Intercropping system and the use of green manure with spontaneous species has been an alternative farming method applied to the productive sector of vegetables in the northeastern semi-arid region. The objective of this work was to determine which amount of Calotropis procera must be incorporated into the soil to provide the highest productive performance of the component crops and increase the profitability of the carrot and cowpea intercropping. The experimental design used was randomized complete blocks with five replicates. The treatments consisted of four amounts of C. procera incorporated into the soil: 10, 25, 40 and 55 t ha-1 on a dry basis. The characteristics evaluated in this intercropping system were: commercial productivity of carrot roots, yield of cowpea green grains, land equivalent ratios for component crops and for the  intercropped system, score of the canonical variable of the association, and the economic indicators of gross income, net income, rate of return, and net profit margin. The maximum agronomic efficiency of the carrot x cowpea intercropping was reached at the land equivalent ratio of 1.12, using 43.39 t ha-1 of C. procera biomass incorporated in the soil, while the maximum economic efficiency of the carrot and cowpea crops association was obtained at the net income of R$ 17,856.43 ha-1, in the amount of 40.60 t ha-1 of C. procera biomass added to the soil. | Sistema consorciado e uso de adubação verde com espécies espontâneas tem sido um método alternativo de cultivo aplicado ao setor produtivo de hortaliças na região semiárida nordestina. O objetivo deste trabalho foi determinar qual quantidade de Calotropis procera deve ser incorporada ao solo para proporcionar o melhor desempenho produtivo das culturas componentes e aumentar a rentabilidade do consórcio de cenoura e caupi. O delineamento experimental utilizado foi de blocos completos casualizados com cinco repetições. Os tratamentos consistiram de quatro quantidades de C. procera incorporadas ao solo: 10, 25, 40 e 55 t ha-1, em base seca. As características avaliadas neste sistema consorciado foram: produtividade comercial de raízes de cenoura, produtividade de grãos verdes de caupi, índices de uso eficiente da terra das culturas componentes e do consórcio, escore da variável canônica da associação e os indicadores econômicos renda bruta, renda líquida, taxa de retorno e margem de lucro líquido. A máxima eficiência agronômica do consórcio cenoura x caupi foi alcançada no índice de uso eficiente da terra de 1,12, utilizando-se 43,39 t ha-1 de biomassa de C. procera incorporada ao solo, enquanto a eficiência econômica máxima da associação cenoura x caupi foi obtida com a renda líquida de R$ 17.856,43 ha-1, na quantidade de 40,60 t ha-1 de biomassa de C. procera adicionada ao solo.

Intercropping system and the use of green manure with spontaneous species has been an alternative farming method applied to the productive sector of vegetables in the northeastern semi-arid region. The objective of this work was to determine which amount of Calotropis procera must be incorporated into the soil to provide the highest productive performance of the component crops and increase the profitability of the carrot and cowpea intercropping. The experimental design used was randomized complete blocks with five replicates. The treatments consisted of four amounts of C. procera incorporated into the soil: 10, 25, 40 and 55 t ha-1 on a dry basis. The characteristics evaluated in this intercropping system were: commercial productivity of carrot roots, yield of cowpea green grains, land equivalent ratios for component crops and for the intercropped system, score of the canonical variable of the association, and the economic indicators of gross income, net income, rate of return, and net profit margin. The maximum agronomic efficiency of the carrot x cowpea intercropping was reached at the land equivalent ratio of 1.12, using 43.39 t ha-1 of C. procera biomass incorporated in the soil, while the maximum economic efficiency of the carrot and cowpea crops association was obtained at the net income of R$ 17,856.43 ha-1, in the amount of 40.60 t ha-1 of C. procera biomass added to the soil.

