced vegetation index (EVI) and soil-adjusted vegetation index (SAVI) have high heritability values (>75%) at V8. It is possible to obtain satisfactory selection gains for agronomic traits, especially GY, based on selection on EVI and SAVI at V8 stage. By this approach, the F3 segregating populations that provided the highest selection gains were P7, P8, P9, P14, P27, and P28. Spectral data collection at V8 stage provided higher h2 for VIs and agronomic traits, while R5 is the most suitable stage for estimating associations between VIs and agronomic traits.

Vegetative and productive characteristics of soybean under doses of boron and inoculation of Trichoderma atroviride

The application of new management techniques with the objective of implementing in agriculture, such as the use of growth-promoting and/or plant-protecting microorganisms and micronutrients, appears as an alternative. Thus, the aim of the study was to evaluate the potential of Trichoderma atroviride in association with doses of B, analyzing the effects on nutritional contents, yield components and productivity. The study was carried out in the field, in a randomized block design in a 4 × 5 factorial scheme, whose treatments were combined, consisting of foliar application of T. atroviride in three phenological stages (V5, R1 and R5) and no application (SEM), and five doses of B (0, 500, 1000, 1500 and 2000 g ha-1). The data obtained were submitted to ANOVA and, when significant, the study of polynomial regression and Tukey’s test was carried out, followed by Pearson’s linear correlation analysis (p < 0.05). The use of the microorganism and doses of B did not result in a significant increase in the growth and productive yield of soybean (Glycine max (L.) Merr.), but the application of the micronutrient significantly increased the number of pods per plant and the foliar content of B. Positive correlations were observed between plant height and pod insertion height (r = 0.51***), pod with branches (r = 0.68***), grains with branches and pod (r = 0.69*** and 0.95*** respectively), as well as a negative correlation between 100-grain mass and plant height (r = -0.24*), and a non-correlation for yield and leaf content of B.

SOYBEAN BASE FERTILIZATION: CHEMICAL AND MICROBIOLOGICAL SOIL INDICATORS AND CROP YIELD

Recent research suggests that soybean yield could be doubled in Brazilian conditions, implying that the base fertilization is pivotal, as it might influence chemical and microbiological soil indicators and, hence, the crop grain yield. The current study had the goal of assessing alterations in the chemical and microbiological soil indicators, in the short term, as well as the soybean biometric and grain yield performance as a function of different fertilizers for base fertilization, in two sowing periods. An experiment comprised of two sowing periods was carried out in the 2019/2020 season on a dystrophic Red Latosol, in north Parana state. Five treatments were assessed, comprising: 1) control; 2) mineral fertilizer; 3) organomineral fertilizer; 4) mineral fertilizer mixed with granulated gypsum; and 5) slow release mineral fertilizer. A randomized block design with four replicates was adopted. The following variables were assessed: chemical and microbiological soil indicators; final stand; first pod insertion height; plant height; stem diameter; number of pods per plant; number of grains per plant; number of grains per pod; grain mass per plant; and one thousand grain mass and grain yield. There is no base fertilization effect on the chemical soil indicators in the short term, however, there is an effect on the microbiological soil indicators. Soybean biometric and grain yield performance is decreased with the delayed sowing period, regardless of the type of fertilizer utilized for base fertilization. Analyzing a set of soil quality indicators enables precise and judicious results to be gathered on management practices in the soil environment.

Assessment of the Physiological Response and Productive Performance of Vegetable vs. Conventional Soybean Cultivars for Edamame Production

