ABSTRACT The objective of the present work was to evaluate the influence of environmental variables on the interaction between genotypes and environments and to identify adapted and stable genotypes for grain seed yield. Twenty-one cultivars were evaluated in randomized blocks with four replications in the years 2016, 2017, and 2018 in the northeastern semi-arid region of Brazil, for seed yield and oil content. Factor regression methodologies and principal component analysis were used with predictions of the sum of the genotypic effects and the interaction to quantify the role of five environmental covariates in the genotype x environment interaction; the Harmonic Mean Method of Relative Performance of Genotypic Values was used for identifying adapted and stable genotypes. The covariance biplot model is useful for relating important environmental factors and indicating their relative effect on seed yield and oil content. Rainfall, relative humidity and maximum temperature contribute positively to increasing oil content while minimum temperature and solar radiation reduce it. Within the limits of the work, the maximum temperature positively influences grain production while the minimum reduces it. The most stable genotypes and those adapted for grain seed yield and oil content are BMX OPUS IPRO, P 98Y70 RR, BRS 333 RR, BRS 9280 RR, M 8644 IPRO, M 8372 IPRO, and ST 920 RR.

RESUMO O objetivo do presente trabalho foi avaliar a influência de variáveis ambientais na interação entre genótipos e ambientes e identificar genótipos adaptados e estáveis para a produção de sementes. Vinte e uma cultivares foram avaliadas em blocos ao acaso com quatro repetições nos anos de 2016, 2017 e 2018 no semiárido nordestino do Brasil, para rendimento de sementes e teor de óleo. Metodologias de regressão fatorial e análise de componentes principais foram utilizadas com previsões da soma dos efeitos genotípicos e a interação para quantificar o papel de cinco covariáveis ambientais na interação genótipo x ambiente; o Método da Média Harmônica de Desempenho Relativo de Valores Genotípicos foi usado para identificar genótipos adaptados e estáveis. O modelo biplot de covariância é útil para relacionar fatores ambientais importantes e indicar seu efeito relativo no rendimento de sementes e no teor de óleo. A precipitação, a umidade relativa e a temperatura máxima contribuem positivamente para aumentar o teor de óleo, enquanto a temperatura mínima e a radiação solar o reduzem. Dentro dos limites do trabalho, a temperatura máxima influencia positivamente a produção de grãos enquanto a mínima a reduz. Os genótipos mais estáveis e adaptados para rendimento de sementes de grãos e teor de óleo são BMX OPUS IPRO, P 98Y70 RR, BRS 333 RR, BRS 9280 RR, M 8644 IPRO, M 8372 IPRO e ST 920 RR.

RESUMO Como alimento fresco, a batata-doce se destaca pelo sabor e aparência. Na indústria, é valorizado por seu teor de amido e açúcar. Em ambos os cenários, muita atenção tem sido dada à composição dos compostos bioativos. A aplicação de estresses abióticos parece induzir uma superprodução desses compostos em algumas hortaliças. O objetivo foi examinar a influência da época de colheita na síntese e acúmulo de compostos bioativos em variedades de batata-doce minimamente processadas com diferentes cores de polpa. As cultivares de batata-doce: Beterraba, Jerimum, Mãe de Família Roxa e BRS Cuia foram colhidas aos 120, 150 e 180 dias após o plantio, submetidas ao processamento mínimo e armazenadas a 5 ºC por 10 dias. A época mais recomendada para a colheita da batata-doce em condições semi-áridas para a indústria de processamento mínimo foi entre 150 e 180 dias, período em que a batata-doce apresentou melhor qualidade para consumo in natura em destaque para 'Mãe de Família Roxa' e 'Jerimum'. A ‘BRS Cuia’ colhida aos 120 dias apresentou os maiores teores de compostos fenólicos, as maiores atividades das enzimas polifenoloxidase e peroxidase e os sintomas de escurecimento mais intensos, podendo ser utilizado como matéria-prima para a extração de compostos fenólicos de interesse, além do amido. A ‘Beterraba’ apresentou baixos valores de açúcar, tornandoos desfavoráveis para consumo in natura ou processamento mínimo. No entanto, esta cultivar também apresentou um alto teor de carotenóides, tornando-os biofábricas para as indústrias alimentícia e farmacêutica.