Brave bean (Capparis flexuosa L.) is a Caatinga species that is used as forage, mainly during the dry season when some plant species lose their leaves. The aim of this study was to assess genetic diversity within and among brave bean populations using Random Amplified Polymorphic DNA (RAPD) markers. Brave bean leaves were collected from 30 accessions in the following municipalities of Paraíba state, Brazil: Barra de Santa Rosa (BSR), Cuité (C), São João do Cariri (SJC), Damião (D), Baraúna (B), and Picuí (P). DNA extraction followed the standard methodology of CTAB with modifications. RAPD analyses were carried out using 18 primers, and polymorphism of the amplified DNA fragments was visualized using agarose gel electrophoresis. Data were used to calculate Jaccard Similarity Coefficient values, which were then used to group samples with the Unweighted Pair Group Method with Arithmetic Mean. Cophenetic Correlation Coefficient, Stress, and Distortion Coefficient values were also calculated from these analyses. Band polymorphism was generated with 14 primers, but the sampled populations showed low numbers of polymorphic loci (27 in BSR, 18 in C, 7 in SJC, 9 in D, and 0 in B and P). The highest polymorphic information content was found in samples from the BSR (9 groups), C (22 groups), SJC (7 groups), and D (6 groups) municipalities. In the interpopulation analysis, 34 groups were formed, the matrices of which showed high cophenetic correlations (0.95 to 0.98), but low stress (12.9 to 17.45%) and distortion (3.05%). Therefore, results showed that there was genetic variability both among and within brave bean populations. | O feijão-bravo (Capparis flexuosa) é uma espécie nativa da Caatinga e é utilizada como forrageira, principalmente na estação seca onde parte das espécies vegetais perdem suas folhas. Objetivou-se estudar a diversidade genética dentro e entre populações de feijão-bravo usando marcadores RAPD. O estudo foi realizado no Laboratório de Biotecnologia Vegetal do CCA/UFPB. Foram coletadas folhas de 30 acessos de feijão-bravo/população nos seguintes municípios do estado da Paraíba: Barra de Santa Rosa (BSR), Cuité (C), São João do Cariri (SJC), Damião (D), Baraúna (B) e Picuí (P). A extração de DNA seguiu a metodologia de utilização do CTAB com modificações. Análises de RAPD foram realizadas usando 18 primers e o polimorfismo de fragmentos de DNA amplificados foi visualizado em gel de agarose após eletroforese. Os dados foram submetidos ao Coeficiente de Similaridade Jaccard, agrupados seguindo a UPGMA e calculou-se o Coeficiente de Correlação Cofenética, Estresse e Distorção. 14 primers geraram polimorfismo de banda, no entanto, as populações apresentaram baixo número de locos polimórficos (27 em BSR, 18 em C, 7 em SJC, 9 em D, 0 em B e P) sendo o maior conteúdo de informação polimórfica foi encontrado nos municípios de BSR (9 grupos), C (22 grupos), São João do Cariri (7 grupos) e D (6 grupos). Formou-se 34 grupos na análise interpopulacional. As matrizes formadas apresentaram altos índices de correlação cofenética (0,95 a 0,98), baixo estresse (12,9 a 17,45%) e distorção (3,05%). Portanto, há variabilidade genética entre e dentro de populações de feijão-bravo.

Brave bean (Capparis flexuosa L.) is a Caatinga species that is used as forage, mainly during the dry season when some plant species lose their leaves. The aim of this study was to assess genetic diversity within and among brave bean populations using Random Amplified Polymorphic DNA (RAPD) markers. Brave bean leaves were collected from 30 accessions in the following municipalities of Paraíba state, Brazil: Barra de Santa Rosa (BSR), Cuité (C), São João do Cariri (SJC), Damião (D), Baraúna (B), and Picuí (P). DNA extraction followed the standard methodology of CTAB with modifications. RAPD analyses were carried out using 18 primers, and polymorphism of the amplified DNA fragments was visualized using agarose gel electrophoresis. Data were used to calculate Jaccard Similarity Coefficient values, which were then used to group samples with the Unweighted Pair Group Method with Arithmetic Mean. Cophenetic Correlation Coefficient, Stress, and Distortion Coefficient values were also calculated from these analyses. Band polymorphism was generated with 14 primers, but the sampled populations showed low numbers of polymorphic loci (27 in BSR, 18 in C, 7 in SJC, 9 in D, and 0 in B and P). The highest polymorphic information content was found in samples from the BSR (9 groups), C (22 groups), SJC (7 groups), and D (6 groups) municipalities. In the interpopulation analysis, 34 groups were formed, the matrices of which showed high cophenetic correlations (0.95 to 0.98), but low stress (12.9 to 17.45%) and distortion (3.05%). Therefore, results showed that there was genetic variability both among and within brave bean populations.