Because there is a close relationship between plant physiological response and crop performance, the current study aims to evaluate the photosynthetic efficiency and productive performance of vegetable versus conventional soybean cultivars for edamame production. The study was conducted at the School of Agriculture (FCA UNESP), Botucatu-SP, Brazil. The treatments in this study included soybean cultivars: vegetable-type BRS 267, vegetable-type BRSMG 790A), and type soybean cultivar grain 58HO124 EP RR, with ten repetitions per treatment in a completely randomized block design. Gas exchange and the response of the cultivars to light were evaluated for photosynthetic characterization. The first pod insertion height, plant height, number of pods per plant, and production in immature grains were all assessed for cultivar productive performance. The type of soybean cultivar grain and vegetable types of soybean showed different behaviors on physiology and yield. The vegetable-types BRS 267 and BRSMG 790A had the highest average for first pod insertion height. The vegetable type BRS 267, whose photoassimilates were designated for vegetative development, had the greatest average plant height. The conventional type 58HO124 EP RR showed greater assimilation of CO2; however, the photoassimilates were directed to floral emission because such features are inherent in its ability. Finally, vegetable-type BRSMG 790A produced the most immature grains per plant while also having the greatest first pod insertion height, being the best in converting photoassimilates for edamame production.

YIELD TRAITS OF SOYBEAN CULTIVATED UNDER BRACHIARIA AND MILLET STRAW AND POTASSIUM DOSES

There are many doubts about which straw-supplying species should be cultivated in a no-tillage system and which potassium doses are adequate for the Cerrado soils. Therefore, the current study aimed to evaluate the agronomic traits (plant height, first pod insertion height, and stem diameter); yield traits (number of pods per plant, number of grains per pod, and 100-grain weight), grain yield (kg ha-1) and potassium content in the leaves, in the production of soybean cultivated in different straws and potassium doses in two crop seasons under Cerrado conditions in the region of Ceres, Goiás, Brazil. Two types of straw (Brachiaria and millet) and four potassium doses were evaluated. A randomized complete block design arranged in a 2x2x4 factorial scheme with four repetitions was used. Two crop seasons (2011/2012 and 2012/2013), two types of straw (Millet and Brachiaria), and four potassium doses (0, 30, 60, and 90 kg ha-1 of K2O using KCl as source) were evaluated. Phosphate fertilization was performed using 400 kg ha-1 of simple superphosphate, and the cultivar used was P98Y12. The largest plant height values were obtained by applying 90 kg ha-1 of K2O. The Brachiaria straw promoted a grain yield increase associated with the potassium doses increment. The highest grain yield was 4,353.90 kg ha-1, achieved by applying 65 kg ha-1 of K2O using millet straw. The highest grain yield reached was at the rate of 90 kg ha-1 of K2O, resulting in 5,208 kg ha-1. The greatest K accumulation in the leaf is provided by Brachiaria straw.

Agronomic performance of soybean in crop rotation systems

Crop rotation consists of alternating plant species cultivation in the same agricultural land, aiming to provide nutrient replenishment in the soil through organic matter deposition, as well as mitigating the soil degradation caused by agricultural practices. However, due to the short list of known crops suitable for such application, a selection of species to be inserted to the system is of critical importance. The objective of this research was to study the agronomic performance of soybean in crop rotation systems. The experiment was conducted at the Experimental Farm of the Faculty of Agricultural Sciences of UFGD, Dourados-MS, in two cropping seasons: 2013/2014 and 2014/2015; using a randomized block design with thirteen treatments and four replications. Treatments consisted of crop rotation systems in two soybeans cropping seasons. Corn, brachiaria, canola, wheat, forage turnip, safflower, crotalaria, niger, crambe, white oat, vetch and sunflower were the selected species to be inserted in the rotation systems. Six variables were analyzed: plant height, height of first pod insertion, number of branches per plant, number of pods per plant, mass of 1000 grains and grain yield. All collected data was submitted to analysis of variance and the means comparisons were analyzed by the Scott-Knott test (5%). This study revealed that crop rotation is an agricultural technique that favors the grain yield of soybean. Furthermore, during autumn and winter, fallowing is not recommended for soybean cultivation

Soybean seed size: how does it affect crop development and physiological seed quality?

