ABSTRACT Managing electrical conductivity levels is one of the fundamentals required to obtain greater production and better quality of vegetables. The aim of this study was to evaluate the effect of electrical conductivity of the nutrient solution on the kohlrabi crop cultivated in semi-hydroponic system. A randomized block design was used with five treatments associated with the electrical conductivity of the nutrient solution (1.31, 1.71, 2.37, 2.98, and 3.75 dS m-1) and four replications. The plants were harvested 78 days after transplanting and evaluated for growth, production, and postharvest quality. Nutrient solution with electrical conductivity (EC) of 1.31 dS m-1 promotes greater production of purple kohlrabi. The increase in EC reduced linearly most of the analyzed variables (leaf area, fresh mass of leaves, bulb and shoot, dry mass of leaves and total, bulb volume and firmness), with more significant losses for the bulb fresh mass (50.54%) and bulb volume (57.37%) variables. The use of nutrient solution with EC between 2.3 and 2.9 dS m-1 increased the vitamin C content and the titratable acidity.

RESUMO O manejo dos níveis de condutividade elétrica é um dos fundamentos necessários para se obter maior produção e melhor qualidade de hortaliças. O objetivo deste trabalho foi avaliar o efeito da condutividade elétrica da solução nutritiva na cultura da couve-rábano cultivada em sistema semi-hidropônico. O delineamento experimental foi em blocos casualizados com cinco tratamentos associados à condutividade elétrica da solução nutritiva (1,31; 1,71; 2,37; 2,98 e 3,75 dS m-1) e quatro repetições. As plantas foram colhidas 78 dias após o transplante e avaliadas quanto ao crescimento, produção e qualidade pós-colheita. Solução nutritiva com condutividade elétrica (CE) de 1,31 dS m-1 proporciona maior produção de couve-rábano roxa. O aumento da CE reduziu linearmente a maioria das variáveis analisadas (área foliar, massa fresca de folhas, bulbos e parte aérea, massa seca de folhas e totais, volume e firmeza de bulbos), com perdas mais expressivas para as variáveis massa fresca de bulbos (50,54%) e volume de bulbos (57,37%). A utilização de solução nutritiva com CE entre 2,3 e 2,9 dS m-1 aumentou o teor de vitamina C e a acidez titulável.

Abstract: A methodology for multispectral camera calibration using convolutional neural networks is presented. RGB images were captured from the multispectral camera for each of the standards, the samples are taken under the same lighting conditions and with the same capture angle. The images are fragmented into small matrix sizes added to a specific class, and saved with a special label to distinguish it from the entire class database, the same process takes the remaining 7 Lucideon Std color tiles. One of the tiles will correspond to a particular class with an equal dimension for all classes. Finally, based on the presented methodology, it is possible to calibrate the camera with respect to the references.

Resumen: Se presenta una metodología para la calibración de cámara multiespectral mediante redes neuronales convolucionales. Se capturaron imágenes en RGB de la cámara multiespectral para cada uno de los estándares, las muestras son tomadas con las mismas condiciones de iluminación y con el mismo ángulo de captura. Las imágenes son fragmentadas en pequeños tamaños de matrices agregados a una clase específica, y guardada con una etiqueta especial para distinguirla de toda la base de datos de la clase, el mismo proceso lleva los 7 cerámicos de color restantes Lucideon Std. Uno de los cerámicos corresponderá a una clase en particular con una dimensión igual para todas las clases. Finalmente, con base a la metodología presentada se logra calibrar la cámara con respecto a las referencias.