ABSTRACT As a fresh food, sweet potatoes are highlighted for their taste and appearance. In the industry, they are valued for their starch and sugar content. In both scenarios, much attention has been given to the composition of bioactive compounds. The application of abiotic stresses seems to induce an overproduction of these compounds in some vegetables. The objective was to examine the influence of harvest time on the synthesis and accumulation of bioactive compounds in varieties of minimally processed sweet potatoes with different flesh colors. Sweet potato cultivars (Beterraba, Jerimum, Mãe de Família Roxa, and BRS Cuia) were harvested at 120, 150, and 180 days after planting, then subjected to minimal processing and stored at 5 ºC for 10 days. The most recommended time for harvesting sweet potatoes in semi-arid conditions for minimal processing by the industry is between 150 and 180 days. This is the period when the sweet potatoes exhibit the best quality for fresh consumption, as detected in ‘Mãe de Família Roxa’ and ‘Jerimum’. ‘BRS Cuia’ harvested at 120 days showed the highest phenolic compound levels, the highest polyphenol oxidase and peroxidase enzyme activities, and the most intense browning symptoms. In addition to its starch content, it can be used as a raw material for the extraction of phenolic compounds of interest. ‘Beterraba’ showed low sugar values, rendering them unfavorable for fresh consumption or minimal processing. However, this cultivar also exhibited a high content of carotenoids, making them bio-factories for the food and pharmaceutical industries.

RESUMO A melancia apresenta grande relevância econômica, no entanto, fatores edafoclimáticos e manejo inadequado vem favorecendo a salinização da água utilizada para irrigação, sendo este um fator limitante para o crescimento e produção da cultura. Contudo, considera-se que a utilização de reguladores de crescimento pertencentes ao grupo das citocininas e auxinas, pode contribuir para o desenvolvimento e produtividade das lavouras, mesmo em condições adversas como a salinidade. Assim, objetivou-se avaliar a influência de proporções de citocinina e auxina no crescimento e na qualidade de melancia irrigada com água salina. O delineamento experimental foi inteiramente casualizado, com quatro repetições e fatorial 5 x 2, sendo cinco proporções de reguladores de crescimento (0/100; 25/75; 50/50; 75/25 e 100/0%) correspondentes às concentrações 1,0 e 10,0 mg L−1 de forchlorfenuron CPPU / ácido indolacético (IAA), e dois níveis de salinidade, um composto da água sem adição de sal (0,3 dS m−1) e outro com condutividade elétrica de 2,0 dS m −1. As proporções de citocinina e auxina influenciaram no crescimento e qualidade de melancia submetida à salinidade na água de irrigação. A proporção 25/75% (CPPU/IAA) favoreceu menores decréscimos na área foliar e na massa seca total em condição salina de 2,0 dS m−1. Para massa fresca e seca do fruto, a proporção 75/25% (CPPU/IAA) favoreceu menores reduções. A firmeza do fruto e os sólidos solúveis foram favorecidos pelas proporções 25/75 e 50/50% (CPPU/IAA) em EC de 2.0 dS m−1. A acidez só foi influenciada pela proporção de 50/50% (CPPU/IAA) entre os níveis de condutividade elétrica.

ABSTRACT Watermelon has great economic relevance, but edaphoclimatic factors and inadequate management have favored the salinization of the water used for irrigation, which is a limiting factor for the growth and production of the crop. However, it is considered that the use of growth regulators belonging to the group of cytokinins and auxins may contribute to the development and yield of crops, even under adverse conditions such as salinity. Thus, the objective was to evaluate the influence of cytokinin and auxin proportions on the growth and quality of watermelon irrigated with saline water. The experimental design was completely randomized, with four replicates and 5 x 2 factorial, referring to five proportions of growth regulators (0/100; 25/75; 50/50; 75/25 and 100/0%) corresponding to concentrations of 1.0 and 10.0 mg L−1 of forchlorfenuron (CPPU)/ indoleacetic acid (IAA), and two salinity levels, one composed of water without adding salt (0.3 dS m-1) and the other with 2.0 dS m−1 electrical conductivity. The proportions of cytokinin and auxin influenced the growth and quality of watermelon subjected to salinity in irrigation water. The 25/75% (CPPU/IAA) proportion favored smaller decreases in leaf area and total dry mass under a saline condition of 2.0 dS m−1. For fresh and dry fruit mass, the 75/25% (CPPU/IAA) proportion favored smaller reductions. Fruit firmness and soluble solids were favored by the proportions 25/75 and 50/50% (CPPU/IAA) at EC of 2.0 dS m−1. Acidity was only influenced by the proportion of 50/50% (CPPU/IAA) between the electrical conductivity levels.

