Passiflora cincinnata Mast. has become more popular in the market because the unusual flavor of its fruits and natural beauty of its flowers, and has great potential for breeding programs of Passiflora edulis f. flavicarpa, because its resistance to diseases and drought. The objective of this work was to evaluate seven wild passion fruit (P. cincinnata) accessions, using morphological and agronomic descriptors and molecular markers type ISSR, to identify their morphoagronomic and genetic variabilities and potential for use in breeding programs. A randomized block experimental design was used with five replications and two plants per plot. Thirteen qualitative and twenty-one quantitative, vegetative and floral characteristics were used for morphoagronomic characterization. Twelve ISSR primers were evaluated for molecular characterization. Among the qualitative characteristics, only the color variations were significantly different between the accessions. According to the mean squares of the quantitative characteristics evaluated, obtained from analysis of variance, the means of accessions showed significant differences (p<0.01) for all characteristics. The IAL (internode average length) was the morphological descriptor that most contributed to diversity, with 43.12%, followed by DH5 (stem diameter at 5 cm height) and SW (sepal width). The average genetic similarity found was 68%. Despite the low genetic variability found among accessions, the primers UBC-887 and UBC-841 stood out with high percentage of polymorphism with 14 and 11 polymorphic fragments, respectively, and higher values of polymorphism information content (PIC), resolving power (RP) and marker index (MI), denoting suitability for use in diversity studies of P. cincinnata. Low variability was found among accessions evaluated.

ABSTRACT Passiflora cincinnata Mast. has become more popular in the market because the unusual flavor of its fruits and natural beauty of its flowers, and has great potential for breeding programs of Passiflora edulis f. flavicarpa, because its resistance to diseases and drought. The objective of this work was to evaluate seven wild passion fruit (P. cincinnata) accessions, using morphological and agronomic descriptors and molecular markers type ISSR, to identify their morphoagronomic and genetic variabilities and potential for use in breeding programs. A randomized block experimental design was used with five replications and two plants per plot. Thirteen qualitative and twenty-one quantitative, vegetative and floral characteristics were used for morphoagronomic characterization. Twelve ISSR primers were evaluated for molecular characterization. Among the qualitative characteristics, only the color variations were significantly different between the accessions. According to the mean squares of the quantitative characteristics evaluated, obtained from analysis of variance, the means of accessions showed significant differences (p<0.01) for all characteristics. The IAL (internode average length) was the morphological descriptor that most contributed to diversity, with 43.12%, followed by DH5 (stem diameter at 5 cm height) and SW (sepal width). The average genetic similarity found was 68%. Despite the low genetic variability found among accessions, the primers UBC-887 and UBC-841 stood out with high percentage of polymorphism with 14 and 11 polymorphic fragments, respectively, and higher values of polymorphism information content (PIC), resolving power (RP) and marker index (MI), denoting suitability for use in diversity studies of P. cincinnata. Low variability was found among accessions evaluated. | RESUMO A espécie Passiflora cincinnata Mast. vem se popularizando no mercado pelo sabor incomum dos seus frutos, beleza natural de sua flores e possui grande potencial para a cultura de Passiflora edulis f. flavicarpa, pois apresenta resistência a doenças e déficit hídrico. Este trabalho teve como objetivo avaliar sete acessos de maracujá-do-mato (P. cincinnata) por meio de descritores morfológicos, descritores agronômicos e marcadores moleculares do tipo ISSR visando identificar variabilidade morfoagronômica e genética e o potencial para serem utilizados em programas de melhoramento. O delineamento experimental foi em blocos casualizados, com cinco repetições e duas plantas por parcela. Para caracterização morfoagronômica foram avaliadas 13 características qualitativas e 21 características quantitativas vegetativas e florais. Para caracterização molecular foram testados 12 primers de ISSR. Entre as características qualitativas apenas as variações de coloração apresentaram diferenças marcantes entre os diferentes acessos. De acordo com os quadrados médios obtidos das análises de variância para as características quantitativas avaliadas pode-se ressaltar as diferenças significativas (p<0,01) entre as médias dos acessos para todos os caracteres avaliados. Verificou-se que para os 21 descritores morfológicos avaliados, o que mais contribuiu para a diversidade foi o MI (média internódio) com 43,12%, seguido por DH5 (diâmetro das hastes a 5 centímetros do solo) e LS (largura da sépala). A similaridade genética média encontrada foi 68%. Apesar de ser diagnosticada baixa variabilidade genética entre os acessos avaliados, os primers UBC-887 e UBC-841 se destacaram com alto percentual de polimorfismo, com 14 e 11 fragmentos polimórficos respectivamente e valores altos para conteúdo da informação de polimorfismo (PIC), poder de resolução do primer (RP) e índice do marcador (MI) dos primers, demonstrando aptidão para serem utilizados em pesquisas de diversidade em P. cincinnata. Foi diagnosticada baixa variabilidade entre os acessos avaliados.

