Pod Insertion Height Research Articles

Classifying Soybean Cultivars Using an Univariate and Multivariate Approach

Selection indices are good for classification because they consider several evaluated traits simultaneously to identify superior cultivars with a combination of the traits of interest. Adaptability/stability methods enable determining contributions to the genotype-by-environment (G × E) interaction and the risk associated with each cultivar. This study used a univariate and multivariate strategy to identify commercial soybean cultivars that presented both precocity and good productive performance and studied the G × E interaction considering all cultivars both simultaneously and by maturation groups. The experiments were conducted in the agricultural years 2014/15 and 2015/16 in seven distinct environments in southern Minas Gerais State, Brazil, considering a combination of locations and seasons. A randomized complete block design was used, and the treatments included 35 commercial soybean cultivars. In the univariate analysis, were evaluate several traits. Selection indices were calculated considering yield, harvest index, plant height, first pod insertion height and absolute maturation. The selection strategy efficiencies were quantified using the coincidence index. Each cultivar’s contribution to the G × E interaction and associated risk were determined using the ecovalence and confidence index methods, respectively. The results showed that the NS 7000 IPRO and NS 7209 IPRO cultivars were the most productive. The NS 7000 IPRO cultivar, although obtaining a good yield, contributed greatly to the G × E interaction when considering the maturation groups. The low coincidence in ranking the strategies indicates that more than one agronomic trait should be used to classify the superior cultivars.

Seed vigor level in association to fertilizer distribution

This work aimed at evaluating yielding responses of soybean seeds production fields in response to the association between seed vigor level and fertilizer distribution systems at the sowing line.Experimental design was randomized blocks design, with two growing environments (Passo Fundo - RS and Ernestina - RS) x three vigor levels (high = 90%, medium = 70% and low = 60%) x three fertilizer distribution systems (absence, conventional and by transhipment), arranged in four replicates, grain yield (GY). For grain yield (GY), it was applied the method genotype main effects and genotype environment interaction (GGE). Seed vigor levels and fertilizer distribution systems influence on seed yield, first pod insertion height, plant height, number of pods in the main stem and ramifications, magnitude and length of ramifications in soybean.The high vigor level in the conventional and by transshipment fertilization systems provided an absolute increase of 10.9 and 5.6% in seed yield, respectively, in Ernestina-RS. The conventional fertilizer distribution system, in Passo Fundo-RS, increased seed yield in 12.5% in plants originated from low vigor seeds.

Agronomic optimal plant density for semiupright cowpea as a second crop in southeastern Brazil

AbstractCowpea [Vigna unguiculata (L.) Walp.] cultivars with high yield potential and suitable plant architecture for mechanized harvesting have recently shown a growing interest to be cultivated as a second crop in fall–winter season of southeastern Brazil. The agronomic optimal plant density (AOPD) is one of the main management factors defining attainable yield. However, in the scientific literature for semiupright cowpea cultivars grown in fall–winter season in southeastern Brazil the AOPD is not yet clearly defined. A 3‐yr study was conducted to evaluate the effect of five plant densities (100,000–500,000 plants ha−1) on growth, seed yield and its components for two cowpea cultivars (BRS Guariba and BRS Novaera) in Botucatu, southeastern Brazil. The AOPD for cowpea increased as the attainable yield improved. The increase in plant density promoted increases in leaf area index (LAI) and the position (measured in height) of the first pod insertion for cowpea plants, but negatively affected per‐plant scale surviving rate, leaf area, aboveground dry matter (DM), and yield resulting from intraspecific competition. Maximum cowpea seed yields were achieved with AOPD ranging from 216,630 to 290,537 plants ha−1 (8–24% greater than under the lowest plant density). On average, 259,000 plants ha−1 was estimated for the AOPD to achieve maximum seed yield of semiupright cowpea grown as a second crop in fall–winter season in southeastern Brazil.