Resumen El objetivo del presente trabajo fue evaluar la influencia de la interacción genotipo por ambiente en estudios de divergencia genética en soja en condiciones semiáridas. Se realizaron cuatro experimentos con un diseño de bloques completos aleatorizados con cuatro repeticiones donde se evaluaron 21 genotipos de soja. Se utilizaron los siguientes descriptores para cuantificar la divergencia: altura de planta, materia seca, contenido de aceite, número de vainas por planta, número de granos por vaina, peso de cien semillas, rendimiento, días a floración y días a maduración. Se utilizó el método jerárquico UPGMA para agrupar los genotipos de la matriz de distancias de Mahalanobis mediante las medias genotípicas estimadas por el método REML / BLUP. La agrupación de genotipos depende de las condiciones de evaluación, principalmente debido a los efectos de la interacción genotipo por años. El análisis conjunto, sin la presencia del efecto de interacción, permite obtener dos grupos de genotipos. Los cruzamientos más adecuados involucran los genotipos BRS Tracajá, BRS Pérola, BRS Carnaúba, M 8644 IPRO, BRS 8590 y BMX OPUS IPRO, y el genotipo BRS Sambaíba, especialmente el entre BMX OPUS IPRO y el genotipo BRS Sambaíba, que es el de mayor disimilitud.

Abstract The objective of the present work was to evaluate the influence of the genotype-envi ronment interaction on genetically divergent soybean grown under semiarid conditions. Four experiments were carried out in randomized blocks with four replicates to evaluate twenty-one soybean genotypes. The following descriptors were used to quantify diver gence: plant height, dry matter, oil content, number of pods per plant, number of grains per pod, the weight of 100 seeds, yield, days for flowering, and days for maturation. The unweighted pair group method with arithmetic mean was used to group the genotypes from the Mahalanobis distance matrix estimated using the genotypic means estimated by the REML/BLUP method. The grouping of genotypes depended mainly on the effects of the interaction between genotypes and years. The joint analysis, without the effect of the inter action, allowed us to obtain two groups of genotypes. The most recommended crosses were those of the lines BRS Tracajá, BRS Pérola, BRS Carnaúba, M 8644 IPRO, BRS 8590, and BMX OPUS IPRO with the genotype BRS Sambaíba, especially the one between BMX OPUS IPRO and BRS Sambaíba.

ABSTRACT The determination of leaf area is fundamental for studies related to plant growth and physiology. Thus, non-destructive methods allow an accurate estimate of the leaf area through linear dimensions of the leaves. The research objective was to construct allometric equations to estimate the leaflet area of peanut cultivars. Then, 2,605 leaflets were collected from six peanut cultivars (IAC Caiapó, IAC 8112, Runner IAC 886, BRS Havana, BRS 151 L7, and IAC Tatuí), with more than 400 leaflets sampled for each cultivar. We measured the length, width, product between length and width, and leaflet area. Linear and non-linear models (linear, linear without intercept, power, and exponential) were built, and the best equation was chosen using the statistical criteria: highest coefficient of determination (R2), Pearson’s linear correlation coefficient (r), Willmott’s agreement index (d), lowest Akaike information criterion (AIC), and root mean square of the error (RMSE). It was found that the models that used the product between length and width were the most suitable for estimating the leaflet area of peanut cultivars. Given the little intraspecific morphological variability, it was possible to group the cultivars, and model y ^ = 0.875 * LW0.929 was indicated to estimate the peanut leaflet area accurately, regardless of the cultivar.

RESUMO A utilização da adubação verde com o uso de espécies espontâneas tem ganhando destaque no cultivo de hortaliças, visando a sustentabilidade do ambiente e sendo um método alternativo para o Semiárido nordestino. Dois experimentos foram conduzidos em duas épocas de cultivo (outono e primavera-verão), em Serra Talhada, PE, Brasil, a fim de se avaliar os efeitos de quantidades de biomassa e tempos de incorporação de Calotropis procera (Flor-de-seda) no desempenho agroeconômico da beterraba. O delineamento experimental utilizado foi em blocos casualizados, com três repetições. Os tratamentos foram arranjados em esquema fatorial 4 × 4 , sendo o primeiro fator correspondente às quantidades de C. procera (5,4; 8,8; 12,2 e 15,6 Mg ha-1 em base seca) e o segundo, aos tempos de incorporação ao solo (0, 10, 20 e 30 dias antes da semeadura da beterraba). Além da produtividade comercial de raízes e dos custos de produção, foram determinados: renda bruta, renda líquida, taxa de retorno e índice de lucratividade. A quantidade de 15,6 Mg ha-1 de C. procera promoveu as maiores rendas bruta e líquida, enquanto que as quantidades de 5,4 e 12,2 Mg ha-1 obtiveram as melhores taxas de retorno e índices de lucratividade no outono e primavera-verão, respectivamente, sendo considerada ideal a adubação realizada no momento do plantio. O cultivo de primaveraverão possibilitou retorno econômico superior à semeadura de outono. Independente dos fatores, o uso da C. procera como adubo verde na produção de beterraba foi viável agroeconomicamente.