Infections in fruits caused by fungi reduce the quantity and quality of food for human consumption, in addition to causing economic losses. In this sense, this study aimed to address the effects of eugenol nanocapsules (NCs) based on chitosan and carboxymethylcellulose in protecting nectarines against Monilinia fructicola, a brown rot agent, a worldwide important disease. NCs were prepared by layer-by-layer (LbL) self-assembly starting from an anionic template and deposition with up to two polymeric layers. The hydrodynamic diameters ranged from 158 nm (nanoemulsion), 360 nm (one polymeric layer) to 398 nm (two polymeric layers). NCs presented, during the in vitro release, the release of eugenol following a first order process. In addition to being in the region of stability (zeta potential ca. |30| mV), the capsules showed good adhesion to the nectarine surface. In relation to brown rot, the eugenol NCs with chitosan proved to be the best formulation compared to nanoemulsion and NCs with two polymeric layers for its control, increasing the probability that the fruits remain without symptoms, even after 7 days. Therefore, this study demonstrated that chitosan NCs containing eugenol could be an alternative to preserve fruit for longer periods in post-harvest.

ABSTRACT The aim of this work was to determine the sex ratio of the offspring born from ovulations of the left or right ovaries in naturally mated llamas. Females (n=188) with the presence of an ovarian follicle ≥7 mm received controlled natural mating (Day 0). Ovulation was confirmed on day 2 by the disappearance of the ovarian follicle (n=146). Then, 104 (71.2%) females diagnosed pregnant by ultrasonography were obtained 40-45 days after mating. The mating and calving date, sex and body weight of the calf at birth were recorded in 92 individuals. The overall sex ratio of the offspring and the sex ratio of the offspring from each ovary were compared using the Chi-square goodness-of-fit test, with the expected ratio being 1:1. Ovulations from both ovaries produced a similar (p=0.14) proportion of calves born and the male: female ratio was similar. However, more male offspring originated from the left ovary than from the right (65.2 vs. 34.8%, respectively; p=0.04), although the percentages of males born originated from ovulations from the left ovary (30/53=56.6%; p=0.33) and right ovary (16/39=41.0%; p=0.26) were not different from the expected ratio (1:1). The length of gestation and live weight at birth were statistically similar between sexes.

RESUMEN El objetivo del presente trabajo fue determinar la relación de sexos de las crías nacidas provenientes de ovulaciones de los ovarios izquierdo o derecho en llamas naturalmente apareadas. Hembras (n=188) con presencia de un folículo ovárico ≥ 7 mm recibieron monta natural controlada (Día 0). Se confirmó la ovulación en el día 2 por la desaparición del folículo ovárico (n=146). Se obtuvieron 104 (71.2%) hembras diagnosticadas preñadas por medio de ultrasonografía a los 40-45 días de la monta. Se registró la fecha de monta y parición, sexo y peso vivo de la cría al nacimiento en 92 llamas. La relación sexo de la cría y la relación de sexo de las crías provenientes de cada ovario fueron comparadas mediante la prueba de Chi cuadrado de bondad de ajuste, siendo la relación esperada de 1:1. Ovulaciones provenientes de ambos ovarios produjeron similar (p=0.14) proporción de crías nacidas y la relación macho: hembra fue similar. Sin embargo, más crías de sexo macho fueron originadas del ovario izquierdo que del derecho (65.2 vs. 34.8%, respectivamente; p=0.04), aunque los porcentajes de machos nacidos originados de ovulaciones del ovario izquierdo (30/53=56.6%; p=0.33) y ovario derecho (16/39=41.0%; p=0.26) no fueron diferentes de la relación esperada (1:1). La duración de la gestación y el peso vivo al nacimiento fueron estadísticamente similares entre sexos.

Abstract The general objective of this study was to collectively construct the concepts of quality and excellence for a Chilean university as part of the updating of its quality policy, within the framework of the permanent search for continuous improvement within the institution. A theoretical review of both concepts was carried out, which allowed establishing that quality is a widely studied topic in higher education, but not the idea of excellence, which has been researched to a lesser extent. It was determined that a theoretical construction is not sufficient for their definitions, since both concepts have a multidimensionality and are dependent on the context to which they belong. Consequently, it was necessary to highlight the opinions of the different members of the university community in their definition. It was decided to apply a qualitative and exploratory approach based on the opinions of the different strata, where 75 people participated in a survey conducted through focus groups applied in August 2020 and October 2021. Subsequently, a content analysis was carried out, which established the following results: each definition of the concepts must be concrete and include an approach that considers the context and the elements of the university's work, such as objectives, identity, purposes, mission and institutional vision; the definition of the concept of excellence must explicitly include quality, so that the relationship between both definitions is visualized.

