Eficiencia de solubilización de fósforo de aislados nativos guatemaltecos de Pseudomonas fluorescens / Phosphorus solubilization efficiency of native Guatemalan isolates of Pseudomonas fluorescens

El fósforo (P) es un elemento esencial en la producción agrícola, pero debido a su compleja dinámica en el suelo, solo una pequeña cantidad es aprovechable para las plantas, ya que la mayoría del P se encuentra en formas insolubles, especialmente, en suelos Andisoles de origen volcánico. Los microorganismos con capacidad solubilizadora de fósforo (MSF) son una alternativa para transformar el P a formas solubles y aprovechables por las plantas; además de brindar múltiples beneficios ambientales. Este trabajo identificó y evaluó in vitro, aislados nativos de Pseudomonas fluorescens Mingula, obtenidos de regiones guatemaltecas con suelos Andisoles que limitan la producción agrícola por la alta fijación de P. Se realizaron cultivos in vitro de la bacteria en medio National Botanical Research Instituteís phosphate growth (NBRIP), con fosfato tricálcico Ca3(PO4)2 como fuente de P insoluble y se midió el índice de solubilización de fósforo (ISF). Un total de 35 aislados de P. fluorescensfueron identificados y confirmados por PCR específico. El análisis de relaciones genéticas con el marcador AFLP, mostró dos grupos: el grupo A incluyó a los aislados con ISF mayores a 1.75, mientras el grupo B incluyó a aquellos con ISF menor a 1.75. La comparación de ISF entre los aislados y departamentos, demostró diferencia estadísticamente significativa (p < .001), con el aislado Pf_33 como más eficiente. Debido al potencial de solubilización de los aislados nativos del grupo genético A (ISF > 1.75), estos se recomiendan para futuras investigaciones que determinen su respuesta a condiciones de campo y estrategias para el desarrollo de biofertilizantes.

Phosphorus (P) is an essential element in agricultural production, but due to its complex dynamics in the soil, only a tiny amount is usable by plants. This is because most P is in insoluble forms, especially in volcanic Andisol soils. Microorganisms with phosphorus solubilizing capacity (MSF) are an alternative for transforming P into soluble forms usable by plants and providing multiple environmental benefits. This research identified and evaluated in vitro native isolates of Pseudomonas fluorescens Mingula, obtained from Guatemalan regions with Andisol soils that limit agricultural production due to high P fixation. In vitro cultures of the bacteria were grown on the National Botanical Research Instituteís phosphate medium (NBRIP), with tricalcium phosphate Ca3(PO4)2 as a source of insoluble P, and We measured the phosphorus solubilization index (PSI). We identified and confirmed a total of 35 isolates of P. fluorescens by specific PCR. Using the AFLP marker, genetic relationship analysis showed two groups: group A included isolates with PSI greater than 1.75, while group B included those with FSI less than 1.75. Comparing of PSI between isolates and departments showed statistically significant dif-ferences (p < 0.001), respectively, with the Pf_33 isolate as the most efficient. Because of the high solubilization potential of the native isolates of genetic group A (FSI > 1.75), We recommend future research to determine their response to field conditions and strategies for biofertilizer development.

Faunistic analyses of fruit fly species (Diptera: Tephritidae) in orchards surrounded by Atlantic Forest fragments in the metropolitan region of Curitiba, Paraná state, Brazil / Análise faunística de moscas-das-frutas (Diptera: Tephritidae) em pomares rodeados por fragmentos da Mata Atlântica na região metropolitana de Curitiba, Paraná, Brasil