The objective of this work was to evaluate the effect of applying mixtures of chemical ripeners on the technological quality and agricultural productivity of sugarcane. The experimental design consisted of randomized blocks arranged in split- split-plots with four blocks, the main plots being constituted by sugarcane varieties SP803280 and SP801842. The subplots consisted of the application of the following products with their respective mixtures: control - absence of ripener; Sulfometrom methyl + glyphosate; ethephon + glyphosate; glyphosate and compounds of organic carboxylic radicals + glyphosate. The sub-subplots were composed of evaluation times: 0; 15 and 30 days after applying the products. Samples from each plot were collected manually and sent to the laboratory for the determination of soluble Brix solids (% broth); Sucrose content in the broth - Pol (% broth); Reducing sugars (RS%); Total reducing sugars (TRS%); Fiber (%); Purity (%); Humidity (%) and Total recoverable sugar TRS (kg t-1). The plots were fully harvested and the stems were taken for weighing and for characteristics determination: Yield per hectare (TCH) and Yield of sugar per hectare (TAH). The SP803280 variety was more responsive to the use of mixtures of chemical ripeners. For the technological characteristics, sulfometurom methyl (0.02 kg ha-1) + glyphosate (0.15 L ha-1) presented the best results from 15 days after application. Mixtures of chemical ripeners did not increase the yields of stalks and sugar per area.

ABSTRACT The objective of this work was to evaluate the effect of applying mixtures of chemical ripeners on the technological quality and agricultural productivity of sugarcane. The experimental design consisted of randomized blocks arranged in split- split-plots with four blocks, the main plots being constituted by sugarcane varieties SP803280 and SP801842. The subplots consisted of the application of the following products with their respective mixtures: control - absence of ripener; Sulfometrom methyl + glyphosate; ethephon + glyphosate; glyphosate and compounds of organic carboxylic radicals + glyphosate. The sub-subplots were composed of evaluation times: 0; 15 and 30 days after applying the products. Samples from each plot were collected manually and sent to the laboratory for the determination of soluble Brix solids (% broth); Sucrose content in the broth - Pol (% broth); Reducing sugars (RS%); Total reducing sugars (TRS%); Fiber (%); Purity (%); Humidity (%) and Total recoverable sugar TRS (kg t-1). The plots were fully harvested and the stems were taken for weighing and for characteristics determination: Yield per hectare (TCH) and Yield of sugar per hectare (TAH). The SP803280 variety was more responsive to the use of mixtures of chemical ripeners. For the technological characteristics, sulfometurom methyl (0.02 kg ha-1) + glyphosate (0.15 L ha-1) presented the best results from 15 days after application. Mixtures of chemical ripeners did not increase the yields of stalks and sugar per area. | RESUMO O objetivo deste trabalho foi avaliar a aplicação das misturas de maturadores químicos na qualidade tecnológica e produtividade agrícola da cana-de-açúcar . Foi utilizado o delineamento experimental em blocos casualizados arranjados em parcelas sub-subdivididas com 4 blocos, sendo as parcelas principais constituídas pelas variedades de cana-de-açúcar: SP803280 e SP801842. As subparcelas consistiram da aplicação dos seguintes produtos com suas respectivas misturas: controle - ausência de maturador; sulfometurom metil + glifosato; etefon + glifosato; glifosato e compostos de radicais carboxílicos orgânicos + glifosato. As sub-subparcelas foram constituídas de épocas de avaliação: 0; 15 e 30 dias após as aplicações dos produtos. As amostras de cada parcela foram colhidas manualmente e encaminhadas ao laboratório para determinação dos sólidos solúveis Brix (% caldo); teor de sacarose no caldo - Pol (% caldo); Açúcares redutores (AR%); Açúcares redutores totais (ART%); Fibra (%); Pureza (%); Umidade (%) e Açúcar total recuperável ATR (kg t-1). As parcelas foram totalmente colhidas e os colmos despontados para pesagem e para a determinação das características: Rendimento de colmos por hectare (TCH) e Rendimento de açúcar por hectare (TAH). A variedade SP803280 destacou-se como mais responsiva ao uso das misturas de maturadores químicos. Para as características tecnológicas, a mistura sulfometurom metil (0,02 kg ha-1) + glifosato (0,15 L ha-1) apresentou os melhores resultados a partir dos 15 dias após a sua aplicação. As misturas de maturadores químicos não proporcionaram aumentos de produtividade de colmos e açúcar por área.

