RESUMO A seleção genômica ampla (Genome Wide Selection - GWS) utiliza simultaneamente o efeito de milhares de marcadores cobrindo todo o genoma para predizer o valor genético genômico dos indivíduos no processo de seleção. Os possíveis benefícios de seu uso são a redução do ciclo de melhoramento, propiciando maior ganho por unidade de tempo e diminuição de custos. O sucesso da GWS está atrelado a escolha do método de predição dos efeitos dos marcadores. Assim, neste trabalho, visou-se aplicar as redes neurais artificiais (Artificial Neural Networks - ANNs), com a finalidade de predizer os valores genéticos genômicos (Genomic Breeding Values - GEBVs) baseado na estimação dos efeitos dos marcadores comparados a regressão de cumeeira - melhor preditor não viesado/seleção genômica ampla (Ridge Regression - Best Linear Unbiased Predictor/Genome Wide Selection - RR-BLUP/GWS). Foram efetuadas simulações por meio do software R, fornecendo as correlações referentes às ANNs e a RR-BLUP/GWS. Os métodos de predição foram avaliados utilizando correlações entre o valor fenotípico e valor genotípico com o valor genético genômico predito. Os resultados demonstraram superioridade das ANNs na predição dos GEBVs nos cenários com maior e menor densidade de marcadores, paralelo a níveis mais altos de desequilíbrio de ligação e maior herdabilidade. | ABSTRACT Genome-wide selection (GWS) uses simultaneously the effect of the thousands markers covering the entire genome to predict genomic breeding values for individuals under selection. The possible benefits of GWS are the reduction of the breeding cycle, increase in gains per unit of time, and decrease of costs. However, the success of the GWS is dependent on the choice of the method to predict the effects of markers. Thus, the objective of this work was to predict genomic breeding values (GEBV) through artificial neural networks (ANN), based on the estimation of the effect of the markers, compared to the Ridge Regression-Best Linear Unbiased Predictor/Genome Wide Selection (RR-BLUP/GWS). Simulations were performed by software R to provide correlations concerning ANN and RR-BLUP/GWS. The prediction methods were evaluated using correlations between phenotypic and genotypic values and predicted GEBV. The results showed the superiority of the ANN in predicting GEBV in simulations with higher and lower marker densities, with higher levels of linkage disequilibrium and heritability.

Genome-wide selection (GWS) uses simultaneously the effect of the thousands markers covering the entire genome to predict genomic breeding values for individuals under selection. The possible benefits of GWS are the reduction of the breeding cycle, increase in gains per unit of time, and decrease of costs. However, the success of the GWS is dependent on the choice of the method to predict the effects of markers. Thus, the objective of this work was to predict genomic breeding values (GEBV) through artificial neural networks (ANN), based on the estimation of the effect of the markers, compared to the Ridge Regression-Best Linear Unbiased Predictor/Genome Wide Selection (RR-BLUP/GWS). Simulations were performed by software R to provide correlations concerning ANN and RR-BLUP/GWS. The prediction methods were evaluated using correlations between phenotypic and genotypic values and predicted GEBV. The results showed the superiority of the ANN in predicting GEBV in simulations with higher and lower marker densities, with higher levels of linkage disequilibrium and heritability.