Abstract: The size of soybean seeds needs further study because its relationships with physiological quality, field establishment, and yield are controversial. The aim of this study was to evaluate the effects of seed size on soybean establishment and seed physiological quality. In the field, a 2x3x3 factorial design was used, with two cultivars (M 5947 IPRO and 59HO124 IPRO), three seed sizes (5.5, 6.0, and 6.5 mm), and three sowing densities (280,000, 320,000, and 360,000 plants.ha-1). Agronomic traits and grain yield were evaluated. After harvest, only seeds from plots with a population of 320,000 plants were classified by size using circular sieves with 5.5-mm, 6.0-mm, 6.5-mm, and 7.0-mm mesh sizes. For the evaluation of physiological quality, a 2x4 factorial design was applied, with two cultivars and four seed sizes. Germination, seedling emergence, accelerated aging, seedling dry matter, and emergence speed index were evaluated. Smaller seeds gave rise to shorter plants with a lower first pod insertion height. Larger seeds had higher physiological quality. The M 5947 IPRO cultivar showed better seed performance and quality.

Soybean nutraceutical canonic inter-relations and its reflections on breeding

In recent years, questionings on the behavior of genotypes in different environments are frequent, especially those seeking to disclose the commercial and nutritional value of soybean genotypes. Consequently, this study – which is linked to the IRC Soybean Breeding Program located in Campos Borges, Rio Grande do Sul, Brazil – sought to analyze the physiological and nutritional aspects of S5 Soybean Segregating Families. Research design consisted of complete randomized blocks containing 40 soybean genotypes arranged in four repetitions, corresponding to F5 generation genotypes tested in 2018/2019. This generation was obtained via artificial hybridizations of F1s plants carried out in 2014/2015, F2s in 2015/2016, F3 segregating families in 2016/2017 and F4 in 2017/2018. Traits were evaluated by a statistical model, verifying normality and homogeneity of variances. Behavioral explanation of the F5 Soybean Segregating Families was calculated using analysis of variance, grouping of means, and linear and canonical correlation. Analysis of variance showed a significant difference (p &lt;0.01) for all variables, indicating the existence of genetic variability. F5 Segregating Families IRC8_130 and IRC31_102 show promising results in breeding programs involving physiological and nutritional aspects. Crude protein, crude fiber, first pod insertion height, plant height and number of pods with 4 grains, are dominant and determining characteristics for establishing segregating generations, and can be used in breeding programs.

AGRONOMIC CHARACTERISTICS AND PRODUCTIVITY OF SOYBEAN SUBMITTED TO DOSES OF NITROGEN FERTILIZATION AND INOCULATION WITH PANTOEA AGGLOMERANS STRAIN O4

The soybean (Glycine max (L.) Merrill) is a prominent crop in the world grain scenario, it is currently cultivated in practically all the Brazilian national territory. Brazil appears as the world's second largest producer of this grain. Soybean cultivation is still the crop that consumes the most fertilizers in Brazil, with Nitrogen being the most required nutrient in the plant. The objective of this study was to evaluate the effect of seed inoculation with Pantoea Agglomerans Strain O4 bacteria and their relationship with nitrogen doses on soybean development and yield. The experiment was carried out in the experimental area of the Center of Agrarian Sciences and Biodiversity (CCAB), Federal University of Cariri (UFCA), in Crato - CE, in a randomized block design, in a subdivided plot, with three replications, thus totaling 24 experimental plots. The plots were four nitrogen doses (0, 25, 50 and 100% of the recommended dose) and the subplots referring to the use of AzotoBarvar inoculant (with and without). The variables analyzed were: plant height, first pod insertion height, number of branches per plant, number of pods per plant, pod per plant mass, mass of 100 grains, grain mass per plant and productivity. The data were submitted to analysis of variance by the F test and the means of the Bavar factor compared by the Tukey test at 5% of probability. The statistical program Sisvar 5.3 was used for the statistical analysis. According to the analysis of variance none of the variables presented significant results, for the interaction Fertilizer*Barvar or for the AzotoBarvar and Fertilizer factors separately. According to the means test, however, it was observed better results for plant height, number of pods per plant, pod mass per plant, grain mass per plant and productivity in the presence of the inoculant.