The objective of this work was to evaluate the agronomic performance and estimate the genetic divergence of 18 cotton genotypes grown in the main season (sowed in December, 2012) and off season (sowed in January, 2013), considering their agronomic characteristics and resistance to Ramularia leaf spot. A randomized block experimental design was used, with five replications. The characteristics evaluated were plant height, first branch height, position of first fruiting branch, height of first fruiting branch, length between nodes, number of nodes, average number of bolls per plant, average boll weight, area under the disease progress curve (AUDPC) related to the Ramularia leaf spot severity, weight of 100 - seed from the plant middle third, fiber percentage, average production per plant, yield and cotton fiber quality. The results were subjected to individual and joint analysis of variance and the genetic divergence was estimated according to multivariate procedures (Mahalanobis' generalized distance and Tocher's optimization method). The dissimilarity matrices were summed to estimate the genetic divergence, considering both growing periods. Genetic variability was found among the genotypes evaluated, in both the main season and off season. The characteristic that most contributed to the genetic divergence in the main season was the production per plant and, in the off season, was the fiber percentage. According to the results of the present work, the crosses between the genotypes BRS - 335 and FMT - 707; FM - 910 and FMT - 707; and IMA - 08 - 12427 and FMT - 707 are recommended.

ABSTRACT The objective of this work was to evaluate the agronomic performance and estimate the genetic divergence of 18 cotton genotypes grown in the main season (sowed in December, 2012) and off season (sowed in January, 2013), considering their agronomic characteristics and resistance to Ramularia leaf spot. A randomized block experimental design was used, with five replications. The characteristics evaluated were plant height, first branch height, position of first fruiting branch, height of first fruiting branch, length between nodes, number of nodes, average number of bolls per plant, average boll weight, area under the disease progress curve (AUDPC) related to the Ramularia leaf spot severity, weight of 100-seed from the plant middle third, fiber percentage, average production per plant, yield and cotton fiber quality. The results were subjected to individual and joint analysis of variance and the genetic divergence was estimated according to multivariate procedures (Mahalanobis' generalized distance and Tocher's optimization method). The dissimilarity matrices were summed to estimate the genetic divergence, considering both growing periods. Genetic variability was found among the genotypes evaluated, in both the main season and off season. The characteristic that most contributed to the genetic divergence in the main season was the production per plant and, in the off season, was the fiber percentage. According to the results of the present work, the crosses between the genotypes BRS-335 and FMT-707; FM-910 and FMT-707; and IMA-08-12427 and FMT-707 are recommended. | RESUMO O objetivo deste trabalho foi avaliar o comportamento agronômico e estimar a divergência genética entre 18 genótipos de algodeiro, com base em características agronômicas e de resistência à mancha de ramulária. O delineamento experimental foi em blocos ao acaso com cinco repetições, em duas épocas de plantio, sendo em safra (dezembro de 2012) e safrinha (janeiro de 2013). As características avaliadas foram: altura da planta, altura do primeiro ramo, posição do primeiro ramo frutífero, altura do primeiro ramo frutífero em centímetros, comprimento entre nós, número de nós, número médio de capulhos por planta, peso médio por capulho, área abaixo da curva de progresso da severidade da mancha de ramulária (AACPS), peso de cem sementes no terço médio, porcentagem de fibra, produção média por planta, produtividade e as caracteristicas tecnológicas da fibra do algodão.Foi realizada a análise de variância individual e conjunta das características avaliadas e estimada a divergência genética com base nos procedimentos multivariados de distância generalizada de Mahalanobis e o método de agrupamento de otimização de Tocher. Para estimar a divergência genética considerando as duas safras, as matrizes de dissimilaridade foram somadas. Houve variabilidade genética entre os genótipos testados, tanto em condições de safra como de safrinha. As características que mais contribuíram para a divergência genética foram a produção por planta na safra e a porcentagem de fibra na safrinha. Com os resultados deste trabalho sugere-se cruzamentos entre os genótipos BRS 335 e FMT 707, FM 910 e FMT 707, IMA 08-12427 e FMT 707.

The effect of organic fertilization with cattle manure on fertility properties of soils with different clay contents was evaluated; as well as the influence of cattle manure fertilization on the production of lettuce, and on subsequent arugula and common chicory grown in these soils. The experiment with pot plants was arranged in randomized blocks and analyzed in a 3x6 factorial design with four replications. The treatments consisted of three soil types with different clay contents (166; 362; 565 g kg-1) and six cattle manure rates (0; 10; 20; 40; 80, and 160 t ha-1). Batches of each soil were manured, limed, filled in pots, moistened, and incubated for 30 days. Then, mineral base fertilization was applied and one lettuce seedling per each pot was grown. After lettuce harvest, the residual effect of organic fertilization was assessed in two subsequent crops, first arugula and then common chicory. The application of up to 160 t ha-1 cattle manure reduces soil acidity and increases nutrient contents, particularly of P, K and Zn, in soils with 165 to 565 g kg-1 clay content. Fertilization with cattle manure at rates of up to 160 t ha-1 increases electrical conductivity of soils, without affecting growth and yield of the leafy vegetables. Cattle manuring increases the yield of lettuce, as well as of arugula and common chicory grown afterwards.