ABSTRACT Potato (Solanum tuberosum L.) is a nutritionally demanding crop, and phosphorus (P) is a nutrient that exerts a large effect on tuber yield. However, as the availability of P is influenced by soil texture, there are doubts about how P supplementation affects the growth and yield of potato plants in different soil textures. Thus, here we aimed to evaluate the effect of P fertilization and soil texture on the nutrition, growth, tuber yield, and P use efficiency (PUE) of potato plants. The experiment was conducted under greenhouse conditions in a randomized block design with a 4×2 factorial scheme and five replications. The treatments were represented by four P rates (10, 50, 100, and 200 mg dm-3 P) and two soil textures (clayey and sandy). The concentrations of P, Ca, and Mg in the leaves were higher in sandy soil, and P rates increased the concentrations of N, P, and Ca in the leaves of potato plants. Phosphorus fertilization increased plant growth, the amount of P accumulated in the shoot, and tuber yield in both soils; this trend was stronger in the potato cultivated in the clayey soil than in the sandy soil. The applied-PUE was not affected by soil texture. In the potato cultivated in the sandy soil, the taken up-PUE was reduced due to the decrease in dry matter production and an increase in P concentration in the organs of the plant with higher P fertilizer rates. | RESUMO A batata (Solanum tuberosum L.) é uma cultura nutricionalmente exigente e o fósforo (P) é um dos nutrientes que exerce grande efeito sobre a produtividade de tubérculos. Porém, como a disponibilidade de P é influenciada pela textura do solo, existem dúvidas de como o fornecimento de P afeta o crescimento e a produtividade das plantas de batata em solos de texturas diferentes. Assim, objetivou-se com esta pesquisa avaliar o efeito da adubação fosfatada e da textura do solo na nutrição, crescimento, produtividade e eficiência de uso (EU) do P das plantas de batata. O experimento foi conduzido em casa de vegetação no delineamento de blocos casualizados em esquema fatorial 4×2, com cinco repetições. Os tratamentos foram representados por quatro doses de P (10, 50, 100 e 200 mg dm-3 P) e duas texturas de solo (argiloso e arenoso). Os teores foliares de P, Ca e Mg foram maiores no solo arenoso e as doses de P aumentaram os teores de N, P e Ca nas folhas. A adubação fosfatada aumentou o crescimento das plantas, a quantidade de P acumulada na parte aérea e a produtividade de tubérculos em ambos os solos, porém, de forma mais expressiva e até maiores doses na batata cultivada no solo argiloso. A EU do P aplicado não foi afetada pela textura do solo. Na batata cultivada no solo arenoso, a EU do P absorvido foi reduzida em função da diminuição na produção de MS e aumento nos teores de P nos órgãos da planta com fornecimento de altas doses de P.

Potato (Solanum tuberosum L.) is a nutritionally demanding crop, and phosphorus (P) is a nutrient that exerts a large effect on tuber yield. However, as the availability of P is influenced by soil texture, there are doubts about how P supplementation affects the growth and yield of potato plants in different soil textures. Thus, here we aimed to evaluate the effect of P fertilization and soil texture on the nutrition, growth, tuber yield, and P use efficiency (PUE) of potato plants. The experiment was conducted under greenhouse conditions in a randomized block design with a 4×2 factorial scheme and five replications. The treatments were represented by four P rates (10, 50, 100, and 200 mg dm-3 P) and two soil textures (clayey and sandy). The concentrations of P, Ca, and Mg in the leaves were higher in sandy soil, and P rates increased the concentrations of N, P, and Ca in the leaves of potato plants. Phosphorus fertilization increased plant growth, the amount of P accumulated in the shoot, and tuber yield in both soils; this trend was stronger in the potato cultivated in the clayey soil than in the sandy soil. The applied-PUE was not affected by soil texture. In the potato cultivated in the sandy soil, the taken up-PUE was reduced due to the decrease in dry matter production and an increase in P concentration in the organs of the plant with higher P fertilizer rates.

ABSTRACT Green manure may lead to physical, chemical, and biological improvements to the soil. However, the information on its use in the Brazilian Northeast is scarce. The aim of this study was to assess the phenological cycle and phytomass productivity of seven legume species. This study was conducted in the second semester of 2015 in a completely randomized design with seven treatments and four replications. Plant height, fresh mass of shoot (FMS), dry mass of shoot (DMS), fresh mass of root (FMR), and dry mass of root (DMR) were determined at 100 days after sowing. Germination, flowering, and pod maturation were also assessed. The highest averages of FMS were observed in Crotalaria breviflora and Crotalaria mucronata, followed by Canavalia ensiformis, whereas the highest averages of DMS were observed in C. breviflora, C. ensiformis, C. mucronata, and Cajanus cajan cv. IAPAR 43. The highest averages of FMR were obtained by C. breviflora and C. mucronata, followed by C. cajan cv. Fava Larga. The species C. mucronata, C. cajan cv. IAPAR 43, and C. breviflora presented the highest averages of DMR. In addition, C. juncea, C. ensiformis, and C. cajan cv. IAPAR 43 were the earlier species regarding flowering, while C. cajan cv. Fava Larga was the later species. C. juncea was the earliest among all studied species regarding pod maturation. The tested legume species obtained promising initial results during the assessment period, being able to meet the expectations of biomass production and contributing to soil sustainability in this region. | RESUMO A adubação verde pode atribuir melhorias físicas, químicas e biológicas aos solos, porém, são escassas as informações de uso no nordeste brasileiro. Objetivou-se avaliar o ciclo fenológico e as produtividades de fitomassa de sete espécies de leguminosas. O trabalho foi conduzido durante o segundo semestre de 2015, em delineamento inteiramente casualizado, com sete tratamentos e quatro repetições. Aos 100 dias após semeadura (DAS) foram determinadas a altura das plantas, massa fresca (MFPA) e seca da parte aérea (MSPA), massa fresca (MFR) e seca da raiz (MSR). Avaliou-se também a germinação, florescimento e maturação das vagens. As maiores médias para MFPA foram obtidas pelas Crotalaria breviflora e Crotalaria mucronata, seguidas da Canavalia ensiformis. As mais produtivas para MSPA foram C. breviflora, C. ensiformis, C. mucronata, e Cajanus cajan Cv IAPAR 43. As maiores médias para MFR foram obtidas pelas C. breviflora e C. mucronata, seguidas do C. cajan Cv Fava Larga. A C. mucronata, C. cajan Cv IAPAR 43 e C. breviflora foram as espécies que obtiveram as maiores médias de MSR. A Crotalaria juncea, C. ensiformis e C. cajan Cv IAPAR 43 foram as espécies mais precoces em relação à floração, enquanto que C. cajan Cv Fava Larga foi a espécie mais tardia. C. juncea foi a mais precoce, entre todas as espécies estudadas, para a variável maturação das vagens. As espécies de leguminosas testadas obtiveram, durante o período de avaliação, resultados iniciais promissores, podendo atender as expectativas de produção de biomassa, além de contribuir para a sustentabilidade dos solos desta região.