The presence of microorganisms, especially during storage, can lead to the rapid deterioration of macauba fruits (Acrocomia aculeata) and reduce the quality of extracted oil for biodiesel production. An alternative to ensure the quality of the oil is the use of ozone gas, a oxidizing agent that has high antimicrobial and sanitizing power. The objective of this study was to evaluate the influence of high concentrations of ozone gas on macaúba fruit and its effect on the quality of the oil throughout storage for the production of biodiesel. Ozonation was performed 20 days after harvest using fruits with and without the epicarp. Ozone was applied at a concentration of 18.0 mg L-1 and a flow of 1.5 L min-1 for 10 h. After ozonation, the fruits were stored for different periods, and the physical-chemical parameters of the oil were evaluated. The ozonation of fruits without the epicarp visually reduced microorganism attack. In general, the ozonation process of macauba fruits maintained the visual characteristics of the fruits and the physical-chemical characteristics of the oil for biodiesel production compared to untreated fruits. The average acidity values of the oil were lower in the treatments with the ozone gas. Removal of the epicarp tends to facilitate the ozonation process, potentially by improving gas penetration into the fruit. | A presença de micro-organismo, especialmente durante o armazenamento, pode levar à deterioração rápida dos frutos de macaúba (Acrocomia aculeata) e reduzir a qualidade do óleo extraído para a produção de biodiesel. Uma alternativa para garantir a qualidade do óleo é o uso de gás ozônio, um poderoso agente oxidante que possui alto poder antimicrobiano e sanitizante. O objetivo deste estudo foi avaliar a influência do ozônio gasoso em alta concentração (18,0 mg L-1) em frutos de macaúba (com e sem epicarpo) e seu efeito sobre a qualidade do óleo durante todo o armazenamento para a produção de biodiesel. A ozonização foi realizada 20 dias após a colheita, utilizando frutas com e sem epicarpo. O ozônio foi aplicado na concentração de 18,0 mg L-1 e fluxo de 1,5 L min-1 durante 10 h. Após a ozonização, os frutos foram armazenados por diferentes períodos e foram avaliados os parâmetros físico-químicos do óleo. A ozonização de frutos sem epicarpo reduziu visualmente o ataque de micro-organismos. Em geral, o processo de ozonização de frutos de macauba manteve as características visuais dos frutos e físico-químicas do óleo para produção de biodiesel em relação ao controle não tratado. Os valores médios de acidez do óleo foram menores nos tratamentos com o gás ozônio. A remoção do epicarpo tende a facilitar o processo de ozonização, já que a retirada pode facilitar a penetração do gás no fruto.

The presence of microorganisms, especially during storage, can lead to the rapid deterioration of macauba fruits (Acrocomia aculeata) and reduce the quality of extracted oil for biodiesel production. An alternative to ensure the quality of the oil is the use of ozone gas, a oxidizing agent that has high antimicrobial and sanitizing power. The objective of this study was to evaluate the influence of high concentrations of ozone gas on macaúba fruit and its effect on the quality of the oil throughout storage for the production of biodiesel. Ozonation was performed 20 days after harvest using fruits with and without the epicarp. Ozone was applied at a concentration of 18.0 mg L-1 and a flow of 1.5 L min-1 for 10 h. After ozonation, the fruits were stored for different periods, and the physical-chemical parameters of the oil were evaluated. The ozonation of fruits without the epicarp visually reduced microorganism attack. In general, the ozonation process of macauba fruits maintained the visual characteristics of the fruits and the physical-chemical characteristics of the oil for biodiesel production compared to untreated fruits. The average acidity values of the oil were lower in the treatments with the ozone gas. Removal of the epicarp tends to facilitate the ozonation process, potentially by improving gas penetration into the fruit.

Nitrogen fertilization is a limiting factor for grapevine production; its excess or deficiency can cause changes in fruit quantity and quality. Thus, the objective of this work was to evaluate productive parameters of grapevines of the Isabel-Precoce cultivar subjected to nitrogen and organic fertilization in the western semiarid region of the state of Rio Grande do Norte (RN), Brazil. The experiment was conducted at the Experimental Farm of the Federal Rural University of the Semi-Arid Region, in Mossoró, RN, Brazil, during two production cycles. The soil of the area used was classified as dystrophic Red Argissolo (Udult) of sandy texture. The experiment was conducted in a randomized block design with six replications, using a 5×2 factorial arrangement, with 5 nitrogen fertilizer rates (0, 30, 60, 90, and 120 kg ha-1) and two organic fertilizer rates (0, and 20 m3 ha-1 of bovine manure). The production components number of bunches per plant, grape production per plant, grape yield, weight, length and width of bunches, number of berries per bunch, and ten-berry weight were evaluated. The nitrogen rates and organic fertilizer rates used were significant (p≤0.05) for all evaluated components. The N rate of 60 kg ha-1 combined with the organic fertilization generated the best results for the analyzed variables. N rates from 60 to 120 kg ha-1, applied singly or combined with organic fertilizer, hindered the production components of the Isabel-Precoce grapevines. | A adubação nitrogenada na videira apresenta-se como um fator limitante na produção, visto que seu excesso ou deficiência são capazes de propiciar alterações na quantidade e qualidade final dos frutos. Assim, o objetivo deste trabalho foi avaliar os parâmetros produtivos da videira ‘Isabel Precoce’ submetida a adubação nitrogenada e orgânica na região semiárida do Oeste Potiguar. O experimento foi implantado na Fazenda Experimental da UFERSA, em Mossoró, RN, cujo clima é semiárido. O solo da área é um Argissolo Vermelho Distrófico de textura arenosa. A pesquisa foi realizada em dois ciclos de produção. O delineamento experimental utilizado foi blocos casualizados com seis repetições, em esquema fatorial 5 x 2, que corresponderam a 5 doses de fertilizante nitrogenado (0, 30, 60, 90 e 120 kg ha-1), na ausência e presença de adubação orgânica (0 e 20 m3 ha-1 esterco bovino). Foram avaliados número de cachos por planta, produção por planta e produtividade, bem como peso, comprimento e largura dos cachos, número de bagas por cacho e peso de dez bagas. A aplicação das doses de nitrogênio (N), bem como o uso ou não de adubo orgânico (AO) no solo, conferiram efeito significativo (p≤0,05) para todos os componentes avaliados. A dose de 60 kg ha-1 de N na presença do AO foi a que proporcionou os melhores resultados nas variáveis analisadas. A elevação dos níveis de N, a partir da dose de 60 até 120 kg ha-1 combinadas ou não a fonte orgânica, inibiram os componentes produtivos da videira ´Isabel Precoce´.