Resumen Este estudio tuvo como objetivo general construir colectivamente los conceptos de calidad y de excelencia para una universidad chilena como parte de la actualización de su política de calidad, en el marco de la búsqueda permanente de la mejora continua al interior de la institución. Se realizó una revisión teórica de ambos conceptos, lo que permitió establecer que la calidad es una temática ampliamente estudiada en educación superior, no así la idea de excelencia, que se encuentra investigada en menor medida. Se determinó que no es suficiente una construcción teórica para sus definiciones, ya que ambos conceptos poseen una multidimensionalidad y son dependientes del contexto al que pertenecen. Consecuentemente, fue necesario destacar las opiniones de los diferentes integrantes de la comunidad universitaria en su definición. Se decidió aplicar un enfoque cualitativo y exploratorio a partir de las opiniones de los distintos estamentos, donde participaron 75 personas de un levantamiento realizado a través de grupos focales aplicados en agosto de 2020 y en octubre del año 2021. Posteriormente, se realizó un análisis de contenido que estableció los siguientes resultados: cada definición de los conceptos debe ser concreta e incluir un enfoque que considere el contexto y los elementos propios del quehacer de la universidad, tales como objetivos, identidad, propósitos, misión y visión institucional; la definición del concepto de excelencia debe incluir de manera explícita la calidad, de modo que se visualice la relación entre ambas definiciones.

ABSTRACT Semi-mechanized and mechanized harvesting use machines that promote the transference of vibrational energy and impact to achieve the detachment of coffee fruits. The aim of this study was to evaluate the vibration transmissibility in coffee fruit-peduncle systems, using high-speed cameras, submitted to high frequency harmonic excitation in different combinations between frequency and amplitude of vibration, identifying working ranges suitable to perform selective harvesting. Vibration transmissibility was determined for the coffee fruit-peduncle systems, for the maturation stages unripe and ripe that were subjected to a sinusoidal harmonic displacement, in which the input parameters were frequency (35, 45 and 55 Hz) and peak-to-peak amplitude (3.5, 5.0 and 6.5 mm). An experiment was used to study the effect of frequency and amplitude on vibration transmissibility in a completely randomized design in a factorial scheme 3 x 3 x 2, with three replications. The frequency of 35 Hz, associated with the amplitudes 3.5-6.5 mm, was the one that most influenced the results of vibration transmissibility. For the frequency of 55 Hz and amplitude of 6.5 mm, in the ripe maturation stage, the vibration transmissibility was higher than 1.0, which could be a suitable combination for selective coffee harvesting.

Abstract Background Pharmacoinvasive strategy is an alternative when primary percutaneous coronary intervention (PCI) is not feasible. Objectives This study aimed to evaluate the effects of early pharmacoinvasive strategy on the infarct size and left ventricular ejection fraction in elderly and non-elderly patients. The role of inflammatory markers was also examined. Methods Patients (n=223) with ST segment elevation myocardial infarction (STEMI) were prospectively included and submitted to pharmacological thrombolysis in the first six hours, and underwent coronary angiogram and PCI when necessary, in the first 24 hours. Blood samples were collected in the first day (D1) and after 30 days (D30). Cardiac magnetic resonance imaging (cMRI) was performed at D30. Significance was set at p<0.05. Results Elderly and non-elderly patients showed similar percentage of infarcted mass (13.7 [6.9-17.0] vs. 14.0 [7.3-26.0], respectively, p=0.13) (median [interquartile range]). However, elderly patients had better left ventricular ejection fraction (53 [45-62] vs. 49 [39-58], p=0.025). Titers of interleukin (IL)1beta, IL-4, IL-6, and IL-10 did not differ between D1 and D30, but elderly patients had higher titers for IL-18 at D1 and D30. Absolute numbers of B and T lymphocytes were similar in both groups at D1 and D30, but elderly patients had higher neutrophil/lymphocyte ratio at D30. Multivariate linear regression analysis of cMRI outcomes in the whole population showed that the independent predictors were not different between elderly and non-elderly patients. Conclusion Pharmacoinvasive strategy in elderly patients was associated with small differences in inflammatory parameters, similar infarct size and better left ventricular function than non-elderly patients.