Green manure may lead to physical, chemical, and biological improvements to the soil. However, the information on its use in the Brazilian Northeast is scarce. The aim of this study was to assess the phenological cycle and phytomass productivity of seven legume species. This study was conducted in the second semester of 2015 in a completely randomized design with seven treatments and four replications. Plant height, fresh mass of shoot (FMS), dry mass of shoot (DMS), fresh mass of root (FMR), and dry mass of root (DMR) were determined at 100 days after sowing. Germination, flowering, and pod maturation were also assessed. The highest averages of FMS were observed in Crotalaria breviflora and Crotalaria mucronata, followed by Canavalia ensiformis, whereas the highest averages of DMS were observed in C. breviflora, C. ensiformis, C. mucronata, and Cajanus cajan cv. IAPAR 43. The highest averages of FMR were obtained by C. breviflora and C. mucronata, followed by C. cajan cv. Fava Larga. The species C. mucronata, C. cajan cv. IAPAR 43, and C. breviflora presented the highest averages of DMR. In addition, C. juncea, C. ensiformis, and C. cajan cv. IAPAR 43 were the earlier species regarding flowering, while C. cajan cv. Fava Larga was the later species. C. juncea was the earliest among all studied species regarding pod maturation. The tested legume species obtained promising initial results during the assessment period, being able to meet the expectations of biomass production and contributing to soil sustainability in this region.

ABSTRACT Vetiver grass is a member of the grass family Poaceae. Its fast development is probably due to the interaction with native microbiota, whose influence has not been studied yet. The objective of this work was to evaluate the colonization and development of the vetiver grass (Chrysopogon zizanioides (L.) Roberty) inoculated with arbuscular mycorrhizal fungi and dark septate endophytic fungi. The experimental design was a completely randomized design with six treatments (control, without mycorrhizal fungi, native inoculants, UFLA05 - Gigaspora albida, UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum, and UFLA401 - Acaulospora morrowiae), with three replicates each. Vetiver grass tillers as well as the native microbial inoculum were obtained from the Lower São Francisco river experimental area, located in Sergipe state, Northeastern Brazil. There was a negative interaction between all tested UFLAs mycorrhizal isolates and the native microbiota (mycorrhizal and endophytic fungi) in the treatments, especially when taking into consideration plant height and volume of roots. The effects of inoculation with UFLA isolates may have been influenced by the presence of the native mycorrhizal fungi and the dark septate endophytic fungi. Vetiver grass was responsive to the native inoculant. The mycorrhizal colonization of the vetiver grass was vesicular, but the formation of the arbuscules can be influenced by the interaction between the fungus, plant, and the environment. | RESUMO O capim vetiver é uma espécie da família poácea que apresenta rápido desenvolvimento, provavelmente decorrente da interação com a microbiota nativa, cuja influência ainda não foi estudada. O objetivo deste trabalho foi avaliar a colonização e o desenvolvimento do capim vetiver inoculado com fungos micorrízicos arbusculares e fungos endofíticos "dark septate". O delineamento experimental utilizado foi inteiramente casualizado composto por seis tratamentos (controle sem fungo micorrízico; inoculante microbiano nativo; UFLA05 - Gigaspora albida, UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum e UFLA401 - Acaulospora morrowiae), com três repetições. Os perfilhos de capim vetiver, assim como o inóculo microbiano nativo foram obtidos na área experimental do Baixo São Francisco, localizado no Estado de Sergipe, Nordeste do Brasil. O efeito da inoculação dos isolados UFLAs pode ter sido influenciado pela presença da micorriza nativa e pelos fungos endofíticos "dark septate". Houve uma interação negativa entre todos isolados UFLAs testados e a microbiota nativa (micorriza e endofítico), nos tratamentos, principalmente quando se considera a altura da planta e o volume de raízes. O capim vetiver foi responsivo ao inoculante microbiano nativo. A colonização micorrízica do capim vetiver foi vesicular, mas a formação dos arbúsculos pode ser influenciada pela interação fungo, planta e ambiente.