Abstract The objective of this trial was to characterize the assemblage structure of fruit flies (Diptera: Tephritidae) by determining the diversity and faunal indices. Fruit flies were collected for ten years between 2003 and 2015 in six municipalities of the Metropolitan Region of Curitiba, Paraná. The orchards were divided into three crop protection strategies: organic, conventional, and integrated pest management. The characteristic of each community was determined using the Shannon-Wiener, Margalef, and Pielou's indexes. The frequency, constancy, and dominance indexes were also determined. Biological material was analyzed using the explanatory variables: site, crop, plant protection strategy, and susceptibility period. A total of 8,089 fruit flies were collected, of which 4,681 were females. The species Anastrepha daciformis Bezzi, A. dissimilis Stone, A. distincta Greene and A. pickeli Lima were recorded for the first time in Paraná State, the occurrence of three other species was recorded for the first time in the Metropolitan Region of Curitiba (A. montei Lima, A. obliqua Macquart, and A. sororcula Zucchi), in addition A. fraterculus (Wiedemann), A. grandis (Macquart) and Ceratitis capitata (Wiedemann). A. fraterculus accounted for 98.5% of the collected species. Only A. fraterculus and A. sororcula were found in fruits. Fruit flies occurred predominantly in peach trees cultivated under organic conditions. The Shannon index indicated that the municipality of Cerro Azul had the highest diversity and richness whereas apple orchards had the lowest diversity. Crops cultivated under organic conditions exhibited the highest diversity whereas those cultivated under conventional conditions had the highest evenness index. The largest specimens number was collected during the period of crop susceptibility.

Resumo O objetivo deste estudo foi caracterizar agrupamento de espécies de moscas-das-frutas (Diptera: Tephritidae) pela determinação da diversidade e dos índices faunísticos. As moscas-das-frutas foram coletadas por dez anos entre 2003 e 2015 em seis municípios da Região Metropolitana de Curitiba, no Paraná. Os pomares foram divididos em três estratégias de proteção de culturas: orgânica, convencional e integrada. A característica de cada comunidade foi determinada usando os índices de Shannon-Wiener, Margalef e Pielou. Os índices de freqüência, constância e dominância também foram determinados. O material biológico foi analisado utilizando as variáveis explicativas: local, cultura, estratégia de proteção e período de susceptibilidade. Foram coletadas 8.089 moscas-das-frutas, sendo 4.681 fêmeas. As espécies Anastrepha daciformis Bezzi, A. dissimilis Stone, A. distincta Greene e A. pickeli Lima foram registradas pela primeira vez no Estado do Paraná, e pela primeira vez, na Região Metropolitana de Curitiba, as espécies A. montei Lima, A. obliqua Macquart e A. sororcula Zucchi), além de A. fraterculus (Wiedemann), A. grandis (Macquart) e Ceratitis capitata (Wiedemann). A. fraterculus foi responsável por 98,5% das espécies coletadas. Apenas A. fraterculus e A. sororcula foram encontrados em frutos. As moscas-das-frutas ocorreram predominantemente em pessegueiros cultivados sob condições orgânicas. O índice de Shannon indicou que o município de Cerro Azul teve a maior diversidade e riqueza, enquanto que a cultura macieira teve a menor diversidade. As culturas sob condição orgânica exibiram a maior diversidade, enquanto as cultivadas em condições convencionais apresentaram o maior índice de uniformidade. O maior número de espécimes foi coletado durante o período de suscetibilidade à cultura.

Interação entre espécies forrageiras nativas e cultivadas em condições de semiárido: revisão / Interaction between native forage species and those cultivated under semi-arid conditions: a review / Interacción entre especies forrajeras nativas y cultivadas en condiciones de semiárido: revisión

O capim-aruana é uma nova opção de gramínea para implantação no semiárido. Ambiente que apresenta ocorrência natural de outras espécies como as espontâneas adaptadas as condições edafoclimáticas da região. É fato reconhecido a importância dessas plantas em meio as pastagens, pelo fato de aumentar a biomassa vegetal, servir de proteção do solo contra a erosão, aumentar a diversidade do pasto oferecendo opção de seletividade para o animal. Foi realizado um levantamento de informações disponíveis na literatura sobre a temática abordada, apresentando informações relevantes para melhor entendimento da temática. A identificação botânica ou citogenética das espécies que estão presentes na pastagem possibilita conhecer se determinada espécie possui potencial forrageiro ou pode causar algum dano à saúde animal como a intoxicação e permite escolher melhor a forma de manejo da área. Assim, conclui-se que o capim-aruana é uma alternativa interessante para ser adotada em sistemas de produção por aliar características adaptativas, agronômicas e nutricionais que visam incrementar a produção pecuária em sistemas de clima semiárido.(AU)