Desempenho agronômico de genótipos de feijão comum cultivados no ecótono Cerrado-Pantanal

Objetivo deste estudo foi o de avaliar o desempenho agronômico de 17 genótipos de feijão comum dos grupos comerciais carioca e preto, entre linhagens avançadas e variedades comerciais, na região do ecótono Cerrado-Pantanal. O estudo foi desenvolvido na área experimental da Universidade Estadual de Mato Grosso do Sul, Unidade Universitária de Aquidauana, na safra da “seca”. O delineamento experimental utilizado foi o de blocos casualizados, com 17 tratamentos e três repetições. Os genótipos foram avaliados quanto aos caracteres: dias para o florescimento; altura de inserção da primeira vagem; altura de planta; número de vagens por planta; número de grãos por vagem; massa de 100 grãos; produtividade de grãos e suscetibilidade às doenças. Os dados obtidos, exceto para as doenças, foram submetidos à análise de variância e as médias agrupadas pelo teste de Scott-Knott a 5% de probabilidade. Os genótipos diferiram entre si para as variáveis, dias para florescimento, altura de inserção de vagem, massa de cem grãos e produtividade. Nas condições da região, apenas os genótipos IAC Alvorada, IAPAR 81, TAA Bola Cheia, IAC Diplomata, BRS Esteio, Pérola, BRS Estilo, CNFC 10729 e CNFP 10 794, apresentaram desempenho agronômico superior em comparação aos demais. Todos os genótipos se mostraram suscetíveis ao crestamento bacteriano e à mancha angular.

Interaction of chemical attributes of an Red Oxisol in the brazilian Savannah cultivated with soy under two management systems

Soil compaction and nutrient accumulation on the surface have been a major problem. Soil scarification can alter nutrient variability due to partial soil mobilization. This research aimed to evaluate by multivariate techniques the main chemical attributes of the soil that best relate to soybean yield and production components. The experiment was performed in a dystrophic Red Oxisol, in the agricultural year of 2015/16, in Savannah area located in the Selvíria County, MS, Brazil. The experiment consisted of two cultivated areas, one under no-tillage system (NTS) implemented 13 years ago and another in minimum cultivation system scarified (MCSS). Were evaluated: population of plants, first pod insertion height, plant height, the number of pods per plant, grain per plant, grain per pod, the weight of 100 grains, grain yield and soil chemical attributes. Soybean yield was higher in NTS when compared to MCSS scarified. The values of pH, calcium content, magnesium and phosphorus in the layer of 0-0.10 m, as well as the content of K in 0.10-0.20 m, are the attributes that most contributed to the increase of soybean productivity in NTS and MCSS.

Seleção de cultivares de soja na região do ecótono cerrado-pantanal

O objetivo deste trabalho foi avaliar o desempenho de dezesseis cultivares de soja e indicar aqueles com melhor adaptação para o cultivo na região de Aquidauana, MS. O trabalho foi realizado na área experimental da Universidade Estadual de Mato Grosso do Sul, Unidade de Aquidauana, no ano agrícola 2014/2015, em sistema plantio convencional. O delineamento experimental utilizado foi o inteiramente casualizado, com 16 tratamentos (RR: 97R21, 97R71, 97R73, 97Y07, AS3610, AS3730, AS3797, B4184, B4377, CD238, MOSOY6410, P98Y11, POTÊNCIA, SYN1163, SYN13671 e SYN9070) e 4 repetições. As parcelas consistiram de sete linhas com 5 m de comprimento, com espaçamento de 0,45 m entre linhas e densidade de 15 plantas por metro. Foram avaliados os caracteres agronômicos altura de planta na maturação, altura de inserção de primeira vagem, número de ramificações, número de vagens por planta, número de grãos por vagens, massa de cem grãos e produtividade de grãos. Após a coleta dos dados foi verificado o ajuste dos erros pelo teste de Liliefors e a homogeneidade das variâncias pelo teste de Bartlett, e os dados foram submetidos a analise de variância e ao agrupamento de médias pelo teste de Skott-Knott á 5% de probabilidade. Conclui-se que a cultivar B4377 obteve o melhor desempenho analisando as variáveis AP, AIV, NR e NVP em conjunto. As cultivares que obtiveram melhor desempenho analisando as variáveis NGV, MCG e PROD em conjunto foram AS3730 e P98Y11. Altura de planta NVP e MCG não influenciaram na melhor produtividade de grãos. Considerando a produtividade de grãos, todos os materiais avaliados podem ser recomendados para a região.