Genome-Wide Association Study Identifies Genomic Regions for Important Morpho-Agronomic Traits in Mesoamerican Common Bean.

The population growth trend in recent decades has resulted in continuing efforts to guarantee food security in which leguminous plants, such as the common bean (Phaseolus vulgaris L.), play a particularly important role as they are relatively cheap and have high nutritional value. To meet this demand for food, the main target for genetic improvement programs is to increase productivity, which is a complex quantitative trait influenced by many component traits. This research aims to identify Quantitative Trait Nucleotides (QTNs) associated with productivity and its components using multi-locus genome-wide association studies. Ten morpho-agronomic traits [plant height (PH), first pod insertion height (FPIH), number of nodules (NN), pod length (PL), total number of pods per plant (NPP), number of locules per pod (LP), number of seeds per pod (SP), total seed weight per plant (TSW), 100-seed weight (W100), and grain yield (YLD)] were evaluated in four environments for 178 Mesoamerican common bean domesticated accessions belonging to the Brazilian Diversity Panel. In order to identify stable QTNs, only those identified by multiple methods (mrMLM, FASTmrMLM, pLARmEB, and ISIS EM-BLASSO) or in multiple environments were selected. Among the identified QTNs, 64 were detected at least thrice by different methods or in different environments, and 39 showed significant phenotypic differences between their corresponding alleles. The alleles that positively increased the corresponding traits, except PH (for which lower values are desired), were considered favorable alleles. The most influenced trait by the accumulation of favorable alleles was PH, showing a 51.7% reduction, while NN, TSW, YLD, FPIH, and NPP increased between 18 and 34%. Identifying QTNs in several environments (four environments and overall adjusted mean) and by multiple methods reinforces the reliability of the associations obtained and the importance of conducting these studies in multiple environments. Using these QTNs through molecular techniques for genetic improvement, such as marker-assisted selection or genomic selection, can be a strategy to increase common bean production.

Vegetative and productive performance of two soybean cultivars at different plant densities

The spatial arrangement and plant population have been highlighted as fundamental tools for increasing productivity. The objective was to evaluate the vegetative and productive performance of two soybean cultivars at different plant densities. Seeds of soybean cultivars (TMG 7063 IPRO and BS 2606 IPRO), recommended for the Alto Paranaíba region in the state Minas Gerais, were used and sown at seven different densities (8, 10, 12, 14, 16, 18 and 20 plants meter-1, equivalent to 160, 200, 240, 280, 280, 320, 360 and 400 thousand plants hectare-1, where they were evaluated in the development stages R1 (plant height) and R8 (height of the insertion of the first pod, plant height, number of nodes, number of branches, productivity per plant and productivity per hectare). The experiment was set up according to a randomized block design, in the factorial scheme A x B, being factor A composed by the cultivars and factor B by plant densities with three repetitions (blocks). Increased plant population resulted in greater first pod insertion height and final plant height, fewer nodes and branches and the average yield per hectare increased linearly, with the TMG 7063 IPRO cultivar being more productive under these conditions (52.7 bags of 60 kg per hectare).

CONTRIBUTION OF THE ADDITIVE GENETIC EFFECTS IN SOYBEAN BREEDING AIMING AT THE AGRONOMIC IDEOTYPE

The development of new genotypes and their availability to the agricultural market is decisive for the success of the Brazilian soybean production chain. This study aimed to estimate the components of variance and genetic parameters of aspects of agronomic importance and to predict the selection of transgressive soybean populations and families based on the agronomic ideotype. The segregating families were conducted in an enlarged block design, composed of 285 F3 segregating families corresponding to the unusual treatments, and together with seven commercial cultivars assigned as common treatments, arranged in four replications. The characters of agronomic interest were measured the first pod insertion height, plant height, number of pods on the main stem, number of pods on the branches, pods containing only one seed, pods containing two seeds, pods containing three seeds, pods containing four seeds and seed mass. Were estimated additive genetic variance, genetic variance of the F3 segregating families, genetic variance of F2 segregating population, residual variance, phenotypic variance, narrow sense heritability, coefficient of determination for the effects of the F3 segregating family, coefficient of determination for the effects of the progeny, genetic variation coefficient, residual variation coefficient and predicted genetic ranking for the best F2 segregating populations and F3 segregating families. The pronounced additive genetic gains in the progeny showed higher values for the characters measured: first pod insertion height with 1.84%, for the family and population, the additivity presented the highest values for the number of pods with four grains. The selection of the progenies through the agronomic ideotype based on the greatest genetic gains of the morphological characters weighted by the largest seed mass will thus lead these populations to joint selection for the other yield components.