Resumo Fundamento A estratégia farmacoinvasiva é uma alternativa na inviabilidade da intervenção coronária percutânea primária (ICP). Objetivos Este estudo teve como objetivo avaliar os efeitos da estratégia farmacoinvasiva precoce sobre o tamanho da área infartada e a fração de ejeção ventricular esquerda em pacientes idosos e não idosos. O papel dos marcadores inflamatórios também foi avaliado. Métodos Pacientes (n=223) com infarto do miocárdio com elevação do segmento ST (IAMCSST) foram prospectivamente incluídos e submetidos à trombólise medicamentosa nas primeiras seis horas, e à angiografia coronariana e à ICP, quando necessária, nas primeiras 24 horas. As amostras de sangue foram coletadas no primeiro dia (D1) e 30 dias após (D30). A ressonância magnética cardíaca foi realizada no D30. O nível de significância estatística foi estabelecido em p<0,05. Resultados Pacientes idosos e não idosos apresentaram porcentagem similares de massa infartada [13,7 (6,9-17,0) vs. 14,0 (7,3-26,0), respectivamente p=0,13)] [mediana (intervalo interquartil)]. No entanto, os pacientes idosos apresentaram maior fração de ejeção ventricular esquerda [53 (45-62) vs. 49 (39-58), p=0,025)]. As concentrações de interleucina (IL)1beta, IL-4, IL-6, e IL-10 não foram diferentes entre D1 e D30, mas pacientes idosos apresentaram níveis mais elevados de IL-18 em D1 e D30. O número absoluto de linfócitos B e T foram similares em ambos os grupos em D1 e D30, porém, pacientes idosos apresentaram uma razão neutrófilo-linfócito mais alta em D30. A análise de regressão linear multivariada dos desfechos de RMC de toda a população do estudo mostrou que os preditores independentes não foram diferentes entre pacientes idosos e não idosos. Conclusão A estratégia farmacoinvasiva em pacientes idosos foi associada a pequenas diferenças nos parâmetros inflamatórios, tamanho do infarto similar, e melhor função ventricular esquerda em comparação a pacientes não idosos

Abstract The aim of this article is to present evidence of validity for the ‘work-family conflict scale’ with a sample of 10,383 professionals working in Brazilian public security. Cross-validation procedures were applied through the definition of two subsamples, exploratory and confirmatory factor analyses were performed. All ethical procedures were followed. The results found in both the exploratory factor analysis (‘Work Interference with Family’ Factor, with factor loadings between .91 and .81 and alpha of .93, and ‘Family Interference with Work’ Factor, with factor loadings between .96 and .71 and alpha of .90) and the confirmatory analysis (χ2/df <5; CFI >.98; TLI >.98; RMSEA <.10) demonstrate robust evidence of validity, indicating the use of the scale in other organizational contexts.