ABSTRACT The use of green manure from spontaneous species has gained prominence for vegetable crops focused on environmental sustainability and is an alternative method for the Semiarid region in the Northeast of Brazil. Two experiments were conducted in two growing seasons (autumn and spring-summer), in Serra Talhada, PE, Brazil, to evaluate the effects of different amounts of biomass of Calotropis procera (roostertree) and incorporation times on the agro-economic performance of beet crops. A randomized block experimental design was used, with three replications, in a 4 × 4 factorial arrangement; the first factor consisted of amounts of C. procera biomass (5.4, 8.8, 12.2, and 15.6 Mg ha-1 on a dry basis) and the second factor consisted of times of incorporation into the soil (0, 10, 20, and 30 days before planting beet). Commercial root yield, production costs, and the following economic indicators were determined: gross income, net income, return rate, and profitability index. The use of 15.6 Mg ha-1 of C. procera biomass resulted in the highest gross and net incomes and the use of 5.4 and 12.2 Mg ha-1 resulted in the best return rates and profitability indexes in autumn and spring-summer seasons, respectively; the planting time was considered as ideal for the biomass incorporation. The spring-summer growing season resulted in a higher economic return than the autumn growing season. The use of C. procera as a green manure for beet production is economically viable, regardless of the factors evaluated.

RESUMO Os parâmetros de qualidade de raízes de mandioca variam entre cultivares e em função de fatores abióticos, como a nutrição das plantas. Porém, a magnitude com a qual esses fatores interferem ainda não está bem definida, especialmente para o fósforo (P), que é um nutriente diretamente ligado à síntese de açúcares e amido nas plantas. Assim, o objetivo da pesquisa foi avaliar a qualidade de raízes de cultivares de mandioca de mesa adubadas com doses de P no Semiárido brasileiro. A pesquisa foi realizada na Fazenda Experimental Rafael Fernandes, Mossoró, RN, Brasil, no período de junho/2018 a abril/2019. O delineamento experimental utilizado foi em blocos casualizados, arranjados em parcelas subdivididas, com quatro repetições. Nas parcelas, foram aplicadas as doses de P (0, 60, 120, 180 e 240 kg ha-1 de P2O5), e nas subparcelas, as cultivares de mandioca de mesa (Água Morna, BRS Gema de Ovo, Recife e Venâncio). Foram avaliadas: firmeza, elasticidade, acidez titulável, sólidos solúveis, açúcares solúveis totais, amido e tempo de cocção. A qualidade das raízes de mandioca de mesa variou em função da cultivar e da dose de P. Doses de P entre 120 e 240 kg ha-1 de P2O5 proporcionam aumento no teor de amido e redução do tempo de cocção de raízes de mandioca de mesa.

ABSTRACT The quality parameters of cassava roots vary between cultivars and depend on abiotic factors, such as plant nutrition. However, the magnitude of how these factors interfere is not yet well defined, especially for phosphorus (P), which is a nutrient directly linked to the synthesis of sugars and starches in plants. Thus, the objective of the research was to evaluate the quality of roots of table cassava cultivars fertilized with doses of P in the Brazilian semiarid. The research was carried out at the Rafael Fernandes experimental farm, Mossoró, RN, Brazil, from June 2018 to April 2019. The experimental design used was in randomized blocks, arranged in subdivided plots and with four replications. Doses of P (0, 60, 120, 180 and 240 kg ha-1 of P2O5) were applied in the plots, and in the subplots, the table cassava cultivars (Água Morna, BRS Gema de Ovo, Recife and Venâncio). Firmness, elasticity, titratable acidity, soluble solids, total soluble sugars, starch and cooking were all evaluated. The quality of table cassava roots varied depending on the cultivar and the dose of P. Doses of P between 120 and 240 kg ha-1 of P2O5 increase the starch content and reduce the cooking time of table cassava roots.

ABSTRACT The sesame crop has great economic potential due to the various possibilities of exploitation, however, there is a lack of information about the chemical control of weeds in the crop, mainly about the application of herbicides in pre-emergence. Therefore, the objective of this study was to evaluate the economic viability and efficacy of herbicides applied in pre-emergence for the control of weeds in the sesame crop. The experimental design was in randomized blocks, with four replications. The treatments consisted of seven herbicides (diuron, flumioxazin, oxadiazon, oxyfluorfen, metribuzin, linuron, and S-metolachlor) and a mixture (metribuzin + oxyfluorfen) applied in pre-emergence. The two control treatments were weeded and nonweeded plots. The variables evaluated were percentage of control of the weed community, grain yield, gross and net income, rate of return, and profitability index. The highest productivity value was for weeding, followed by the herbicides diuron and flumioxazin, with 2,000.44 kg ha-1, 1,957.35 kg ha-1;, and 1,933.13 kg ha-1, respectively. The herbicides diuron and flumioxazin obtained the highest net income, in the amounts of R$ 7,831.26 and R$ 7,762.85, respectively. The diuron and flumioxazin applied in pre-emergence showed more than 80% in the control of weeds in the sesame crop, showing efficiency in the control. The use of herbicides applied in pre-emergence to control weeds, mainly diuron and flumioxazin, is as efficient as mechanical control, demonstrating the potential for use and economic viability in relation to mechanical control, which presents a high cost/benefit ratio.