Vetiver grass is a member of the grass family Poaceae. Its fast development is probably due to the interaction with native microbiota, whose influence has not been studied yet. The objective of this work was to evaluate the colonization and development of the vetiver grass (Chrysopogon zizanioides (L.) Roberty) inoculated with arbuscular mycorrhizal fungi and dark septate endophytic fungi. The experimental design was a completely randomized design with six treatments (control, without mycorrhizal fungi, native inoculants, UFLA05 - Gigaspora albida, UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum, and UFLA401 - Acaulospora morrowiae), with three replicates each. Vetiver grass tillers as well as the native microbial inoculum were obtained from the Lower São Francisco river experimental area, located in Sergipe state, Northeastern Brazil. There was a negative interaction between all tested UFLAs mycorrhizal isolates and the native microbiota (mycorrhizal and endophytic fungi) in the treatments, especially when taking into consideration plant height and volume of roots. The effects of inoculation with UFLA isolates may have been influenced by the presence of the native mycorrhizal fungi and the dark septate endophytic fungi. Vetiver grass was responsive to the native inoculant. The mycorrhizal colonization of the vetiver grass was vesicular, but the formation of the arbuscules can be influenced by the interaction between the fungus, plant, and the environment.

RESUMO A irrigação com água salina é uma necessidade mundial e o excesso de sais da água ou do solo, causa inibição no crescimento e no rendimento da grande maioria das plantas cultivadas. Nesse contexto, os fertilizantes nitrogenados podem constituir alternativa para a mitigação dos efeitos dos sais sobre as plantas. Com isso, objetivou-se avaliar o acúmulo de biomassa e o índice de pigmentos clorofiláticos em mudas de jaqueira irrigadas com água de salinidades crescentes no solo com fontes de nitrogênio. Os tratamentos foram distribuídos em blocos casualizados com quatro repetições e com três plantas por parcela, arranjados em fatorial 5 × 3, relativo aos níveis de condutividade elétrica da água de irrigação de 0,3; 1,0; 2,0; 3,0 e 4,0 dS m-1, no solo sem nitrogênio, com sulfato de amônio e com ureia aplicados parceladamente aos 60 e 75 dias após a semeadura. O aumento da salinidade da água elevou a salinidade do solo, a qual foi intensificada pela dose de 150 mg de N, principalmente quando aplicada na forma de sulfato de amônio, ao ponto de inibir a formação de massa da matéria seca e os teores de clorofila em mudas de jaqueira. As maiores reduções no índice de clorofila a e b foram nas mudas de jaqueira irrigadas com água de 4,0 dS m-1 no solo sem adubação nitrogenada. A ureia é a fonte nitrogenada mais indicada para produção de mudas em condições de elevada salinidade. | ABSTRACT Irrigation with saline water is a worldwide necessity an excess of salts in water or in soil causes growth inhibition, and negatively affects the productivity of many crops. Application of nitrogen fertilizers may be a way of mitigating the effects of salts on plants. The aim of this study was to evaluate the accumulation of biomass and the chlorophyll pigment content in jackfruit seedlings irrigated with water of increasing salinity level in soil with nitrogen sources. The treatments were distributed in randomized blocks with four replicates and three plants per plot, arranged in a 5 × 3 factorial scheme, related to electrical conductivity levels of the irrigation water of 0.3, 1.0, 2.0, 3.0 and 4.0 dS m-1, in soil without nitrogen, with ammonium sulfate and with urea, in a split application 60 and 75 days after sowing. An increase in the salinity of the water increased the salinity levels of soil, which was intensified by a dose of 150 mg of N, mainly when applied in the form of ammonium sulfate, inhibiting dry matter production and chlorophyll content in jackfruit seedlings. The greatest reductions in chlorophyll a and b content occurred in jackfruit seedlings irrigated with water of 4.0 dS m-1 conductivity in the soil without nitrogen fertilization. Urea is the most suitable nitrogen source for the production of seedlings under conditions of high salinity.