Resumo O artigo tem como objetivo geral apresentar evidências de validade da escala ‘conflito trabalho-família’ junto a uma amostra de 10.383 profissionais que atuam na segurança pública brasileira. Optou-se pela condução dos procedimentos de validação cruzada, por meio da definição de duas subamostras, foram realizadas análises fatoriais exploratórias e confirmatórias. Todos os procedimentos éticos foram adotados. Os resultados encontrados tanto na análise fatorial exploratória (Fator ‘Interferência do Trabalho na Família’, com cargas fatoriais entre 0,91 e 0,81 e alpha de 0,93 e Fator ‘Interferência da Família no Trabalho, com cargas entre 0,96 a 0,71 e alpha de 0,90) quanto confirmatória (χ2/gl < 5; CFI > 0,98; TLI > 0,98; RMSEA < 0,1) demonstram robustas evidências de validade, indicando o uso da escala em outros contextos organizacionais.

Abstract Background Weight gain can trigger mechanisms that increase blood pressure. Nevertheless, obesity causes structural changes in the myocardium, including increased ventricular mass, atrial dilatation, and diastolic and systolic dysfunction. Additionally, blood pressure variations, like morning surge (MS) in obese hypertensive patients may have clinical relevance in cardiovascular events. Although morning blood pressure surge is a physiological phenomenon, excess MS can be considered an independent risk factor for cardiovascular events. Objective To evaluate MS values and their association with left ventricular hypertrophy (LVH) and nocturnal dipping (ND) in obese and non-obese hypertensive patients. Methods A cross-sectional study that evaluated BP measurements by ambulatory blood pressure monitoring (ABPM) and the presence of LVH by echocardiography in 203 hypertensive outpatients, divided into two groups: 109 non-obese and 94 obese hypertensives patients. The significance level was set at 0.05 in two-tailed tests. Results A MS above 20 mmHg by ABPM was detected in 59.2% of patients in the non-obese group and 40.6% in the obese group. LVH was found in 18.1% and 39.3% of patients in the non-obese and obese groups, respectively, p<0.001. In the “obese group”, it was observed that a MS>16 mmHg was associated with LVH, [prevalence ratio: 2.80; 95%CI (1.12–6.98), p=0.03]. For the non-obese group, the cut-off point of MS for this association was >22 mmHg. Conclusion High MS was positively associated with LVH, with a particular behavior in the hypertensive obese group.

Resumo Fundamento O aumento do peso frequentemente desencadeia mecanismos que elevam a pressão arterial. A obesidade causa mudanças estruturais no miocárdio, incluindo aumento da massa ventricular, dilatação atrial, bem como disfunções diastólicas e sistólicas. Além disso, variações pressóricas nos hipertensos obesos, como a ascensão matinal (AM), podem ter relevância clínica na prevenção dos eventos cardiovasculares. A AM da pressão arterial é um fenômeno fisiológico, que quando elevada pode ser considerada um fator de risco independente para eventos cardiovasculares. Objetivo Avaliar valores da elevação da AM e sua associação com a hipertrofia ventricular esquerda (HVE) e com o Descenso do Sono (DS) em obesos e não obesos hipertensos. Métodos Estudo transversal que avaliou medidas pressóricas à monitorização ambulatorial da pressão arterial (MAPA) e a presença de HVE, avaliada pela ecocardiografia, em 203 pacientes hipertensos em tratamento ambulatorial, separados em dois grupos: 109 não obesos e 94 hipertensos obesos. O nível de significância adotado foi de 0,05 em testes bicaudais. Resultados A AM acima de 20 mmHg à MAPA foi detectada em 59,2% dos pacientes do grupo “não obesos” e em 40,6% no grupo “obesos”. A HVE foi encontrada em 18,1% no grupo dos não-obesos e em 39,3% no grupo de obesos, p<0,001. No grupo “obesos” foi observado que AM >16 mmHg esteve associada à HVE, com [razão de prevalência: 2,80; IC95% (1,12–6,98), p=0,03]. Para o grupo dos “não obesos”, o ponto de corte da AM para essa associação foi >22 mmHg. Conclusão A AM elevada associou-se positivamente com HVE, com comportamento peculiar na população de hipertensos e obesos.