Agronomic performance of soybean genotypes in Brazil sub-subtropical climate

Soybean is the main economic crop of Brazilian agribusiness, and the extreme south of the country is considered a new agricultural frontier. The objective of this study was to evaluate the components of the yield and agronomic performance of soybean genotypes in the south of Rio Grande do Sul as well as to verify the linear relationships of the measured characters. The study was carried out in the municipality of Pelotas, Rio Grande do Sul, Brazil, in the crop harvest 2016. The experimental design was a randomized complete block design, containing 25 soybean genotypes arranged in four replicates. The experimental units were composed of five sowing lines, spaced by 0.45 meters and three meters in length. The measured characters were: first pod insertion height, plant height, number of branches, length of branches, number of pods in the main stem, number of pods in the branches, number of pods with one, two, three and four seeds, contributing to the pod mass with one, two, three and four seeds. The data were submitted to analysis of variance at 5% of probability, where for the significant characters the averages were compared by the Duncan’s test and Pearson's linear correlation was performed in order to identify the tendency of association among the measured characters. The genotypes DM 6159IPRO, BS2606 IPRO, BMX Magna, BMX Potência, TMG7062 IPRO, LG 60163 IPRO revealed superior characters, which can positively influence grain yield. There is a correlation among the morphological characters of the soybean cultivated in southern Brazil between the number of pods in the main stem and the number of pods in the branches, as well as between the number of pods with two seeds and the number of pods in the branches.

Inoculante e bioestimulante no desempenho do feijão comum cultivado no ecótono Cerrado-Pantanal

O objetivo do estudo foi avaliar o efeito de doses de inoculante e suas interações com bioestimulante no feijão comum. O experimento foi realizado na área experimental da Universidade Estadual de Mato Grosso do Sul, em Aquidauana-MS, utilizando a cultivar TAA Dama do grupo comercial Carioca. O delineamento experimental foi em blocos casualizados, em esquema fatorial 2x5, com quatro repetições. O primeiro fator constitui-se da presença ou ausência de bioestimulante. O segundo fator as doses de inoculante (0 mL, 150 mL, 300 mL, 600 mL, 1200 mL a cada 50 kg de sementes). Foram avaliados o número de nódulos por planta, atividade nodular, matéria verde e seca de nódulos, matéria verde e seca da parte aérea e da raiz, comprimento e densidade da raiz, teor de nitrogênio e fósforo foliar, altura de inserção de primeira vagem, altura de plantas, número de ramificações, número de grãos por vagem, massa de cem grãos e produtividade de grãos. A aplicação do bioestimulante isolado ou em associação com Rhizobium tropici no feijão comum não promove aumento de produtividade de grãos na cultura, ao contrário da prática da inoculação com o referido rizóbio. A dose recomendada do inoculante a base de R. tropici proporciona incrementos na produtividade do feijão comum. O aumento da dose é apenas desperdício.

CO-INOCULATION WITH Azospirillum brasilense AND Bradyrhizobium japonicum IN SOYBEAN IN THE FIRST AND THIRD YEAR OF CULTIVATION

<p><strong>Background. </strong>The use of microorganisms in agriculture, such as <em>Bradyrhizobium japonicum</em> and <em>Azospirillum brasilense</em> and soybean cultivation together with nitrogen fertilization, may be interesting alternatives to increase crop yield. The soybean with the use of <em>Azospirillum brasilense</em>, together with <em>Bradyrhizobium</em> bacteria, in a current approach aimed at agricultural, economic, social and environmental sustainability. <strong>Objective</strong>. To evaluate the influence of the application of different doses of <em>Azospirillum</em> <em>brasilense</em> on co-inoculation with <em>Bradyrhizobium japonicum</em> in the soybean crop, in the first and third year of cultivation. <strong>Methodology.</strong> The experiment was carried out in the municipality of Alta Floresta - MT, Brazil, in the harvest of 2016/2017. The treatments consisted of the combination of four doses (0, 2, 4, 8 mL kg<sup>-1</sup> of seeds) of the commercial product Nitrogeo AZ<sup>®</sup>, composed of <em>Azospirillum brasilense</em>, with 4 replicates. For the standard inoculant the commercial product Nitrogeo Soja Turfa<sup>®</sup> was used <em>Bradyrhizobium japonicum</em>, with a dose of 3.2 g kg<sup>-1</sup> of seeds. Height of first pod insertion, plant height, number of pods per plant, mass of one thousand grains, productivity and leaf content of nitrogen were analyzed. <strong>Results.</strong> There was an increasing in both grain yield and thousand grains weight in the treatments with <em>Azospirillum brasilense</em>. Higher plants with a higher number of pods were found in the area of the 3rd year of cultivation, compared to the area of the 1st year, however, the co-inoculant doses did not influence this variable. The highest grain yield was obtained with the use of 338 mL of commercial product per 50 kg of seeds. <strong>Conclusion. </strong>The use of these bacteria (<em>Azospirillum</em> with <em>Bradyrhizobium</em>) together contributes to increase productivity in the soybean crop.</p>

REML/BLUP applied to characterize important agronomic traits in segregating generations of bean (Phaseolus vulgaris L.)