Irrigation with saline water is a worldwide necessity an excess of salts in water or in soil causes growth inhibition, and negatively affects the productivity of many crops. Application of nitrogen fertilizers may be a way of mitigating the effects of salts on plants. The aim of this study was to evaluate the accumulation of biomass and the chlorophyll pigment content in jackfruit seedlings irrigated with water of increasing salinity level in soil with nitrogen sources. The treatments were distributed in randomized blocks with four replicates and three plants per plot, arranged in a 5 × 3 factorial scheme, related to electrical conductivity levels of the irrigation water of 0.3, 1.0, 2.0, 3.0 and 4.0 dS m-1, in soil without nitrogen, with ammonium sulfate and with urea, in a split application 60 and 75 days after sowing. An increase in the salinity of the water increased the salinity levels of soil, which was intensified by a dose of 150 mg of N, mainly when applied in the form of ammonium sulfate, inhibiting dry matter production and chlorophyll content in jackfruit seedlings. The greatest reductions in chlorophyll a and b content occurred in jackfruit seedlings irrigated with water of 4.0 dS m-1 conductivity in the soil without nitrogen fertilization. Urea is the most suitable nitrogen source for the production of seedlings under conditions of high salinity.

ABSTRACT The accelerated aging test consists of evaluating the vigor of the seeds under conditions of high temperature and humidity, with the purpose of identifying the physiological quality of lots with similar germination. The objective of this study was to evaluate the efficiency of the accelerated aging test for classifying seed lots of P. moniliformis at different levels of vigor. Initially, the seed lots were assessed by means of seedling emergence, life velocity index, shoot length and root length, total dry mass of seedlings and determination of water content, before and after each period of aging. The experimental design for the whole world was based on a 3 × 4 factorial scheme (three seed lots and four periods of 24, 48, 72 and 96 h duration), with separate evaluations at temperatures of 38 °C and 41 °C. The accelerated aging test conducted at a temperature of 41 °C for 24 h was a more suitable combination for separating batches of P. moniliformis according to different levels of vigour, and made it possible to obtain results similar to the classification of lots in relation to the initial quality. | RESUMO O teste de envelhecimento acelerado consiste em avaliar o vigor das sementes em condições de elevada temperatura e umidade, com a finalidade de identificar diferenças na qualidade fisiológica de lotes com germinação semelhante. Dessa forma, objetivou-se avaliar a eficiência do teste de envelhecimento acelerado para classificar os lotes de sementes de P. moniliformis em diferentes níveis de vigor. Inicialmente os lotes de sementes foram avaliados por meio da emergência de plântulas, índice de velocidade de emergência, comprimento da parte aérea e da raiz, além da massa seca total de plântulas, além da determinação do grau de umidade, antes e após cada período de envelhecimento das sementes. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 3 x 4 (três lotes de sementes e quatro períodos de 24, 48, 72 e 96 horas), e avaliado separadamente nas temperaturas de 38 e 41 °C. O teste de envelhecimento acelerado conduzido sob a temperatura de 41 °C durante 24 horas é a combinação mais adequada para separar os lotes de P. moniliformis em diferentes níveis de vigor, pois possibilitou a obtenção de resultados semelhantes à classificação dos lotes em relação à qualidade inicial.

The accelerated aging test consists of evaluating the vigor of the seeds under conditions of high temperature and humidity, with the purpose of identifying the physiological quality of lots with similar germination. The objective of this study was to evaluate the efficiency of the accelerated aging test for classifying seed lots of P. moniliformis at different levels of vigor. Initially, the seed lots were assessed by means of seedling emergence, life velocity index, shoot length and root length, total dry mass of seedlings and determination of water content, before and after each period of aging. The experimental design for the whole world was based on a 3 × 4 factorial scheme (three seed lots and four periods of 24, 48, 72 and 96 h duration), with separate evaluations at temperatures of 38 °C and 41 °C. The accelerated aging test conducted at a temperature of 41 °C for 24 h was a more suitable combination for separating batches of P. moniliformis according to different levels of vigour, and made it possible to obtain results similar to the classification of lots in relation to the initial quality.