RESUMO O presente trabalho teve como objetivos avaliar o efeito da adubação com esterco bovino em atributos de fertilidade de solos com diferentes teores de argila e, verificar a influência da adubação com esterco bovino na produção de alface americana, e da rúcula e almeirão, cultivados de forma sucessiva a alface. O experimento foi realizado em vasos, em delineamento em blocos ao acaso, com os tratamentos arranjados em esquema fatorial 3x6 com quatro repetições. Os tratamentos foram constituídos por três solos com diferentes teores de argila (166; 362; 565 g kg-1) e seis doses de esterco bovino (0; 10; 20; 40; 80 e 160 t ha-1). Porções de cada solo receberam esterco bovino e calcário, foram transferidas para vasos, umedecidas e incubadas por 30 dias. A seguir, efetuou-se adubação mineral de plantio e cada vaso recebeu uma muda de alface. Após a colheita da alface, para avaliar o efeito residual da adubação orgânica foram realizados dois cultivos sucessivos, um de rúcula e outro de almeirão. A aplicação de até 160 t ha-1 de esterco bovino diminui a acidez e, aumenta os teores de nutrientes, particularmente P, K e Zn em solos com teores de argila de 165 a 565 g kg-1. A adubação com esterco bovino em doses de até 160 t ha-1 aumenta a condutividade elétrica dos solos, e esse acréscimo não prejudica o crescimento e a produção de hortaliças folhosas. A adubação com esterco bovino aumenta a produção de alface, como também a de rúcula e almeirão, cultivados de forma sucessiva. | ABSTRACT The effect of organic fertilization with cattle manure on fertility properties of soils with different clay contents was evaluated; as well as the influence of cattle manure fertilization on the production of lettuce, and on subsequent arugula and common chicory grown in these soils. The experiment with pot plants was arranged in randomized blocks and analyzed in a 3x6 factorial design with four replications. The treatments consisted of three soil types with different clay contents (166; 362; 565 g kg-1) and six cattle manure rates (0; 10; 20; 40; 80, and 160 t ha-1). Batches of each soil were manured, limed, filled in pots, moistened, and incubated for 30 days. Then, mineral base fertilization was applied and one lettuce seedling per each pot was grown. After lettuce harvest, the residual effect of organic fertilization was assessed in two subsequent crops, first arugula and then common chicory. The application of up to 160 t ha-1 cattle manure reduces soil acidity and increases nutrient contents, particularly of P, K and Zn, in soils with 165 to 565 g kg-1 clay content. Fertilization with cattle manure at rates of up to 160 t ha-1 increases electrical conductivity of soils, without affecting growth and yield of the leafy vegetables. Cattle manuring increases the yield of lettuce, as well as of arugula and common chicory grown afterwards.

Forage cactus species may belong to different genera (such as Opuntia and Nopalea), which can result in different water dynamics at the biosphere-atmosphere interface. The objective of this study was to analyze the water balance in soil cultivated with forage cactus clones under different conditions of soil water availability in the Brazilian semi-arid. The experiment was conducted in the municipality of Serra Talhada, State of Pernambuco. The crop was subjected to nine treatments arranged in a randomized complete block design with three replications in a factorial arrangement of 3x3. The plots were composed of three water availability conditions, with the application of a water depth of 7.5 mm at intervals of 7, 14, and 28 days, and the subplots consisted of three forage cactus clones (IPA Sertânia, Miúda, and Orelha de Elefante Mexicana). The soil water balance (SWB) method was applied, and the ET/ETo ratio was estimated (ET is the actual crop evapotranspiration, and ETo is the reference evapotranspiration) at intervals of 14 days; the results were represented in nine periods of 28 days. There was a difference between SWB components along the cycle and between irrigation conditions (p < 0.05). Nevertheless, ET and rainfall were the most important components in SWB when irrigation was performed. There was no difference in water consumption between forage cactus clones belonging to different genera, resulting in an average of 1.50 mm day-1. The ET/ETo ratio had low magnitude (0.29 ± 0.12), indicating that the ET was more dependent on the water regime than on the atmospheric demand.