RESUMO A cultura do gergelim apresenta grande potencial econômico por conta das diversas possibilidades de exploração, contudo há carências de informações a respeito do controle químico de plantas daninhas na cultura, principalmente sobre a aplicação de herbicidas em pré-emergência. Sendo assim, o objetivo deste estudo foi avaliar a viabilidade econômica e a eficácia de herbicidas aplicados em pré-emergência para o controle de plantas daninhas na cultura do gergelim. O delineamento experimental foi em blocos casualizados, com quatro repetições. Os tratamentos foram constituídos de sete herbicidas (diuron, flumioxazin, oxadiazon, oxyfluorfen, metribuzin, linuron e S-metolachor) e uma mistura (metribuzin + oxyfluorfen) aplicados em préemergência. Os dois tratamentos testemunhas foram as parcelas capinadas e não capinadas. As variáveis avaliadas foram porcentagem de controle da comunidade infestante, produtividade de grãos, rendas bruta e líquida, taxa de retorno e índice lucratividade. O maior valor de produtividade foi para o tratamento capinado, seguido dos herbicidas diuron e flumioxazin, com 2.000,44 kg ha-1, 1.957,35 kg ha-1 e 1.933,13 kg ha-1, respectivamente. Os herbicidas diuron e flumiozaxin obtiveram as maiores rendas líquidas, nos montantes de R$ 7.831,26 e R$ 7.762,85, respectivamente. O diuron e flumioxazin aplicados em pré-emergência apresentaram mais de 80% no controle de plantas daninhas na cultura do gergelim, demostrando eficiência no controle. O uso de herbicidas aplicados em pré-emergência para o controle de plantas daninhas, principalmente o diuron e flumioxazin, é tão eficiente quanto o controle mecânico, demonstrando potencial de uso e viabilidade econômica em relação ao controle mecânico que apresenta custo/benefício elevado.

Resumo: O objetivo deste trabalho foi avaliar a eficiência agroeconômica de sistemas consorciados de feijão-caupi verde e rabanete, em ambiente semiárido brasileiro. Os experimentos foram realizados em duas safras agrícolas, em delineamento de blocos ao acaso, com quatro repetições. Os tratamentos consistiram de um arranjo fatorial 4x2, para a combinação de quatro cultivares de feijão-caupi (Vigna unguiculata) (BRS Tumucumaque, BRS Cauamé, BRS Guariba e BRS Itaim) com duas cultivares de rabanete (Raphanus sativus) (Crimson Gigante e Zapp). Os índices agroeconômicos ‒ índice de produtividade do sistema (IPS), coeficiente equivalente de terra (CET) e razão equivalente monetária (REM) ‒ foram obtidos em parcelas de cultivo solteiro de cada cultivar, em cada bloco. 'BRS Tumucumaque' e 'BRS Guariba' apresentaram a maior produtividade de vagens verdes de feijão-caupi, e 'Crimson Gigante' mostrou a maior produtividade de raízes comerciais de rabanete. O cultivo do feijão-caupi 'BRS Tumucumaque' ou 'BRS Guariba' com o rabanete 'Crimson Gigante' proporciona maior eficiência agroeconômica e sustentabilidade ao consórcio de feijão-caupi verde com rabanete.

Abstract: The objective of this work was to evaluate the agro-economic efficiency of immature cowpea-radish intercropping systems in a semiarid environment in Brazil. The experiments were carried out in two cropping seasons, in a randomized complete block design with four replicates. The treatments consisted of a 4x2 factorial arrangement for the combination of four cowpea (Vigna unguiculata) cultivars (BRS Tumucumaque, BRS Cauamé, BRS Guariba, and BRS Itaim) and two radish (Raphanus sativus) cultivars (Crimson Gigante and Zapp). The agro-economic indices - system productivity index (SPI), land equivalent coefficient (LEC), and monetary equivalent ratio (MER) - were obtained using single plots of each cultivar in each block. 'BRS Tumucumaque' and 'BRS Guariba' showed the highest productivity of immature cowpea pods, and 'Crimson Gigante' showed the highest yield of marketable radish roots. The cultivation of either 'BRS Tumucumaque' or 'BRS Guariba' cowpea with 'Crimson Gigante' radish provides a greater agro-economy efficiency and sustainability for immature cowpea-radish intercropping.