The Guinea grass is a new option for implantation in the Brazilian semi-arid region. That area presents the natural occurrence of other species such as the spontaneous ones already adapted to the edaphoclimatic conditions of the region. The importance of those plants amid the grazing land is recognized since they increase the offer of vegetal biomass, protect the soil against erosion, increase the grazing diversity by offering an option for the animals. A survey was performed seeking literature information on the addressed topic, presenting relevant information for its better understanding. The botanical or cytogenetic identification of the species present in the pasture allows determining if a given species has foraging potential or if it can cause harm to animal health, such as intoxication, and thus, provides better knowledge of choosing the best handling practices for the area. Therefore, it can be concluded that the Guinea grass is an interesting alternative to be adopted in production systems by combining adaptive, agronomic and nutritional characteristics that aim at increasing livestock production in semi-arid climate systems.(AU)

El capim-aruana es una nueva opción de gramínea para implantación en el semiárido. Ambiente que presenta ocurrencia natural de otras especies como las espontáneas adaptadas a las condiciones edáficas y climáticas de la región. Es un hecho reconocido la importancia de esas plantas en medio de los pastos, por el hecho de aumentar la biomasa vegetal, servir de protección del suelo contra la erosión, aumentar la diversidad del pasto ofreciendo opción de selectividad para el animal. Se realizó una investigación de informaciones disponibles en la literatura sobre el tema abordado, presentando informaciones relevantes para una mejor comprensión del tema. La identificación botánica o citogenética de las especies que están presentes en el pastoreo posibilita conocer si determinada especie posee potencial forrajero o puede causar algún daño a la salud animal, como la intoxicación, y permite escoger mejor la forma de manejo del área. Por lo tanto, concluimos que el capim-aruana es una alternativa interesante para ser adoptada en los sistemas de producción por combinar características adaptativas, agronómicas y nutricionales que apuntan a aumentar la producción ganadera en sistemas de clima semiárido.(AU)

Relationships of rice yield and quality based on genotype by trait (GT) biplot

ABSTRACT An experiment was conducted to examine the influencing characters on rice by using 64 rice genotypes, including four local landraces, four released cultivars and 56 mutant lines (M5) derived from these genotypes, with application of the genotype by trait (GT) biplot methodology. The first two principal components (PC1 and PC2) accounted for 46.6% of total variation in 64 genotypes. The polygon view of GT biplot suggested seven sections for 64 genotypes. The vertex G38 had good amounts of grain yield, panicle length, hundred grain weight, internodes length, plant height and fertility percentage. Generally based on vector view it was demonstrated that the selection of high grain yield would be performed via thousand grain weight, panicle weight and number of filled grain per panicle. These traits should be considered simultaneously as effective selection criteria evolving high yielding rice genotypes because of their large contribution to grain yield. The genotypes G2, G4 and G7 could be considered for the developing of desirable progenies in the selection strategy of rice improvement programs. This study revealed GT biplot can graphically display the interrelationships among traits. In conclusion, it is recommended the use of GGE biplot to identify superior genotypes for simultaneous improvement of several traits.

Palisadegrass effects on N fertilizer dynamic in intercropping systems with corn

ABSTRACT Corn grain yield, nitrogen (N) fertilizer efficiency and distribution to corn alone and three forms of corn and palisadegrass (Urochloa spp.) intercropping implantation was investigated. A field experiment with 15N labeling fertilizer was performed in randomized block design. No form of palisadegrass intercropping implantation affected corn grain yield, total N accumulation and N use efficiency (NUE), which were 8.7 t ha-1, 205 kg ha-1 and 37% respectively. The palisadegrass produced on average 1.9 t of dry mass, absorbing a maximum of 6 kg ha-1 or 5.5% of N fertilizer during corn growing. Furthermore, the palisadegrass did not affect N fertilizer distribution in soil-plant system, in which 28.2% was recovered in the soil and 40.4% in the plants (corn + palisadegrass). The results show that for the three intercropping implantation methods the palisadegrass did not compete with corn for N fertilizer.