RESUMO O estudo das propriedades físicas e químicas do solo é um procedimento de custo e tempo relativamente elevado. Na busca de alternativas para predizer esses atributos a partir de um número menor de amostras do solo, o uso de Redes Neurais Artificiais (RNA) tem sido apontado como uma técnica computacional com grande capacidade de resolver problemas por meio da experiência, e possuem a capacidade de aquisição e posterior aplicação deste conhecimento. Esse trabalho teve por objetivo utilizar a RNA para estimar os atributos físicos e químicos de solo. Os dados utilizados foram provenientes da análise física e química de solo, coletados em 120 pontos amostrais, os quais foram submetidos à análise descritiva, análise geoestatística, treinamento e análise das RNAs. Na análise geoestatística, para cada atributo do solo, foi verificado o modelo de semivariograma que apresentou melhor ajuste ao modelo experimental, e como método de interpolação foi usada técnica da krigagem ordinária. As RNAs foram treinadas, selecionadas considerando a assertividade no mapeamento dos padrões considerados e utilizadas na estimativa de todos dos atributos de solo. O erro médio de cada estimativa obtida pela técnica da krigagem ordinária foi comparado com o erro médio da estimativa obtida pela RNA e, posteriormente foram comparadas com os valores originais por meio do teste-t de Student. Os resultados mostram que a técnica de RNAs apresenta assertividade compatível à krigagem ordinária. O uso da técnica de RNA apresentou-se promissora para obter estimativas de atributos de solo empregando um número menor de amostras de solo. | ABSTRACT Soil physical and chemical analyses are relatively high-cost and time-consuming procedures. In the search for alternatives to predict these properties from a reduced number of soil samples, the use of Artificial Neural Networks (ANN) has been pointed out as a great computational technique to solve this problem by means of experience. This tool also has the ability to acquire knowledge and then apply it. This study aimed at using ANNs to estimate the physical and chemical properties of soil. The data came from the physical and chemical analysis of 120 sampling points, which were submitted to descriptive analysis, geostatistical analysis, and ANNs training and analysis. In the geostatistical analysis, the semivariogram model that best fitted the experimental variogram was verified for each soil property, and the ordinary kriging was used as an interpolation method. The ANNs were trained and selected based on their assertiveness in the mapping of considered standards, and then used to estimate all soil properties. The mean errors of ordinary kriging estimates were compared to those of ANNs and then compared to the original values using Student's t-Test. The results showed that the ANN had an assertiveness compatible with ordinary kriging. Therefore, such technique is a promising tool to estimate soil properties using a reduced number of soil samples.

Soil physical and chemical analyses are relatively high-cost and time-consuming procedures. In the search for alternatives to predict these properties from a reduced number of soil samples, the use of Artificial Neural Networks (ANN) has been pointed out as a great computational technique to solve this problem by means of experience. This tool also has the ability to acquire knowledge and then apply it. This study aimed at using ANNs to estimate the physical and chemical properties of soil. The data came from the physical and chemical analysis of 120 sampling points, which were submitted to descriptive analysis, geostatistical analysis, and ANNs training and analysis. In the geostatistical analysis, the semivariogram model that best fitted the experimental variogram was verified for each soil property, and the ordinary kriging was used as an interpolation method. The ANNs were trained and selected based on their assertiveness in the mapping of considered standards, and then used to estimate all soil properties. The mean errors of ordinary kriging estimates were compared to those of ANNs and then compared to the original values using Student's t-Test. The results showed that the ANN had an assertiveness compatible with ordinary kriging. Therefore, such technique is a promising tool to estimate soil properties using a reduced number of soil samples.