Nitrogen fertilization is a limiting factor for grapevine production; its excess or deficiency can cause changes in fruit quantity and quality. Thus, the objective of this work was to evaluate productive parameters of grapevines of the Isabel-Precoce cultivar subjected to nitrogen and organic fertilization in the western semiarid region of the state of Rio Grande do Norte (RN), Brazil. The experiment was conducted at the Experimental Farm of the Federal Rural University of the Semi-Arid Region, in Mossoró, RN, Brazil, during two production cycles. The soil of the area used was classified as dystrophic Red Argissolo (Udult) of sandy texture. The experiment was conducted in a randomized block design with six replications, using a 5×2 factorial arrangement, with 5 nitrogen fertilizer rates (0, 30, 60, 90, and 120 kg ha-1) and two organic fertilizer rates (0, and 20 m3 ha-1 of bovine manure). The production components number of bunches per plant, grape production per plant, grape yield, weight, length and width of bunches, number of berries per bunch, and ten-berry weight were evaluated. The nitrogen rates and organic fertilizer rates used were significant (p=0.05) for all evaluated components. The N rate of 60 kg ha-1 combined with the organic fertilization generated the best results for the analyzed variables. N rates from 60 to 120 kg ha-1, applied singly or combined with organic fertilizer, hindered the production components of the Isabel-Precoce grapevines.

Muitas são as doenças causadas por patógenos habitantes do solo em melancia (Citrullus lanatus) no Brasil e no mundo. O objetivo do presente trabalho foi identificar e quantificar a frequência de fungos fitopatógenos associados ao “declínio” de ramas em melancia, presentes nas raízes de plantas daninhas nas principais áreas produtoras no estado do Rio Grande do Norte. Foram coletadas 10 amostras de raízes de espécies de plantas daninhas de maior prevalência em 16 áreas produtoras de melancia. As plantas foram identificadas e, calculada a respectiva frequência em campo. Foi realizado o isolamento fúngico das raízes, sendo posteriormente identificados os principais fungos associados ao declínio de ramas. Foram identificadas 13 espécies de plantas daninhas, pertencentes a nove famílias botânicas. As espécies de plantas daninhas que apresentaram as maiores frequências em campo foram Amaranthus spinosus (25,0%), Trianthema portulacastrum (18,8%), Commelina sp. (18,8%) e Boerhavia diffusa (12,5%). Das raízes das plantas daninhas que apresentaram maior frequência foram isolados os gêneros Macrophomina, Rhizoctonia e Monosporascus. O primeiro foi isolado de 12 espécies de plantas, o segundo de quatro espécies e o terceiro de duas espécies.

Many watermelon (Citrullus lanatus) diseases are caused by soilborne pathogens in Brazil and worldwide. The goal of this study was to identify and quantify the frequency of phytopathogenic fungi associated with watermelon root rot and vine decline that were also present in the roots of weeds in the major watermelon production regions in the state of Rio Grande do Norte, Brazil. We collected root samples from 10 of the most prevalent weed species in 16 watermelon producing areas. The plants were identified and their frequencies in the fields were calculated. The fungi found in the weed roots were isolated and the main genera associated with watermelon vine decline were identified. We identified 13 weed species belonging to nine botanical families. The weed species with the highest frequencies found in the field were Amaranthus spinosus (25.0%), Trianthema portulacastrum (18.8%), Commelina sp. (18.8%), and Boerhavia diffusa (12.5%). The fungi Macrophomina, Rhizoctonia, and Monosporascus were isolated from the roots of the weed plants. While Macrophomina was isolated from 12 different types of plants, Rhizoctonia and Monosporascus were isolated from four and two different plant species, respectively.