Resumo: O objetivo deste trabalho foi avaliar o desempenho agroeconômico do gergelim (Sesamum indicum) sob fertirrigação com nitrogênio na região semiárida do Nordeste brasileiro. O delineamento experimental foi em blocos ao acaso, com quatro repetições, e os tratamentos foram dispostos em arranjo de parcelas subdivididas, em que as parcelas receberam cinco doses de N (0, 30, 60, 90 e 120 kg ha-1) e as subparcelas foram representadas por quatro genótipos de gergelim ('CNPA G2', 'CNPA G3', 'CNPA G4' e 'BRS Seda'). As seguintes variáveis foram avaliadas em duas safras agrícolas, em 2016: rendas bruta e líquida, taxa de retorno e margem de lucro. Nas duas safras, houve variação nos custos de produção entre as doses de N. Na segunda safra, os maiores valores de renda líquida foram obtidos com 120 kg ha-1 de fertirrigação com N, a saber: R$ 7.428,36 ha-1 para 'CNPA G2', R$ 8.630,74 ha-1 para 'CNPA G3', R$ 9.828,64 ha-1 para 'CNPA G4' e R$ 8.354,06 ha-1 para 'BRS Seda'. Doses crescentes de N proporcionam aumento na renda bruta, na renda líquida, na taxa de retorno e no índice de lucratividade para produtores de gergelim. A fertirrigação com 120 kg ha-1 de N proporciona o máximo desempenho agroeconômico para o gergelim, enquanto o genótipo 'CNPA G4' apresenta a maior eficiência agroeconômica.

Abstract: The objective of this work was to evaluate the agro-economic performance of sesame (Sesamum indicum) under nitrogen fertigation in the semiarid region of Northeastern Brazil. The experimental design was randomized complete blocks with four replicates, and the treatments were arranged in a split-plot, where the plots were assigned five N rates (0, 30, 60, 90, and 120 kg ha-1) and the sub-plots were represented by four sesame genotypes ('CNPA G2', 'CNPA G3', 'CNPA G4', and 'BRS Seda'). The following variables were evaluated in two agricultural harvests in 2016: gross and net incomes, rate of return, and profit margin. In both harvests, there was a variation in production costs between N rates. In the second harvest, the highest values of net income were achieved with 120 kg ha-1 N fertigation, being: R$7,428.36 ha-1 for 'CNPA G2', R$8,630.74 ha-1 for 'CNPA G3', R$9,828.64 ha-1 for 'CNPA G4', and R$8,354.06 ha-1 for 'BRS Seda'. Increasing N rates provide an increase in the gross income, net income, rate of return, and profit margin for sesame producers. Fertigation with 120 kg ha-1 N provides the maximum agro-economic performance for sesame, whereas the 'CNPA G4' genotype shows the greatest agro-economic efficiency.

ABSTRACT Producers in the northeastern semiarid region of Brazil have been cultivating irrigated corn. The commercialized product comprises mainly green ears and silage. However, the irrigation of crops for dry grain has been questioned regarding costs and price competitiveness in relation to the same non-irrigated product cultivated in other regions. In recent years, the use of drip tapes and fertigation has spread among corn producers in the region. The aim of this study was to determine the N dose, via fertigation, which provides the maximum economic production of corn for dry grain, in two crop seasons (summer and winter), in the semiarid region of Brazil. The experimental design was performed in randomized blocks, with four replications. In both crops, the treatments consisted of four doses of N (0, 80, 160, and 240 kg ha-1) applied in the form of urea. In the hybrid corn (Bt Feroz), the N content was evaluated in terms of leaves, grain yield, gross and net incomes, the rate of return, and the profitability index. Independent of the crop season, the yield of dry grain (5,441.03 kg ha-1) was highest when the corn was fertigated with a dose of 104.05 kg ha-1 N. The highest net incomes of the dry grain were obtained with 80 kg ha-1 N in summer (R$ 1,190.78 ha-1) and 160 kg ha-1 N in winter (R$ 2,757.54 ha-1). The winter crop was more favorable to the economic production of dry grain.