ABSTRACT Forage cactus species may belong to different genera (such as Opuntia and Nopalea), which can result in different water dynamics at the biosphere-atmosphere interface. The objective of this study was to analyze the water balance in soil cultivated with forage cactus clones under different conditions of soil water availability in the Brazilian semi-arid. The experiment was conducted in the municipality of Serra Talhada, State of Pernambuco. The crop was subjected to nine treatments arranged in a randomized complete block design with three replications in a factorial arrangement of 3x3. The plots were composed of three water availability conditions, with the application of a water depth of 7.5 mm at intervals of 7, 14, and 28 days, and the subplots consisted of three forage cactus clones (IPA Sertânia, Miúda, and Orelha de Elefante Mexicana). The soil water balance (SWB) method was applied, and the ET/ETo ratio was estimated (ET is the actual crop evapotranspiration, and ETo is the reference evapotranspiration) at intervals of 14 days; the results were represented in nine periods of 28 days. There was a difference between SWB components along the cycle and between irrigation conditions (p < 0.05). Nevertheless, ET and rainfall were the most important components in SWB when irrigation was performed. There was no difference in water consumption between forage cactus clones belonging to different genera, resulting in an average of 1.50 mm day-1. The ET/ETo ratio had low magnitude (0.29 ± 0.12), indicating that the ET was more dependent on the water regime than on the atmospheric demand. | RESUMO A palma é uma espécie pertencente aos gêneros Nopalea e Opuntia, o que pode resultar em dinâmicas de água diferentes na interface biosfera-atmosfera. Assim, objetivou-se analisar o balanço de água no solo cultivado com clones de palma forrageira em diferentes condições de disponibilidade hídrica no Semiárido brasileiro. O experimento foi conduzido em Serra Talhada, PE. A cultura foi submetida a nove tratamentos, dispostos em delineamento em blocos ao acaso, com três repetições, em arranjo fatorial 3x3. As parcelas foram constituídas por três condições de disponibilidade hídrica com a aplicação de uma lâmina de 7,5 mm em intervalos 7; 14 e 28 dias, e as subparcelas por três clones de palma (IPA Sertânia, Miúda e Orelha de Elefante Mexicana). O método do balanço de água no solo (BAS) foi aplicado e a razão ET/ETo estimada (sendo, ET a evapotranspiração real da cultura e ETo a evapotranspiração de referência), em intervalos de 14 dias, e os resultados foram representados em nove períodos de 28 dias. Houve diferença dos componentes do BAS ao longo do ciclo e entre as condições de irrigação (p < 0,05). Embora sob irrigação, a ET e a precipitação foram os componentes mais importantes no BAS. Não houve diferença no consumo de água entre os clones, ainda que pertencentes a diferentes gêneros, resultando média de 1,50 mm dia-1. A razão ET/ETo possuiu baixa magnitude (0,29±0,12), indicando que a ET foi mais dependente do regime hídrico do que da demanda atmosférica.

The objective of this study was to evaluate the agro-economic efficiency of the intercropping of carrot with cowpea-vegetable under different spatial arrangements and population densities in the semi-arid conditions of the Brazilian Northeast. The study was conducted at the "Rafael Fernandes" Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA) during the period July 2013 to February 2014. The experimental design was of randomized complete blocks with four replications and treatments arranged in a 3 × 4 factorial scheme, where the first factor consisted of spatial arrangements (2:2; 3:3 and 4:4) and the second factor by population densities of cowpea-vegetables (100, 80, 60 and 40% of the recommended population in sole crop RPSC). All treatments were fertilized with roostertree (Calotropis procera Ait. R.Br.), which is a spontaneous species of the Caatinga biome. The indices of agronomic efficiency of the intercropping systems assessed were: land equivalent ratio, productive efficiency index and score of the canonical variable. The following economic indicators were also evaluated: gross income, net income, rate of return and profit margin. The agro-economic efficiency of the intercropping system of carrot with cowpea- vegetable was influenced by the spatial arrangements, with the 2:2 arrangements standing out from the others. The greatest agro-economic efficiency of the intercropping of carrot with cowpea-vegetable was obtained in the population density of 100% of the RPSC when the value of the productive efficiency index was 0.75.

RESUMO O objetivo deste estudo foi avaliar a eficiência agroeconômica do consórcio de cenoura com caupi-hortaliça sob diferentes arranjos espaciais e densidades populacionais nas condições semiáridas do Nordeste brasileiro. O estudo foi realizado na Fazenda Experimental “Rafael Fernandes” da Universidade Federal Rural do Semi-Árido (UFERSA) no período de julho 2013 a fevereiro de 2014. O delineamento experimental adotado foi de blocos completos casualizados com quatro repetições, com os tratamentos arranjados em um esquema fatorial 3 x 4, sendo o primeiro fator constituído pelos arranjos espaciais (2:2; 3:3 e 4:4) e o segundo fator pelas densidades populacionais do caupi-hortaliça (100%, 80%, 60% e 40% da população recomendada no cultivo solteiro - PRCS). Todos os tratamentos foram fertilizados com flor-de-seda (Calotropis procera (Ait.) R.Br.), que é uma espécie espontânea do bioma Caatinga. Os índices de eficiência agronômica dos sistemas consorciados avaliados foram: índice de uso eficiente da terra, índice de eficiência produtiva e escore da variável canônica. Foram também avaliados os seguintes indicadores econômicos: renda bruta, renda líquida, taxa de retorno e índice de lucratividade. A eficiência agroeconômica do sistema consorciado de cenoura com caupi-hortaliça foi influenciada pelos arranjos espaciais, com o arranjo 2:2 sobressaindo-se dos demais. A maior eficiência agroeconômica do consórcio de cenoura com caupi-vegetal foi obtida na densidade populacional de 100% da PRCS quando o valor do índice de eficiência produtiva foi de 0,75. | ABSTRACT The objective of this study was to evaluate the agro-economic efficiency of the intercropping of carrot with cowpea-vegetable under different spatial arrangements and population densities in the semi-arid conditions of the Brazilian Northeast. The study was conducted at the "Rafael Fernandes" Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA) during the period July 2013 to February 2014. The experimental design was of randomized complete blocks with four replications and treatments arranged in a 3 × 4 factorial scheme, where the first factor consisted of spatial arrangements (2:2; 3:3 and 4:4) and the second factor by population densities of cowpea-vegetables (100, 80, 60 and 40% of the recommended population in sole crop [RPSC]). All treatments were fertilized with roostertree (Calotropis procera [Ait.] R.Br.), which is a spontaneous species of the Caatinga biome. The indices of agronomic efficiency of the intercropping systems assessed were: land equivalent ratio, productive efficiency index and score of the canonical variable. The following economic indicators were also evaluated: gross income, net income, rate of return and profit margin. The agro-economic efficiency of the intercropping system of carrot with cowpea- vegetable was influenced by the spatial arrangements, with the 2:2 arrangements standing out from the others. The greatest agro-economic efficiency of the intercropping of carrot with cowpea-vegetable was obtained in the population density of 100% of the RPSC when the value of the productive efficiency index was 0.75.