The objective of this work was to estimate and predict the genetic gains through the REML/BLUP methodology for the characters of agronomic interest of common black beanas at segregating generations. The experiments were conducted in 2015, 2016 and 2017 in experimental design consisted of augmented blocks in four replicates. Superior genetic variability was identified for the first pod insertion height and plant height in the F4 segregating generation. For the number of pods, seeds and seed mass per plant, genetic contribution superior to the phenotype is expressed in F3 segregating generation. The prediction of genetic value defines that the number of pods, seeds and seed mass per plant can be potentiated in F2 segregating generation by selection of population 26, selection of F3families 64 and 49, F4 families 33 and 19. Through the estimations and genetic predictions of the characters measured in the segregating generations F2, F3 and F4 it is possible to define six multivariate genetic profiles. These strategies can be used in quantitative genetic studies aimed at increasing the production of common black bean seeds.

Planting Density and Soybean (Glycine max L.) Cultivars Effects on Yield Components in the Amazon

The aim of this study was to evaluate the influence of planting density and cultivar of soybean on yield components in the southeast Amazon. The experiment was carried out in an Oxisol, with a randomized block design in a 2 x 4 factorial scheme. The treatments were two soybean cultivars (BRS 9090 RR and BRS 8990 RR) and four planting densities (13, 15, 18 and 20 plants m-1), with three replications. First pod insertion height (IFP), plant height (H), number of pods per plant (NPP), grain yield (Y) and weight of 100 grains (W100) were evaluated. The insertion height of the first pod showed a tendency of increase with the increment of plants per linear meter for cultivar BRS 8990 RR, different of the behavior observed for the cultivar BRS 9090 RR, which only showed difference when the density of 300.000 plants ha-1 was tested. For plant height, among soybean cultivars, there was only difference in D400, with BRS 8990 RR showing a maximum height of 83.3 cm, 21% higher than BRS 9090 RR. When evaluated under D350, BRS 8990 RR showed an increase of 13% in the number of pods compared to BRS 9090 RR. Both cultivars showed linear behavior for the grain yield, increasing according the plant population, with the highest grain yield obtained under the density of 400.000 plants ha-1 (4527.3 kg ha-1). The weight of 100 grains was not influenced by any variation factor.

Expected values and predictive model for black seed (Plaseolus vulgaris L.) production

The objective of this work was to determine the tendencies of expected values, linear associations, and to define which traits compose the best predictive model for mass of seeds per plant of black and pinto bean genotypes from different regions of Rio Grande do Sul. The experiments were conducted in the agricultural years of (2015-2017). The expected values are increased as function of the segregating generation of F2, F3, F4 for first pod insertion height and plant height. Furthermore, black commercial group determines superiority for number of seeds per plant, while pinto genotypes are closely related to increments of mass of seeds per plant. Linear associations are specific to germplasm origin, commercial group and segregating generations of bean genotypes regarding traits of agronomic interest. The predictive model created to increase mass of seeds per plant is specific for germplasm origins and commercial group of beans. Seed yield of pinto genotypes is maximized by plant height and number of seeds per plant. For genotypes of black commercial group, this increase is achieved through plant height, number of pods and seeds per plant in F3 and F4 segregating generations.

Additive genetic prediction for F3 families of common black beans (Phaseolus vulgaris L.) using linear mixed models

The aim of study is to estimate the variance components and genetic parameters (REML), as well as to predict the genetic value (BLUP) of F3 families of common black beans for the components of seed production. The experimental design was augmented blocks, where the 83 F3 families were arranged only in each block, and the commercial controls were organized in three replicates. The additive genetic effects were determinant for plant height and first pod insertion height. The pronounced effects of the environment are expressed for the number of pods, seeds and seed mass per plant. Potentiality in the selection of higher F3 families are revealed through the 2CBRS population for plant height and first pod insertion height, for the components of seed yield the selections should be directed to the populations 2CARS and 1FVRS. The number of seeds and seed mass per plant were potentiated in more than 28% of the selected F3 families, and pronounceable genetic gains are obtained by the selection of families 66, 65 and 67. The inferences obtained in this study present theoretical and practical foundation, and can be applied in future studies of breeding and production of common black bean seeds.