ABSTRACT The semi-arid region of Northeast Brazil is vulnerable to problems of water scarcity and salinity, resulting in low-quality irrigation water and the need to adopt cultivation strategies that make the production system viable. Given the above, this study aimed to evaluate emergence, growth, and production of colored cotton subjected to increasing levels of irrigation water salinity and organic matter doses. The experiment was carried out in a eutrophic Regolithic Neosol with a sandy loam texture in a greenhouse in the municipality of Campina Grande - PB, Brazil. A randomized block design was used in a 4 x 4 factorial scheme with three replicates, and the treatments corresponded to four levels of electrical conductivity of water - ECw (1.7, 3.4, 5.1, and 6.8 dS m-1) and four doses of organic matter - OM (0, 2.5, 3.5, and 4.5% based on soil volume). Increasing irrigation water salinity with ECw values above 1.7 dS m-1 reduced emergence, growth, and production of colored cotton, and the cotton seed weight was the variable most affected by salinity. Organic matter addition led to increased cotton growth and production, especially in terms of seed weight. Increasing doses of organic matter attenuated the effect of irrigation water salinity on the number of bolls in ‘BRS Jady’ cotton. | RESUMO A região semiárida do Nordeste Brasileiro é vulnerável aos problemas de escassez hídrica e salinidade, o que faz com que a maioria das águas utilizadas para irrigação nem sempre apresente boa qualidade, sendo necessária a adoção de estratégias de cultivo que viabilizem o sistema de produção. Diante do exposto, objetivou-se avaliar a emergência, o crescimento e a produção do algodoeiro de fibra colorida submetido a níveis crescentes de salinidade da água de irrigação e doses de matéria orgânica. O experimento foi conduzido em um Neossolo Regolítico Eutrófico de textura franco-arenosa em casa de vegetação no município de Campina Grande - PB. Utilizaram-se o delineamento experimental de blocos casualizados, em esquema fatorial 4 x 4, com três repetições, sendo os tratamentos compostos de quatro níveis de condutividade elétrica da água - CEa (1,7; 3,4; 5,1 e 6,8 dS m-1) e quatro doses de matéria orgânica - MO (0; 2,5; 3,5 e 4,5% em base do volume de solo).O aumento da salinidade da água de irrigação com CEa superior a 1,7 dS m-1 reduziu a emergência, o crescimento e a produção do algodoeiro colorido, sendo a massa de algodão em caroço a variável mais afetada. A adição de matéria orgânica promoveu acréscimos no crescimento e produção do algodoeiro, especialmente na massa de algodão em caroço. Doses crescentes de matéria orgânica atenuaram o efeito da salinidade da água de irrigação sobre o número de capulhos do algodoeiro ‘BRS Jady’.

The semi-arid region of Northeast Brazil is vulnerable to problems of water scarcity and salinity, resulting in low-quality irrigation water and the need to adopt cultivation strategies that make the production system viable. Given the above, this study aimed to evaluate emergence, growth, and production of colored cotton subjected to increasing levels of irrigation water salinity and organic matter doses. The experiment was carried out in a eutrophic Regolithic Neosol with a sandy loam texture in a greenhouse in the municipality of Campina Grande - PB, Brazil. A randomized block design was used in a 4 x 4 factorial scheme with three replicates, and the treatments corresponded to four levels of electrical conductivity of water - ECw (1.7, 3.4, 5.1, and 6.8 dS m-1) and four doses of organic matter - OM (0, 2.5, 3.5, and 4.5% based on soil volume). Increasing irrigation water salinity with ECw values above 1.7 dS m-1 reduced emergence, growth, and production of colored cotton, and the cotton seed weight was the variable most affected by salinity. Organic matter addition led to increased cotton growth and production, especially in terms of seed weight. Increasing doses of organic matter attenuated the effect of irrigation water salinity on the number of bolls in ‘BRS Jady’ cotton.

ABSTRACT Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha-1) and four levels of N (0, 67, 134, and 268 kg ha-1) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha-1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K. | RESUMO A adubação é importante para otimizar o crescimento e produtividade, sendo necessario para atividade agrícola. A adubação de solo deve aumentar o lucro líquido, que depende da eficiência de uso de nutrientes pela planta. O objetivo deste estudo foi avaliar a eficiência agronômica em berinjela sob diferentes doses de potássio (K) e nitrogênio (N). Quatro níveis de K (0, 54, 108 e 216 kg de K ha-1) e quatro níveis de N (0, 67, 134 e 268 kg de N ha-1) foram aplicados semanalmente via fertirrigação. As plantas mais altas e com maior diâmetro de caule foram obtidas com 165-175 kg ha-1 de N. A área foliar foi mais influenciada pelo nitrogênio em comparação com o potássio. Aplicações isoladas de diferentes doses de K não influenciaram a altura de planta, diâmetro de caule e matéria seca da folha. A eficiência agronômica do nitrogênio é reduzida com o aumento da dose de N e K.

Fertilization is important for the optimization of plant growth and yield, which are necessary for agronomic activities. Soil fertilization should increase net earnings that depend on nutrient use efficiency. The aim of this study was to evaluate the agronomic efficiency of eggplant under different doses of potassium (K) and nitrogen (N). Four levels of K (0, 54, 108, and 216 kg ha-1) and four levels of N (0, 67, 134, and 268 kg ha-1) were applied weekly by fertigation. The highest plant and the largest stem diameter were found with 165-175 kg ha-1 of N. Leaf area was more influenced by N than by K. Isolated application of different K doses did not statistically influence height plant, stem diameter, or leaf dry matter. The agronomic efficiency of nitrogen is reduced with increasing levels of N and K.