Stream water quality is dependent on many factors, including the source and quantity of the streamflow and the types of geology and soil along the path of the stream. This study aims to evaluate the origin and the mechanisms controlling the input of ions that effect surface water quality in the sub-basin of the Rio das Cobras, Rio Grande do Norte state, Northeastern Brazil. Thirteen ponds were identified for study: three in the main river and ten in the tributaries between, thus covering the whole area and lithology of the sub-basin. The samples were collected at two different times (late dry and rainy periods) in the hydrological years 2009 and 2010, equating to total of four collection times. We analyzed the spatial and seasonal behavior of water quality in the sub-basin, using Piper diagrams, and analyzed the source of the ions using Guibbs diagram and molar ratios. With respect to ions, we found that water predominate in 82% sodium and 76% bicarbonate water (cations and anions, respectively). The main salinity control mechanism was related to the interaction of the colloidal particles (minerals and organic sediment) with the ions dissolved in water. Based on the analysis of nitrates and nitrites there was no evidence of contamination from anthropogenic sources.

ABSTRACT Stream water quality is dependent on many factors, including the source and quantity of the streamflow and the types of geology and soil along the path of the stream. This study aims to evaluate the origin and the mechanisms controlling the input of ions that effect surface water quality in the sub -basin of the Rio das Cobras, Rio Grande do Norte state, Northeastern Brazil. Thirteen ponds were identified for study: three in the main river and ten in the tributaries between, thus covering the whole area and lithology of the sub -basin. The samples were collected at two different times (late dry and rainy periods) in the hydrological years 2009 and 2010, equating to total of four collection times. We analyzed the spatial and seasonal behavior of water quality in the sub-basin, using Piper diagrams, and analyzed the source of the ions using Guibbs diagram and molar ratios. With respect to ions, we found that water predominate in 82% sodium and 76% bicarbonate water (cations and anions, respectively). The main salinity control mechanism was related to the interaction of the colloidal particles (minerals and organic sediment) with the ions dissolved in water. Based on the analysis of nitrates and nitrites there was no evidence of contamination from anthropogenic sources. | RESUMO A qualidade da água de um rio dependente de vários fatores, incluindo a origem e quantidade de escoamento e a formação geologia dos solos ao longo do fluxo. Objetivou-se avaliar a origem e os mecanismos controladores da entrada dos íons e, consequentemente, da qualidade da água na sub-bacia do rio das Cobras, RN. Foram selecionados 13 açudes, sendo 3 no rio principal e 10 entre os afluentes, abrangendo toda a área e litologias da sub-bacia. As amostras foram coletadas em duas épocas distintas (final dos períodos secos e chuvosos) nos anos hidrológicos de 2009 e 2010, totalizando 4 momentos de coleta. Analisou-se o comportamento espacial e sazonal da qualidade da água na sub-bacia utilizando o diagrama de Piper e a origem dos íons pelo diagrama de Gibbs e razão molar. Constatou-se que em relação aos íons, predominam águas sódicas em 82% e águas bicarbonatadas 76% (cátions e ânions), respectivamente. Os resultados obtidos sugerem que o principal mecanismo controlador da salindiade está relacionado a interação das partículas coloidais (sedimentos orgânicos e minerais) com os íons dissolvidos na água. Também não se observou indícios de contaminação antrópica na área, tendo por base a análise de nitratos e nitritos.

The objective of this work was to assess the pulp resistance, soluble solids and yield of watermelon fruits grown under different irrigation managements (determined by the ISAREG model) and mulches, and their interactions. After a survey carried out on local producers, two experiments were conducted, using a completely randomized block design in split - plot arrangement with four replications, in the Teaching, Research and Extension Unit (UEPE) of the Federal Institute of Ceara (IFCE), Jaguaribe - Apodi Irrigation District (DIJA), State of Ceara, Brazil. The treatments consisted of four irrigation managements in the plots, M1 (100% of the available - water capacity (AWC) of the soil), M2 (80%), M3 (60%) and M4 (average water depth used by local producers) and four mulch types in the sub - plots, without mulching (C0) with rice husk (C1), white plastic (C2) and black plastic (C3) as mulches. The results were subjected to analysis of variance, and significant results were subjected to regression (irrigation managements), average test (mulches) and trend graphs (interaction between the factors). The irrigation management practiced during the watermelon crop cycle by the local producers of the Irrigation District of Jaguaribe - Apodi (DIJA) in the State of Ceara, Brazil, is not appropriated, since they usually apply more water than the highest water depth determined by the ISAREG model (100% of the AWC). The plants grown under irrigation water depth of 365.20 mm (M1) and soils with mulches of rice husk or white plastic had the highest yields and fruits with better quality of soluble solids and pulp resistance.