Asymmetric addition of organozinc compounds to carbonyl groups is one of the most useful methods for the synthesis of alcohols with high enantioselectivity. There is a wide range of chiral catalysts, although their synthesis requires more than one step and not often readily available starting materials. In this work, chiral β-hydroxy oxazolines derived from (+)-camphor and (-)-fenchone were easily synthesized through a one-step method, with good yields. Both ligands were evaluated as catalysts for the stereoselective addition of diethylzinc to aromatic aldehydes. All ligands showed good catalytic activity, leading both to the preparation of the R enantiomer of chiral secondary alcohols. As ligand 2 provided slightly better enantioselectivities, it was used as chiral inductor for the addition of diethylzinc for a larger number of aldehydes, resulting in good to excellent yields (88-98%) and enantiomeric excess up to 96%.

Abstract The geographical distribution of sand flies in Brazil has been the subject of some studies, yet there is no information about the phlebotomine fauna in João Pessoa, State of Paraíba, Brazil. The aim of this work is to evaluate the occurrence and distribution of sand flies in the Atlantic forest fragments and to evaluate a possible dispersion in 06 nearby districts. Light traps were used during three consecutive nights, supplemented by an aspirator during the dry period and rainy season. A total of 222 sand flies were found, 143 (130 males and 13 females) in the Atlantic forest, and 79 in urban areas. During the entire dry season, three species of phlebotomine sand flies were recorded in 11 forest fragments, Lutzomyia longipalpis, Lu. migonei and Lu. whitmani. During the rainy season, only Lu. longipalpis was found. This was the only species identified in the studied neighborhoods during both seasons. The differences in diversity of sand flies encountered between natural habitats and urban areas may thus be correlated mostly with adaptations to particular habitats and availability of food. One species (Lu. longipalpis) appears to be rapidly adapting to urban areas because of deforestation.

ABSTRACT An adequate use of brackish water in agricultural production is one of the main challenges for researchers and rural producers, since saline stress may cause physiological and nutritional changes in plants, affecting the crop yield. An appropriate mineral nutrition is essential for plants, grown under saline stress, to express their productive potential. The aim of this study was to evaluate the mineral nutrition and hydroponic kale production under saline stress and calcium nitrate. The experiment was carried out using one hydroponic system in substrate, following a randomized block design, with five treatments and four replicates. The treatments consisted of five nutrient solutions, with a control treatment {S1 = standard nutrient solution using low salinity water, 0.5 dS/m [750 mg/L of Ca(NO3)2]}, and four nutrient solutions prepared using brackish water (6.0 dS/m) containing four concentrations of Ca(NO3)2 (S2 = 750 mg/L, S3 = 1,125 mg/L, S4 = 1,500 mg/L, S5 = 1,875 mg/L). We determined the levels of N, P, K, Ca, Mg and S in leaf tissue at three evaluation times (50, 64 and 78 DAT). Mineral levels in the leaves, stem and root were also evaluated at the end of the experiment (100 DAT). In addition, leaf production and the agronomic efficiency of Ca(NO3)2 were verified. The highest leaf production (1780 g/plant) and agronomic efficiency [2.37 g fresh matter/mg of Ca(NO3)2] were obtained in the standard nutrient solution, and both were reduced at 55.6% by salinity. The extra addition of 50% Ca(NO3)2 in the saline nutrient solution reduced the effect of salinity on Mg absorption and the effect of NaCl addition on kale production.