ABSTRACT The cultivation of irrigated guava in semi-arid areas highlights the need for information regarding its responses to irrigation water quality and the fertilization management that enables its exploitation. Thus, this study aimed to evaluate the effect of water salinity and nitrogen (N) doses on the growth and physiology of the guava cv. ‘Paluma’. The experiments was conducted in drainage lysimeters under field conditions in an experimental area at the Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande (CCTA/UFCG), Campus II, in Pombal, PB, Brazil. The experiment had a randomized block design, and treatments consisted of a 5 x 4 factorial arrangement corresponding to five levels of irrigation water electrical conductivity, ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1), and four N doses (70, 100, 130, and 160% of the recommended N dose). The 100% dose corresponded to 541.1 mg of N dm-3 of soil. Increments in irrigation water salinity from 0.3 dS m-1 led to a reduction in stomatal conductance, internal CO2 concentration, CO2 assimilation rate, transpiration, instantaneous water use efficiency, the number of leaves and branches, stem diameter, and absolute and relative growth rates. Nitrogen doses ranging from 378.7 to 865.7 mg of N dm-3 of soil did not affect gas exchange and plant growth. Although ‘Paluma’ guava growth was affected by increases in water salinity, these plants can be irrigated using water of up to 1.42 dS m-1 with an acceptable reduction of 10% in growth variables. The interaction between irrigation water salinity and N fertilization had no significant effect on any of the variables studied. | RESUMO O cultivo da goiabeira irrigada nas áreas semiáridas evidencia a necessidade de informações a respeito de suas respostas à qualidade da água de irrigação e ao manejo da adubação que possibilite sua exploração. Assim, objetivou-se estudar o efeito da salinidade da água combinada com doses de nitrogênio no crescimento e fisiologia da goiabeira cv. ‘Paluma’, em experimento conduzido em lisímetros de drenagem sob condições de campo em uma área experimental no Centro de Ciência e Tecnologia Agroalimentar da Universidade Federal de Campina Grande (CCTA/UFCG), Campus II de Pombal, PB. O delineamento experimental utilizado foi de blocos casualizados, com tratamentos arranjados em esquema fatorial 5 x 4, relativos a cinco níveis de condutividade elétrica da água de irrigação - CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogênio (70, 100, 130 e 160% de N recomendada), sendo a dose referente a 100% correspondeu a 541,1 mg de N dm-3 de solo. O aumento da salinidade da água de irrigação a partir de 0,3 dS m-1 promoveu redução na condutância estomática, concentração interna de CO2, taxa de assimilação de CO2, transpiração, eficiência instantânea no uso da água, número de folhas e ramos, diâmetro de caule, taxa de crescimento absoluto e relativo. Doses de nitrogênio variando de 378,7 a 865,7 mg de N dm-3 de solo não afetaram as trocas gasosas e o crescimento das plantas. Apesar do crescimento da goiabeira cv. Paluma ser afetado com o aumento da salinidade, é possível irrigar com água de até 1,42 dS m-1 ocorrendo redução aceitável de 10% nas variáveis de crescimento. Não houve efeito significativo da interação entre salinidade da água de irrigação e doses de adubação nitrogenada em nenhuma variável estudada.

The cultivation of irrigated guava in semi-arid areas highlights the need for information regarding its responses to irrigation water quality and the fertilization management that enables its exploitation. Thus, this study aimed to evaluate the effect of water salinity and nitrogen (N) doses on the growth and physiology of the guava cv. ‘Paluma’. The experiments was conducted in drainage lysimeters under field conditions in an experimental area at the Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande (CCTA/UFCG), Campus II, in Pombal, PB, Brazil. The experiment had a randomized block design, and treatments consisted of a 5 x 4 factorial arrangement corresponding to five levels of irrigation water electrical conductivity, ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1), and four N doses (70, 100, 130, and 160% of the recommended N dose). The 100% dose corresponded to 541.1 mg of N dm-3 of soil. Increments in irrigation water salinity from 0.3 dS m-1 led to a reduction in stomatal conductance, internal CO2 concentration, CO2 assimilation rate, transpiration, instantaneous water use efficiency, the number of leaves and branches, stem diameter, and absolute and relative growth rates. Nitrogen doses ranging from 378.7 to 865.7 mg of N dm-3 of soil did not affect gas exchange and plant growth. Although ‘Paluma’ guava growth was affected by increases in water salinity, these plants can be irrigated using water of up to 1.42 dS m-1 with an acceptable reduction of 10% in growth variables. The interaction between irrigation water salinity and N fertilization had no significant effect on any of the variables studied.