RESUMO Objetivou-se avaliar a resistência de polpa e os sólidos solúveis dos frutos, e a produtividade da melancieira, sob diferentes proposições de irrigação (geradas pelo ISAREG) e condições de cobertura do solo; e seus efeitos de interação. Após pesquisa de campo junto aos irrigantes foram realizados dois experimentos na UEPE (Unidade de Ensino, Pesquisa e Extensão) do IFCE, no Distrito de irrigação Jaguaribe -Apodi, DIJA, sob delineamento em blocos completos ao acaso, com parcelas subdivididas e quatro repetições. Os tratamentos consistiram da combinação de quatro proposições de irrigação (M1 - manutenção de 100% da capacidade de água disponível no solo (CAD); M2 - 80 %; M3 - 60%; e M4 - lâmina modal dos irrigantes) nas parcelas, e quatro sub-parcelas, compostas por três condições de cobertura no solo (coberturas com casca de arroz, com “mulching” branco e com “mulching” preto, denominadas C1, C2 e C3), e uma sem cobertura, denominada C0. Os resultados foram submetidos à análise de variância e quando significativos, à regressão (lâminas), a teste de médias (coberturas) e a gráficos de tendência (interação entre os fatores). Concluiu-se que os irrigantes não praticam o manejo correto da irrigação, pois aplicam, durante todo o ciclo da melancia, mais água do que a indicação de maior lâmina do ISAREG (100% da CAD). As plantas irrigadas pela lâmina M1 em solo coberto por casca de arroz e “mulching” branco demonstraram melhores características produtivas e de pós-colheita. | ABSTRACT The objective of this work was to assess the pulp resistance, soluble solids and yield of watermelon fruits grown under different irrigation managements (determined by the ISAREG model) and mulches, and their interactions. After a survey carried out on local producers, two experiments were conducted, using a completely randomized block design in split-plot arrangement with four replications, in the Teaching, Research and Extension Unit (UEPE) of the Federal Institute of Ceara (IFCE), Jaguaribe-Apodi Irrigation District (DIJA), State of Ceara, Brazil. The treatments consisted of four irrigation managements in the plots, M1 (100% of the available-water capacity (AWC) of the soil), M2 (80%), M3 (60%) and M4 (average water depth used by local producers) and four mulch types in the sub-plots, without mulching (C0) with rice husk (C1), white plastic (C2) and black plastic (C3) as mulches. The results were subjected to analysis of variance, and significant results were subjected to regression (irrigation managements), average test (mulches) and trend graphs (interaction between the factors). The irrigation management practiced during the watermelon crop cycle by the local producers of the Irrigation District of Jaguaribe-Apodi (DIJA) in the State of Ceara, Brazil, is not appropriated, since they usually apply more water than the highest water depth determined by the ISAREG model (100% of the AWC). The plants grown under irrigation water depth of 365.20 mm (M1) and soils with mulches of rice husk or white plastic had the highest yields and fruits with better quality of soluble solids and pulp resistance.

The present study was conducted with the objective of analyzing the covariance structure and repeatability estimates of the variables related to guava productivity, such as fruit weight (FW), fruit number (FN) and fruit production (FP) of three harvests, in 95 genotypes of a segregating population. The study also aims to choose the most appropriate covariance structure of the observations within the same individual by means of AIC (Akaike's Information Criterion) and SBC (Schwarz's Bayesian Criterion) criteria. A covariance structure between repeated measures could be incorporated into the statistical model, with the self-regression and compound symmetry forms being the most adequate. The values of repeatability coefficients obtained for FW (0.25), FN (0.14), and FP (0.29) were considered low, indicating that the three harvests were not sufficient to select the best individuals with greater accuracy for the study population. For the variables PF and FP, estimates of accuracy around 0.50 could be obtained from five measurements, while for the variable FN more harvests would be necessary. These values indicate that in guava-segregating populations, evaluations in the first harvests are not enough to select more stable genotypes for the variables considered in this study.