RESUMO O uso de águas salobras na produção agrícola é um dos principais desafios para pesquisadores e produtores rurais, pois sob estresse salino as plantas podem apresentar alterações fisiológicas e nutricionais, que afetam o rendimento das culturas. Com isso, adequada nutrição mineral é fundamental para que as plantas cultivadas sob estresse salino possam expressar seu potencial produtivo. Objetivou-se com o presente estudo avaliar a nutrição mineral e a produção de couve folha hidropônica sob estresse salino e nitrato de cálcio. O experimento foi desenvolvido utilizando um sistema hidropônico em substrato, seguindo o delineamento de blocos casualizados, com cinco tratamentos e quatro repetições. Os tratamentos foram compostos por cinco soluções nutritivas, sendo um tratamento controle {S1 = solução nutritiva padrão usando água de baixa salinidade, 0,5 dS/m [750 mg/L de Ca(NO3)2]}, e quatro soluções nutritivas preparadas em águas salobras (6,0 dS/m) contendo quatro concentrações de Ca(NO3)2 (S2 = 750 mg/L, S3 = 1.125 mg/L, S4 = 1.500 mg/L, S5 = 1.875 mg/L). Foram determinados os teores de N, P, K, Ca, Mg e S no tecido foliar em três épocas de avaliações (50, 64 e 78 DAT), além de uma avaliação dos teores minerais nas folhas, caule e raiz ao final do experimento (100 DAT). As variáveis produção de folhas e eficiência agronômica do Ca(NO3)2 foram avaliadas. A maior produção de folhas (1780 g/planta) e eficiência agronômica [2,37 g matéria fresca/mg de Ca(NO3)2] foram obtidas na solução nutritiva padrão, e ambas foram reduzidas em 55,6% pela salinidade. A adição extra de Ca(NO3)2 em 50% na solução nutritiva salinizada reduziu o efeito da salinidade sobre a absorção de Mg e reduziu o efeito da adição de NaCl sobre a produção da couve.

RESUMO O fósforo tem importância fundamental para o suprimento energético necessário para o metabolismo vegetal, mas ainda é pouco estudado em culturas importantes, como a mandioca. Objetivou-se avaliar o acúmulo e a eficiência do uso do fósforo em diferentes cultivares de mandioca no semiárido. Foram conduzidos dois experimentos em duas safras agrícolas, 2018/2019 e 2019/2020, em Mossoró-RN. O delineamento experimental foi em blocos ao acaso, em parcelas subdivididas, com quatro repetições. Nas parcelas, foram aplicadas no sulco de cultivo cinco doses de fósforo (P) (0; 60; 120; 180 e 240 kg ha-1 de P2O5), e, nas subparcelas quatro cultivares de mandioca (Água Morna, BRS Gema de Ovo, Recife e Venâncio). As cultivares Água Morna e Recife exportam mais fósforo através de suas raízes. As cultivares Venâncio e Água Morna apresentam maior eficiência agronômica quando adubadas com 60 kg ha-1 de P2O5. A eficiência aparente de recuperação do P apresentou a seguinte ordem: ‘BRS Gema de Ovo’ > ‘Água Morna’ > ‘Venâncio’ > ‘Recife’, com maiores índices na dose de 60 kg ha-1 de P2O5.

ABSTRACT Phosphorus is of fundamental importance for the energy supply necessary for plant metabolism, but it is still understudied for important agricultural crops such as cassava. The objective of this study was to evaluate the accumulation and efficiency of phosphorus use in different cassava cultivars in the semiarid region. Two experiments were carried out during two agricultural seasons 2018/2019 and 2019/2020 in Mossoró, Rio Grande do Norte state, Brazil. The experimental design was randomized blocks, in split plots, with four replicates. In the plots, five doses of phosphorus (P) (0, 60, 120, 180, and 240 kg ha-1 of P2O5) were applied in the planting furrow, and four cassava cultivars (Água Morna, BRS Gema de Ovo, Recife, and Venâncio) were cultivated in the subplots. The cultivars Água Morna and Recife export more phosphorus through their roots. The cultivars Venâncio and Água Morna show greater agronomic efficiency when fertilized with 60 kg ha-1 of P2O5. The apparent P recovery efficiency presented the following order: ‘BRS Gema de Ovo’ > ‘Água Morna’ > ‘Venâncio’ > ‘Recife’, with higher indices at the dose of 60 kg ha-1 of P2O5.