Maize dry matter production and macronutrient extraction model as a new approach for fertilizer rate estimation

ABSTRACT Decision support for nutrient application remains an enigma if based on soil nutrient analysis. If the crop could be used as an auxiliary indicator, the plant nutrient status during different growth stages could complement the soil test, improving the fertilizer recommendation. Nutrient absorption and partitioning in the plant are here studied and described with mathematical models. The objective of this study considers the temporal variation of the nutrient uptake rate, which should define crop needs as compared to the critical content in soil solution. A uniform maize crop was grown to observe dry matter accumulation and nutrient content in the plant. The dry matter accumulation followed a sigmoidal model and the macronutrient content a power model. The maximum nutrient absorption occurred at the R4 growth stage, for which the sap concentration was successfully calculated. It is hoped that this new approach of evaluating nutrient sap concentration will help to develop more rational ways to estimate crop fertilizer needs. This new approach has great potential for on-the-go crop sensor-based nutrient application methods and its sensitivity to soil tillage and management systems need to be examined in following studies. If mathematical model reflects management impact adequately, resources for experiments can be saved.

Where is sugarcane cropping expanding in the brazilian cerrado, and why? A case study

ABSTRACT Sugarcane growing area in Brazil sharply expanded between 2000 and 2010 due to the increasing world demand for sugar and ethanol. Since this expansion of sugarcane is said to occur in areas covered by degraded pastures, it is likely not threatening the environment or food production. In order to verify this assumption, we investigate at farm and field levels which types of land use sugarcane cropping replaced between 2005 and 2010 and the reasons for farmers shifting or not shifting to sugarcane, as a case study in two counties in the state of Goiás. Within the studied period, sugarcane cropping expansion was related to large farms, lower risk perceived by farmers, and higher profitability compared with soybean and beef cattle-raising. For smallholders, particularly dairy farmers, the need to comply with the set-aside rules under Brazilian Forest Code (Código Florestal Brasileiro) made a shift to sugarcane less attractive, as it would have forced them to reduce farm cultivable area, with loss of incomes. From 30,408 ha under sugarcane surveyed, 45.7% had used to be pastures, 31% had previously been pastures rotated with soybean and maize, and 23.3% had been cropped exclusively with soybean or maize.

Frequências de cortes em nove leguminosas forrageiras tropicais herbáceas cultivadas ao sol e sob plantação florestal / Cutting frequencies of nine herbaceous tropical forage legumes cultivated under full sun light and under a forest plantation

O objetivo deste trabalho foi estudar a produção e o valor nutritivo de nove espécies de leguminosas forrageiras herbáceas tropicais, cultivadas sob dois níveis de irradiação luminosa e seis frequências de corte na estação chuvosa, em Anhembi (SP), Brasil. Parcelas puras foram estabelecidas ao sol e sob plantação de Eucalyptus grandis, com 8 anos de idade, com 1.000 árvores/ha, que interceptou mais de 80% da radiação luminosa incidente. Avaliou-se a taxa de acúmulo de matéria seca, a proteína bruta e a digestibilidade in vitro da matéria seca em amostras de plantas colhidas em intervalos de 30, 60, 90 e 180 dias, com cortes adicionais aos 120 e 150 dias. Sob pleno sol, as leguminosas testadas toleraram cortes mais frequentes (intervalos de 30 - 90 dias), exceto o Lablab. Na sombra, o grau de tolerância variou conforme a espécie; em termos de produção de MS e de persistência, a Centrosema e a Puerária se destacaram dentre as demais leguminosas comparadas, quando os cortes foram realizados em intervalos de 60 dias, enquanto o Arachis e o Estilosantes foram os mais produtivos quando os cortes ocorreram em intervalos de 120 dias, mantendo o valor nutricional. O Alysicarpus e a Aeschynomene não persistiram sob o nível de sombreamento que prevaleceu nesse experimento.