RESUMO O objetivo deste trabalho foi avaliar genótipos de abóbora de leite e jerimum caboclo para resistência ao fungo Macrophomina phaseolina (Taissi) Goid. Foram utilizados 17acessos de Cucurbita moschata Duchesne and 20 de Cucurbita máxima Duchese. Também foram utilizadas quatro testemunhas comerciais, duas para cada espécie. Em ambos os trabalhos, inoculou-se três isolados de M. phaseolina que estão mantidos na Micoteca da UFERSA: MM1531 (GenBank: MN136199), ME249 e ME250. As plantas receberam inóculo do patógeno em pedaços de palito de dente colonizado, e foram avaliadas quanto a incidência e severidade da doença. Ambas as espécies apresentaram plantas resistentes, porém com frequências variadas para os acessos. Quando consideradas as espécies, as frequências verificadas para C. Moschata foram superiores às constatadas para C. maxima. Os acessos de C. moschata ABPUN 206 F1, P114-1, P160-2, P11-2, P114-6, P114-02 e P97-1 apresentam diferentes níveis de resistência a Macrophomina phaseolina para os isolados MM1531, ME-249 e ME-250. Assim, para a seleção eficiente em programa de melhoramento para a característica, as estratégias de seleção adotadas devem considerar cada fonte de resistência isoladamente e não cada espécie.

ABSTRACT The objective of this study was to evaluate genotypes of Cucurbita moschata and Cucurbita maxima for resistance to the fungus Macrophomina phaseolina (Taissi) Goid. The experiment evaluated 17 accessions of Cucurbita moschata Duchesne and 20 accessions of Cucurbita maxima Duchesne preserved in the Cucurbit Germplasm Collection of the Federal Rural University of the Semi-Arid Region (UFERSA). Four commercial controls were also used, two for each species. In both studies, three isolates of M. phaseolina were inoculated, which are kept at the Fungal Culture Collection of UFERSA: MM1531 (GenBank identificatio: MM1531 (GenBank identification: MN136199), ME249 and ME250. Plants received inoculum of the pathogen in pieces of colonized toothpick and were evaluated for the incidence and severity of the disease. Both species showed resistant plants, but with varied frequencies for the accessions. Considering the species, the frequencies observed for C. moschata were higher than those observed for C. maxima. The accessions of C. moschata ABPUN 206 F1, P114-1, P160-2, P11-2, P114-6, P14-02 and P97-1 show different levels of resistance to the Macrophomina phaseolina isolates MM1531, ME-249 and ME-250.Thus, for an efficient selection in a breeding program for the characteristic, the selection strategies adopted must consider each source of resistance in isolationand not each species.

Carotenoid quantification in food can be performed by various techniques, such as spectrophotometry, mass spectrometry, high performance liquid chromatography, gas chromatography, and colorimetry. The objective of this study was to verify the feasibility of indirect selection for assessment of total carotenoids in pumpkin accessions. The experimental design comprised of complete randomized blocks with two replications and three plants per plot. The treatments consisted of 51 Cucurbita moschata Duch accessions from the DCAF/UFERSA Cucurbitaceae germplasm collection and a commercial C. maxima Duch cultivar. After maturation, the fruits were harvested, and colorimetric and total carotenoid contents were evaluated. Considering the effect of accessions as random, variance components were estimated, and the genotypic values were predicted by maximum restricted likelihood (REML) or best linear unbiased prediction (BLUP). Both direct and indirect genetic gains were estimated from a selection intensity of 50%. Pulp color intensity parameters and h° angle indicated the possibility of indirect selection of accessions with higher total carotenoid contents. The ABO22 accession presented higher total carotenoid content under the evaluation conditions of the experiment.

La cuantificación de los carotenoides en los alimentos se puede realizar mediante diversas técnicas, como la espectrofotometría, la espectrometría de masas, la cromatografía líquida de alto rendimiento, la cromatografía de gases y la colorimetría. El objetivo de este estudio fue verificar la viabilidad de la selección indirecta para evaluar los carotenoides totales en las accesiones de calabaza. El diseño experimental fue bloques completos al azar, con dos repeticiones y tres plantas por parcela. Los tratamientos consistieron en 51 accesiones de Cucurbita moschata Duch de la colección de germoplasma DCAF/UFERSA Cucurbitaceae y un cultivar comercial de C. maxima Duch. Después de la maduración, se cosecharon los frutos y se evaluó el contenido colorimétrico y total de carotenoides. Considerando el efecto de las accesiones como aleatorio, se estimaron los componentes de la varianza y se predijeron los valores genotípicos mediante la máxima verosimilitud restringida (REML) o una mejor predicción lineal e imparcial (BLUP). Las ganancias genéticas directas e indirectas se estimaron con base en una intensidad de selección del 50%. Los parámetros de intensidad de color de la pulpa y el ángulo h° indicaron la posibilidad de selección indirecta de accesiones con un contenido de carotenoides total más alto. La adhesión a ABO22 mostró un mayor contenido de carotenoides totales en las condiciones de evaluación del experimento.