Foliar applications of phosphorus, calcium, boron and potassium and their impacts on the seed yield and physiological and nutritional qualities of soybean

Using seeds of high physiological quality is important the establishment of a crop. Practices for quality seed production include sowing in the offseason and applying foliar macro and micronutrients to supplement fertilizers applied to the soil. The aim of this research was to evaluate the soybean yield and the physiological quality and nutritional content of seeds. Foliar fertilizer (24% P, 8% Ca, 4% K and 2.5% B) was applied at 0.50, 1.0, 1.5, 2.0 and 2.5 kg ha-1 at the R3 soybean stage in a completely randomized design with six replications. The experiment was carried out at two sites. The following traits were evaluated at the R6 stage: the final stand, plant height, height of the first pod insertion, number of branches and number of pods per plant. After the soybeans were harvested, the thousand grain mass and yield were evaluated. The contents of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, zinc, iron, copper and boron were evaluated. Furthermore, the germination, first germination count, accelerated aging, modified cold, electric conductivity and emergency speed index were measured. The data were analyzed by means of joint analysis. When the foliar fertilizer rates were significant, the polynomial regression models were adjusted. The number of pods per plant and yield increased at site 1 (Rancho Alegre d 'Oeste). Application of the foliar fertilizer only influenced the emergency speed index at site 2 (Mariluz) with regard to the physiological quality of the seeds. The P content was positively affected at both sites; the K, S, Zn and B contents were only positively affected at site 2.

Comparison of non-parametric indexes to select soybean genotypes obtained by recurrent selection

In the final steps of a breeding program, it is necessary to evaluate several traits, which makes it difficult to select the superior genotypes. This study aimed to compare nonlinear indexes in the selection of superior soybean inbred lines obtained by recurrent selection. The experiment was carried out in Londrina, Paraná State, Brazil. During the 2010/11 and 2011/12 seasons, 67 soybean inbred lines and two commercial controls (BMX Potência RR and NK 7059 RR) were evaluated. The experimental design was a randomized complete block with three replicates. The evaluated traits were: days to maturity, agronomic value, lodging, first pod insertion height, and grain yield. A combined analysis of variance for seasons was performed and the sum of ranks index, ideotype distance index, and cultivars selection index were applied. All traits were significant for the genotypic source of variation and showed complex genotype × environment interactions. The selection indexes were consistent with each other. The ideotype and cultivar selection index showed higher concordance on indication of 15 superior inbred lines with a coefficient of coincidence of 80%. The inbred lines SR-03, SR-12, SR-22, SR-41, SR-49, SR-55, SR-61, and SR-62 were indicated for all indexes and are therefore considered superior to other inbred lines.

Doses and potassium partitioning methods in soybean production components in an Amazonian savanna

After nitrogen, potassium is the macronutrient most required by soybean. To meet soy bean growth
 demands, it is necessary to use high K doses, which can lead to losses via leaching. The objective of the
 current study was to evaluate the effect of doses and methods of K fertilization on the components of soybean
 production, in the Yellow Latosol of an Amazonian savanna. The experiment was conducted using randomized
 complete block design with four replicates. Plots consisted of two fertilization methods (M1 – fertilization on
 planting and at 35 days after emergence - DAE and M2 – on planting, then divided between 20 and 35 DAE).
 Subplots where five doses of potassium (K2O at 0, 40, 80, 120 and 160 kg ha-1) were randomized. Measured
 variables were: plant stand (PS), plant height (PH), height of first pod insertion (FP), number of pods per
 plant (PP), bean mass per plant (BM), and bean yield (BY). Because of the low exchangeable K content and
 medium texture of the study soil, deployed methodology consisting of plant fertilization and two applications
 to facilitate high soybean yields. Agronomic efficiency proved to be a good indicator for assaying the best K2O
 dose, as it is sensitive to initial soil exchangeable K levels. The dose giving maximum agronomic efficiency
 was 88.5 kg ha-1 of K2O, converting each kg of K2O in 14.3 kg of soybeans.

Implicações da análise univariada e multivariada na dissimilaridade de acessos de feijão comum

Univariate and multivariate analyses have been routinely used to discriminate genotypes in breeding programs, but their relationship is not always considered. The objective of this study was to relate univariate and multivariate analyses on the dissimilarity among common bean accessions based on characteristics such as days until emergence, plant height, first pod insertion height, harvest days, final stand, number of pods per plant, pod length, 100-grain weight, grain yield and seed length, width and thickness. Data were submitted to univariate analysis of variance, with a comparison of means by the Scott-Knott test, and multivariate analysis to estimate the genetic divergence based on the generalized Mahalanobis distance, grouping the accesses through Tocher’s method. The relative importance of the characters was also estimated by Singh's method, performing the multicollinearity diagnosis. There was a significant difference for all the evaluated characteristics, showing the existence of variability between the accesses. The greater variability found was related to seed characteristics. It was possible to relate univariate and multivariate analyses, since there was a relationship between the groups generated by Scott-Knott’s test and the percentage of the relative contribution of the evaluated characters. However, the clustering obtained in the univariate analysis for the characteristic that contributed the most to the divergence between the accessions was not compatible with the cluster generated by Tocher’s method. The coupled use of these analyses can help breeders to decide, choosing superior genotypes and that present wide genetic divergence, mainly for the characteristics of greater interest.