The aim of this study was to evaluate the production and nutritive value of nine tropical legumes under two light intensities and six cutting regimens in the wet season, in Anhembi (SP) - Brazil. Pure stands were established in full light and under an eight-year-old eucalyptus plantation with 1.000 plants per hectare. The trees intercepted over80% of the incident radiation. Dry matter herbage accumulation, dry matter in vitro digestibility and crude protein under the cutting intervals 30, 60, 90 and 180 days, with additional cuttings at 120 and 150 days were evaluated. With the exception of Lablab, all other tested legume species tolerated higher cutting frequency under when grown under full sun light then under shade. The degree of shade-tolerance varied according to the species; Centrosema and Pueraria produced well at cutting intervals of 60 days, showing higher dry matter production and persistence while Arachis and Stylosanthes showed better results under longer cutting intervals, keeping the nutritional value, and can be indicated for differential grazing. Alysicarpus and Aeschynomene did not persist under the prevailing conditions.

Genetic variability in G2 and F2 region between biological clones of human respiratory syncytial virus with or without host immune selection pressure

Human respiratory syncytial virus (HRSV) is an important respiratory pathogens among children between zero-five years old. Host immunity and viral genetic variability are important factors that can make vaccine production difficult. In this work, differences between biological clones of HRSV were detected in clinical samples in the absence and presence of serum collected from children in the convalescent phase of the illness and from their biological mothers. Viral clones were selected by plaque assay in the absence and presence of serum and nucleotide sequences of the G2 and F2 genes of HRSV biological clones were compared. One non-synonymous mutation was found in the F gene (Ile5Asn) in one clone of an HRSV-B sample and one non-synonymous mutation was found in the G gene (Ser291Pro) in four clones of the same HRSV-B sample. Only one of these clones was obtained after treatment with the child's serum. In addition, some synonymous mutations were determined in two clones of the HRSV-A samples. In conclusion, it is possible that minor sequences could be selected by host antibodies contributing to the HRSV evolutionary process, hampering the development of an effective vaccine, since we verify the same codon alteration in absence and presence of human sera in individual clones of BR-85 sample.

The use of halloysite clay and carboxyl-functionalised multi-walled carbon nanotubes for recombinant LipL32 antigen delivery enhanced the IgG response

We studied the feasibility of using halloysite clay nanotubes (HNTs) and carboxyl-functionalised multi-walled carbon nanotubes (COOH-MWCNTs) as antigen carriers to improve immune responses against a recombinant LipL32 protein (rLipL32). Immunisation using the HNTs or COOH-MWCNTs significantly increased the rLipL32-specific IgG antibody titres (p < 0.05) of Golden Syrian hamsters. None of the vaccines tested conferred protection against a challenge using a virulent Leptospira interrogans strain. These results demonstrated that nanotubes can be used as antigen carriers for delivery in hosts and the induction of a humoral immune response against purified leptospiral antigens used in subunit vaccine preparations.

Bromatological composition and dry matter digestibility of millet cultivars subjected to nitrogen doses / Composição bromatológica e digestibilidade da massa seca de cultivares de milheto submetidos à doses de nitrogênio

The bromatological composition and in vitro dry matter digestibility of millet cultivars were assessed for different nitrogen doses and two sowing seasons in the Ceres municipality of Goiás state, Brazil. The treatments consisted of three millet cultivars (ADR-7010, ADR-500 and BRS-1501), four nitrogen (N) doses (0, 50, 100 and 200kg ha-1 of N) and two sowing seasons. Three replicates and a randomised block design with a 3 x 4 x 2 factorial scheme were used. Two cuttings were performed in each season when plants reached an average height of 0.70 cm. No significant interactions were observed between or among cultivars for N doses and dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents. The DM, CP, NDF and ADF contents were significantly different between N doses. The DM and CP contents increased as the N dose increased to 100kg ha-1. The maximum DM and CP contents were 11.14 and 22.53 percent, respectively. The NDF and ADF contents were higher in the control treatment (60.11 and 30.01 percent, respectively). In addition, the lowest ADF and NDF concentrations occurred at an N dose of 50kg ha-1 (56.33 and 30.23 percent, respectively). The DM contents were higher for the February sowing, with an average of 10.59 percent. The highest CP and ADF contents were found for the December sowing (22.46 and 31.58 percent, respectively). No significant differences were found for millet cultivars, N doses or sowing seasons. A significant interaction was found between sowing season and millet cultivar. The BRS-1501 cultivar had a higher in vitro dry matter digestibility in the December/2010 sowing (73.88 percent)...