Nitrogen fertilization on soybean crop over straw of forage sorghum intercropped with Urochloa ruziziensis

The experiment was carried out to evaluate the influence of N on the agronomic characteristics of soybean crop under no-tillage system over forage sorghum intercropped with Urochloa ruziziensis and on straw degradation. Four treatments (nitrogen doses) were used: 0; 20; 40 and 60 kg of N ha-1. N were applied at V3-V4 stage, using ammonium nitrate as the N source, containing 30% N. The experimental design was a randomized block design with four replications. The evaluation of dry matter quantity of forage sorghum and U. ruziziensis straw was carried out before the sowing of forage sorghum and U. ruziziensis and after soybean harvest. The soybean crop parameters evaluated were, as follows: first pod insertion height and plant height, final stand ha-1 and grain yield ha-1. Evaluations were performed at the soybean crop harvest. Nitrogen fertilization did not influence the straw decomposition of U. ruziziensis and forage sorghum nor the first pod insertion height, plant height and final stand ha-1 of soybean crop. Nevertheless, fertilization showed a quadratic behavior in the 2015/2016 crop in relation to grain yield, with a reduction in yield at doses greater than 21 kg of N ha-1, and a linear increase in the 2016/2017 crop. Key words: Ammonium nitrate, Glycine max L., no-tillage.

Relative maturity group and its relationships with the non preferential sowing season of soybean

The cultivation of soybeans is the main agricultural commodity in Brazil, the increase in the cultivated area in recent years and the productivity of grains is interconnected with numerous factors such as sowing time, water availability, temperature and photoperiod. The objective of this work was to evaluate the duration of phenological sub-periods and the productivity of soybean cultivars from different groups of relative maturation, sown in two seasons in the off-season in the northwest region of the State of Rio Grande do Sul (RS). The experiment was carried out at Agropecuária Bubans geographically located in the county of Ijuí in the state of RS, considered medium locality. The experiment was carried out using a randomized block design with four replications, the experimental units consisted of four lines, four meters long, 0.50 m apart. The treatments were eight soybean cultivars with different groups of relative maturity (4.8, 5.8, 5.9, 6.2, 6.3, 6.4, 6.7 and 7.8) sown on January 5 and 22, 2019 (from agricultural zoning, the preferred season for sowing in this region is from october to december), constituting an 8 x 2 factorial experiment (Cultivars x sowing times). Assessments of the duration of phenological sub-periods and of the yield components of the culture were carried out, being measured with total plant height, first pod insertion height, number of lateral branches, number of reproductive nodes on the main stem, total number of nodes on the main stem, number of pods with one, two, three and four grains, pods mass of one, two, three and four grains, total grain mass per plant, thousand seed mass and grain yield. The most productive relative maturity group is 6.3 being sown in the first non-preferential season for soybeans in Rio Grande do Sul. The second sowing time changed the dynamics of association of the measured variables, with changes in the cycle, reductions in the vegetative and reproductive period.

Agronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome

ABSTRACT Soybean is an alternative crop to be used in intensified land use systems and recovery of degraded areas in Brazil. Thus, the objective of this study was to evaluate the agronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome. Soybean crop was grown in alleys with widths of 18, 30, and 42 m between the 4-row tree sets of eucalyptus and evaluated in two agricultural years (2016-2017 and 2017-2018). Plant height, first pod insertion height, number of grains per pod, number of pods per plant, 100-grain weight, and grain yield of soybean plants at maturation stage were evaluated in different distances from the eucalyptus (10, 20, 30 and 45% of the alley width). The lowest mean grain yield was found for the alley of 18 m in the 2017-2018 agricultural year. The proximity of soybean plants to eucalyptus trees affects negatively the grain yield, plant height, first pod insertion height, plant population, and number of pods per plant. The crop-livestock-forest integration system, with the forest component consisting of 5-year-old eucalyptus trees (technical age for harvest), resulted in higher soybean grain yields for the alley of 42 m. The growth of soybean crops in alleys of 18 m between 4-row tree sets of 5-year-old eucalyptus trees is not recommended for the Southwestern region of the Brazilian Amazon biome.

New insights on molybdenum fertilization in common bean under no-tillage system: rates and application time to obtain high vigor seeds

Molybdenum (Mo) is a key element in the N fixing and assimilation processes in leguminous plants. This study aimed to evaluate the effects of Mo fertilization on the yield and seed vigor of the common bean. Molybdenum was applied at six rates (0, 20, 40, 80, 120 and 160 g ha−1) in field trials over 2 consecutive years (2015 and 2016). Foliar applications were performed during the phenological stages V4 (4th trifoliolate leaf unfolded) and R1 (early flowering). The SPAD index, height of first pod insertion, number of pods per plant, number of seeds per pod, weight of 100 seeds, yield and seed vigor were determined. Molybdenum affected the production of reproductive organs only in the second agricultural year. Application of Mo at T-V4 resulted in an increase in the number of pods per plant (11%), and at 120 g ha−1, there was an increase (41%) in the number of seeds per pod, but this did not result in a yield seed increase. Molybdenum applied at the T-V4 phase reduced electrical conductivity in the first year of the experiment at rates of 40 g ha−1 (17%) and 160 g ha−1 (13%). In the second agricultural year, Mo applied at the T-R1 phase reduced in 44% the electrical conductivity, as well as the application of 20 g ha−1 also at the T-R1 phase increased seed germination (28%), seedling length (8%), and length of the primary root (10%). Different responses to the Mo application time and dose between the experimental years suggest that common bean plants recycle Mo. Molybdenum applied in the first agricultural year may have satisfied the initial Mo demand of the common beans in the second year of crop due it's low Mo requirement. This study show that foliar Mo application is an important strategy to achieve sustainable production of higher quality seeds of common bean.

Genotypic Selection for Soybean Earliness

Obtaining early-maturing soybean cultivars with high yield performance has long been the focus of breeding programs. Obtaining the estimates of genetic and phenotypic parameters can assist breeders at selecting the superior genotypes. Therefore, the aim was to estimate the genetic and phenotypic parameters of progenies throughout the recurrent selection for early maturity in soybeans and to select progenies with superior agronomic traits. S0:1 progenies were evaluated in one site during the 2015/2016 harvest using a 12 &amp;times; 12 lattice design, with one 2-meter row plot with two replicates. The S0:2 progenies were evaluated during the 2016/2017 harvest using an 8 &amp;times; 8 lattice design, with one 3-meter row plot with three replicates. The S0:3 progenies were evaluated during the 2017/2018 harvest using a 5 &amp;times; 5 lattice design, with two 3-meter rows plots with three replicates. Both S0:2 and S0:3 progenies were evaluated in three different sites. The days to flowering, full maturity, first pod insertion height, plant height, lodging index and grain yield traits was evaluated. The data were analyzed using a mixed model approach. The genetic and phenotypic parameters, expected gain with selection, realized heritability, correlated response and the frequency distributions of the adjusted means were estimated. The estimates of the variance components have evidenced variability among the progenies, enabling the selection of superior genotypes. All the evaluated progenies showed good agronomic performance, combining early maturity and productive performance. When early-maturing progenies were selected, there was a reduction in days to flowering, plant height, first pod insertion height, lodging and yield.