Agronomic performance of soybean genotypes submitted to different population densities in the city of Uberlândia - MG

Sowing density is widely studied in the soybean crop in order to define the best plant population for each cultivar available on the market. The objective of this work was to evaluate the agronomic traits of three soybean geno­types (UFUS LVR, UFUS 7910, and UFUS 8301) in four population densities (12; 14; 16; 18 pl m -1 ), in Uberlândia-MG. The design was a randomized complete block with four replicates, with sowing performed on February 12, 2016. The following were evaluated: plant height at flowering (PHF) and maturity (PHM); number of branched nodes (NBN); lateral branch inclination (LBI); first pod insertion height (FPIH); number of pods per plant (NPP); number of seeds per pod (NSP); hundred-grain weight (HGW); and grain yield (kg ha -1 ). There were sig­nificant interactions between genotypes and densities for all characters, except for LBI and NSP. When increasing the sowing density from 14 to 18 pl m -1 , cultivar UFUS 7910 showed a reduction in plant height at maturity, and strain UFUS LRV had the first pod insertion height increased. The hundred-grain weight was not altered for culti­vars UFUS LRV and UFUS 7910 when increasing the density from 12 to 18 pl m -1 . For the three genotypes, there was a reduction in grain yield when sown in a higher sowing density (density of 18 pl m -1 ). The densities of 16 pl m -1 and 12 pl m -1 provided better grain yields for genotypes UFUS LVR and UFU 7910, respectively. The densi­ties of 12 pl m -1 and 14 pl m -1 allowed a greater number of pods and higher yield for cultivar UFUS 8301.

Effects on food-type soybean cultivars when biofortified with different rates of zinc

The objective of this research was to verify the effect of biofortifying food-type soybean grains with different foliar applied zinc rates. The experiment was completely randomized with four replicates, in a 5 × 5 factorial scheme, which consisted of five soybean varieties: BRS 010 (black tegument), BRS 213 (yellow), BRSMG 790A (yellow), BRSMG 800A (brown), and Favorita RR® (yellow) combined with five zinc foliar rates applied at the reproductive 4 (R4) stage (0, 0.91, 1.82, 2.73, and 6.37 mg L-1). The analyzed parameters were plant height, first pod insertion height, number of pods per plant, number of grains per plant, pod weight per plant, grains mass per plant, 100-grain dry matter, mineral composition of the grains, lipid and protein content. Foliar fertilization with zinc increased plant height, grain mass, and protein content in soybean grains. It also significantly increased zinc content in the grain and this increase was independent of the studied variety, but was a function of the zinc rate applied.

Nitrogen fertilization in super-early cycle common bean using new sources of urea

The efficiency of new fertilizers as a nitrogen source in super-early cycle common bean cultivars still needs to be better known. The objective was to quantify the effect of new sources and time of application of nitrogen on yield and yield components of a super-early cycle bean cultivar. The experiment was conducted in the city of Rio Verde, state of Goias, Brazil, using the experimental design of randomized blocks, in a 3x3+1 factorial scheme, with four replications. The first factor was constituted by nitrogen (N) sources: traditional urea, zeolite-associated urea, and urea with urease inhibitor, using the dose of 80 kg ha -1 N. The second factor was application stages: V2, V3, and V4, that is, when 50% of the plants had the first pair of unifoliolate leaves, the first trifoliolate leaf, and the third trifoliolate leaf fully expanded, respectively. Moreover, an additional treatment was used, without N application (control). The cultivar used was BRS FC104, of super-early cycle, from 60 to 65 days. The following were measured: relative chlorophyll index (RCI), plant height, first pod insertion height, number of pods per plant, number of grains per pod, mass of 100 grains and yield. There was no significant difference between sources and application stages regarding the number of pods per plant, number of grains per pod, plant height and first pod insertion height. The highest yields were obtained with the use of zeolite-associated urea, and the best application stage was V4. The use of urea with urease inhibitor did not provide an increase in grain yield compared to the control treatment.