Foram avaliadas a composição bromatológica e a digestibilidade in vitro da massa seca de cultivares de milheto, sob doses de nitrogênio, em duas épocas de semeadura, no município de Ceres, Goiás. Os tratamentos foram constituídos por três cultivares de milheto: (ADR-7010, ADR-500 e BRS-1501) e quatro doses de N (0, 50, 100 e 200kg ha-1 de N) e duas épocas de semeadura, com três repetições. Utilizou-se o delineamento de blocos ao acaso em esquema fatorial 3x4x2. O fatorial foi avaliado em duas épocas de semeadura (dezembro/2010 e fevereiro/2011). Foram realizados dois cortes em cada época, quando as plantas atingiram, em média, 0,70m de altura. Não foi observada interação significativa entre as cultivares e dose de N e para os teores de MS, PB, FDN, FDA. Entre as cultivares de milheto, não houve diferença significativa para as mesmas variáveis. Ocorreu diferença significativa para os teores de MS, PB, FDN e FDA, entre as doses de N. Os teores de MS e PB aumentaram até a dose de 100kg ha-1 de N. Os teores máximos de MS e PB foram de 11,14 por cento e 22,53 por cento, respectivamente. Os teores de FDN (60,11 por cento) e FDA (30,01 por cento) foram maiores no tratamento controle, enquanto as menores concentração foram determinadas com a aplicação da dose equivalente a 50kg ha-1 de N, em que o FDN foi de 56,33 por cento e o FDA de 30,23 por cento. Os teores de MS foram maiores na semeadura de fevereiro, com média de 10,59 por cento. Os maiores teores de PB (22,46 por cento) e FDA (31,58 por cento) foram determinados na semeadura de dezembro. Não foram observadas diferenças significativas para as cultivares de milheto, as doses de N e as épocas de semeadura. Ocorreu efeito significativo para a interação entre épocas de semeadura e cultivares de milheto. A cultivar BRS-1501 apresentou maior DIVMS na semeadura de dezembro/2010 (73,88 por cento)...

Phenolic compounds and vitamins in wild and cultivated apricot (Prunus armeniaca L) fruits grown in irrigated and dry farming conditions

BACKGROUND: Turkey is the main apricot producer in the world and apricots have been produced under both dry and irrigated conditions in the country. In this study, phenolic compounds and vitamins in fruits of one wild (Zerdali) and three main apricot cultivars ('Cataloglu', 'Hacihaliloglu' and 'Kabaasi') grown in both dry and irrigated conditions in Malatya provinces in Turkey were investigated. RESULTS: The findings indicated that higher content of phenolic compounds and vitamins was found in apricot fruits grown in irrigated conditions. Among the cultivars, 'Cataloglu' had the highest rutin contents both in irrigated and dry farming conditions as 2855 µg in irrigated and 6952 µg per 100 g dried weight base in dry conditions and the highest chlorogenic acid content in irrigated and dry farming conditions were measured in fruits of 'Hacihaliloglu' cultivar as 7542 µg and 15251 µg per 100 g dried weight base. Vitamin C contents in homogenates of fruit flesh and skin was found to be higher than ß-caroten, retinol, vitamin E and lycopen contents in apricot fruits both in irrigated and dry farming conditions. CONCLUSION: The results suggested that apricot fruits grown in both dry and irrigated conditions had high health benefits phytochemicals and phytochemical content varied among cultivars and irrigation conditions as well. However, more detailed biological and pharmacological studies are needed for the demonstration and clarification of health benefits of apricot fruits.