RESUMO O presente estudo foi conduzido com o objetivo de analisar estrutura de covariância e estimativas de repetibilidade das variáveis relacionadas à produtividade da goiabeira como massa dos frutos (MF), número de frutos (NF) e produção de frutos (PROD) de três safras, em 95 genótipos de uma população segregante. E por meio dos critérios de AIC (Akaike’s Information Criterion) e SBC (Schwarz’s Bayesian Criterion) escolher a estrutura de covariância mais adequada das observações dentro de um mesmo indivíduo. Foi possível incorporar ao modelo estatístico, uma estrutura de covariância entre medidas repetidas, sendo as formas autorregressiva e simetria composta as mais adequadas. Os valores dos coeficientes de repetibilidade obtidos para PF (0,25), NF (0,14) e PROD (0,29) foram considerados baixos, indicando que para a população em estudo as três safras realizadas não foram suficientes para selecionar os melhores indivíduos com maior acurácia. Para as variáveis PF e PROD, a partir de cinco medições seria possível a obtenção de estimativas de acurácias em torno de 0,50. Enquanto que para a variável NF, observou-se que mais safras seriam necessárias. Estes valores indicam que em populações segregantes de goiabeira, avaliações nas primeiras safras, não são suficientes para seleção de genótipos mais estáveis para as variáveis consideradas neste estudo. | ABSTRACT The present study was conducted with the objective of analyzing the covariance structure and repeatability estimates of the variables related to guava productivity, such as fruit weight (FW), fruit number (FN) and fruit production (FP) of three harvests, in 95 genotypes of a segregating population. The study also aims to choose the most appropriate covariance structure of the observations within the same individual by means of AIC (Akaike's Information Criterion) and SBC (Schwarz's Bayesian Criterion) criteria. A covariance structure between repeated measures could be incorporated into the statistical model, with the self-regression and compound symmetry forms being the most adequate. The values of repeatability coefficients obtained for FW (0.25), FN (0.14), and FP (0.29) were considered low, indicating that the three harvests were not sufficient to select the best individuals with greater accuracy for the study population. For the variables PF and FP, estimates of accuracy around 0.50 could be obtained from five measurements, while for the variable FN more harvests would be necessary. These values indicate that in guava-segregating populations, evaluations in the first harvests are not enough to select more stable genotypes for the variables considered in this study.

The use of nitrogenous fertilizer coated by polymers may reduce losses caused by volatilization, thus exposing this element to plants for a longer period of time. The objective of this work was to evaluate the residual effects of nitrogen in the form of conventional urea and urea coated by polymers in the production components and grain productivity of the first and second corn crops. The experiment was conducted in Selvíria - MS in a clay-type Oxisol during the corn crops of 2011/12 and 2012. The experiment was arranged as a randomized block design with four replications, with a factorial 4 x 4 treatment arrangement as follows: 4 doses of N (0, 40, 80 and 120 kg ha-1) and 4 forms of urea (conventional urea and urea coated by three different polymers). Treatments were applied at the time of corn sowing in the first season (2010/11) and second season (2011). The residual effects of nitrogen fertilization in the corn grown in the first crop season (2011/12) and the second crop season (2012) were then assessed. The polymer -coated urea did not differ compared to the conventional urea.

ABSTRACT The use of nitrogenous fertilizer coated by polymers may reduce losses caused by volatilization, thus exposing this element to plants for a longer period of time. The objective of this work was to evaluate the residual effects of nitrogen in the form of conventional urea and urea coated by polymers in the production components and grain productivity of the first and second corn crops. The experiment was conducted in Selvíria - MS in a clay-type Oxisol during the corn crops of 2011/12 and 2012. The experiment was arranged as a randomized block design with four replications, with a factorial 4 x 4 treatment arrangement as follows: 4 doses of N (0, 40, 80 and 120 kg ha-1) and 4 forms of urea (conventional urea and urea coated by three different polymers). Treatments were applied at the time of corn sowing in the first season (2010/11) and second season (2011). The residual effects of nitrogen fertilization in the corn grown in the first crop season (2011/12) and the second crop season (2012) were then assessed. The polymer -coated urea did not differ compared to the conventional urea. | RESUMO A utilização de fertilizantes nitrogenados revestidos por polímeros pode permitir a redução das perdas por volatilização, disponibilizando assim, esse elemento para as plantas por maior período de tempo. Neste contexto, objetivou-se avaliar o efeito residual de doses de nitrogênio na forma de ureia convencional e ureias revestidas por polímeros, nos componentes de produção e na produtividade da cultura do milho primeira e segunda safra. O experimento foi conduzido em Selvíria - MS, em Latossolo Vermelho distrófico de textura argilosa, em 2011/12 e 2012. O experimento foi disposto em blocos casualizados com quatro repetições, e os tratamentos em um esquema fatorial 4 x 4, sendo: 4 doses de N (0, 40, 80 e 120 kg ha -1) e 4 formas de ureia (ureia convencional e ureias revestidas por 3 diferentes polímeros). Os tratamentos foram aplicados na semeadura do milho na primeira safra (2010/11) e segunda safra (2011), sendo avaliado o efeito residual da adubação nitrogenada no cultivo sucessor de milho na primeira safra (2011/12) e segunda safra (2012). As formas de ureia revestidas por polímeros não diferiram em relação à ureia convencional.