Weed control in the sesame crop (Sesamum indicum L.) is a fundamental practice that ensures high grain yield. Choosing adequate control methods is a crucial step to reduce costs and reach success in weed management. Among these methods, application of chemicals shows high efficiency and low cost for farmers. However, the use of this method in sesame crops is limited because there is a restricted number of herbicides registered for pre- and post-emergence applications. Considering the importance of chemical methods for weed management, the objective of this research was to select herbicides to be applied in pre-emergence that could be used to control weeds in the sesame crop. Two experiments were carried out, one to determine the efficiency and another to determine the selectivity of herbicides applied in pre-emergence. The experiments were performed in a randomized complete block design (CBD) with four replicates. The treatments consisted of seven herbicides, a mixture of herbicides applied in pre-emergence, and two control treatments, one weed-free and one with weeds. Diuron and flumioxazin were found to be selective for pre-emergence. Metribuzin exhibited high toxicity to sesame, but it was effective to control several weed species, and metolachlor did not provoke high phytotoxicity in sesame, but reduced yield.

El control de malezas en el cultivo del sésamo (Sesamum indicum L.) es una práctica fundamental para asegurar la alta productividad de esta oleaginosa. La elección de los métodos de control que serán adoptados son fundamentales para el éxito del manejo de malezas. Entre los métodos que se pueden aplicar, el químico es el más utilizado debido a su eficiencia y bajo costo. Sin embargo, el uso de este método en cultivos de sésamo es limitado debido a la escasez de información sobre la selectividad y eficiencia de herbicidas aplicados en pre-emergencia para este cultivo. El objetivo de este trabajo fue seleccionar herbicidas aplicados en pre-emergencia que pueden ser utilizados para el control de malezas en el cultivo de sésamo. En el año 2017, se realizaron dos experimentos, uno para determinar la eficiencia y otro para determinar la selectividad de herbicidas aplicados en pre-emergencia. Los experimentos fueron conducidos en un diseño estadístico de bloques (DBC) con cuatro repeticiones. Los tratamientos estuvieron constituidos por diez tratamientos (por siete herbicidas y una mezcla de herbicidas aplicados en pre-emergencia) y otros dos tratamientos, desmalezado (libre de malezas) y sin desmalezar (con malezas). Los herbicidas diuron y flumioxazin fueron selectivos para el cultivo de sésamo en pre-emergencia. El herbicida metribuzin causó alta toxicidad a las plantas de sésamo y no controló las malas hierbas. Metalachor no provocó intoxicación del sésamo, pero redujo la productividad del cultivo.

The objective of this study was to evaluate the sustainability and agro-economic viability from two croppings of coriander (C) and two of arugula (A) intercropped with beet (B) as a function of roostertree additions to the soil in different population densities. The experimental design was a randomized complete block, with treatments arranged in a 4 x 4 factorial scheme with four replications. The treatments resulted from the combination of four amounts of roostertree biomass (6, 19, 32 and 45 t ha-1 on dry basis) with four population densities of coriander, beet and arugula (20C-50B-20A%, 30C-50B-30A%, 40C-50B-40 A % and 50C-50B-50A% of the recommended densities in their single crops). The maximum agronomic efficiency of the polyculture of coriander, beet and arugula was obtained with the density of 40C-50B-40A and the amount of 19 t ha-1 roostertree biomass incorporated into the soil. The highest profitability of the polyculture was obtained with the density of 20C-50B-20A (%) and the amount of 45 t ha-1 of this green manure. High agro-economic efficiency can be obtained by cultivating the polyculture of coriander, beet and arugula when well-manageding the factors of production, fertilization with roostertree and population densities.

RESUMEN El objetivo de este estudio fue evaluar la sostenibilidad y la viabilidad agroeconómica de dos cultivos de cilantro (C) y dos de rúcula (A) intercalados con remolacha (B) en función de las cantidades de diferentes densidades de población de roostertree añadidas al suelo. El diseño experimental fue un bloque completo aleatorizado, con tratamientos dispuestos en un esquema factorial de 4 x 4 con cuatro repeticiones. Los tratamientos fueron el resultado de la combinación de cuatro cantidades de biomasa de roostertree (6, 19, 32 y 45 t ha-1 en base seca) con cuatro densidades de población de cilantro, remolacha y rúcula (20C-50B-20A%, 30C-50B-30A%, 40C-50B-40 A % y 50C-50B-50A% de las densidades recomendadas en sus cultivos individuales). La máxima eficiencia agronómica del policultivo de cilantro, remolacha y rúcula se obtuvo con la densidad de 40C-50B-40A en la cantidad de 19 t ha-1 de biomasa de roostertree incorporada al suelo. La mayor rentabilidad del policultivo se alcanzó a la densidad de 20C-50B-20 (%) y la cantidad de 45 t ha-1 de este abono verde. Se puede obtener una alta eficiencia agro-económica cultivando el policultivo de cilantro, remolacha y rúcula cuando se manejan bien los factores de producción, la fertilización con roostertree y las densidades.