Phosphate solubilizing ability of Emericella nidulans strain V1 isolated from vermicompost.

Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are largely replenished by chemical fertilizers. The present study was aimed to isolate efficient phosphate solubilizing fungal strains from Eisenia fetida vermicompost. Out of total 30 fungal strains the most efficient phosphate solubilizing one was Emericella (Aspergillus) nidulans V1 (MTCC 11044), identified by custom sequencing of β-tubulin gene and BLAST analysis. This strain solubilized 13 to 36% phosphate from four different rock phosphates. After three days of incubation of isolated culture with black Mussorie phosphate rock, the highest percentage of phosphate solubilization was 35.5±1.01 with a pH drop of 4.2±0.09. Kinetics of solubilization and acid production showed a linear relationship until day five of incubation. Interestingly, from zero to tenth day of incubation, solubility of soil phosphate increased gradually from 4.31±1.57 to 13.65±1.82 (mg kg-1) recording a maximum of 21.23±0.54 on day 45 in respect of the V1 isolate. Further, enhanced phosphorus uptake by Phaseolus plants with significant pod yield due to soil inoculation of Emericella nidulans V1 (MTCC 11044), demonstrated its prospect as an effective biofertilizer for plant growth.

A review on soil carbon accumulation due to the management change of major Brazilian agricultural activities / Uma revisão sobre o acúmulo de carbono no solo devido a mudança de manejo nas principais atividades agrícolas do Brasil

Agricultural areas deal with enormous CO2 intake fluxes offering an opportunity for greenhouse effect mitigation. In this work we studied the potential of soil carbon sequestration due to the management conversion in major agricultural activities in Brazil. Data from several studies indicate that in soybean/maize, and related rotation systems, a significant soil carbon sequestration was observed over the year of conversion from conventional to no-till practices, with a mean rate of 0.41 Mg C ha-1 year-1. The same effect was observed in sugarcane fields, but with a much higher accumulation of carbon in soil stocks, when sugarcane fields are converted from burned to mechanised based harvest, where large amounts of sugarcane residues remain on the soil surface (1.8 Mg C ha-1 year-1). The higher sequestration potential of sugarcane crops, when compared to the others, has a direct relation to the primary production of this crop. Nevertheless, much of this mitigation potential of soil carbon accumulation in sugarcane fields is lost once areas are reformed, or intensive tillage is applied. Pasture lands have shown soil carbon depletion once natural areas are converted to livestock use, while integration of those areas with agriculture use has shown an improvement in soil carbon stocks. Those works have shown that the main crop systems of Brazil have a huge mitigation potential, especially in soil carbon form, being an opportunity for future mitigation strategies.

Áreas agrícolas trocam enormes fluxos de CO2, oferecendo uma oportunidade para mitigar o efeito estufa. Neste trabalho, estudou-se o potencial de sequestro de carbono em razão da conversão no manejo das principais atividades agrícolas do Brasil. Dados de vários estudos têm indicado que no sistema soja/milho e nas respectivas rotações, ocorre um sequestro de carbono no solo significativo ao longo dos anos de conversão do plantio convencional para o plantio direto, com uma média de 0,41 Mg C ha-1 ano-1. O mesmo efeito tem sido observado nos canaviais, porém há maiores acúmulos de carbono no solo quando as áreas de cana-de-açúcar são convertidas da colheita baseada na queima para a mecanizada, em que grandes quantidades de palha são deixadas na superfície do solo (1,8 Mg C ha-1 ano-1). Esse maior potencial de acúmulo de carbono no solo nos canaviais, comparado com outras culturas, está diretamente relacionado com a maior produção primária dessa cultura. Apesar disso, muito desse potencial de sequestro é perdido, uma vez que os canaviais são reformados, sob preparo intensivo do solo. As áreas de pasto mostram uma depleção nos estoques de carbono, quando convertidas de áreas naturais; porém, a integração dessas áreas com agricultura pode promover o aumento nos estoques de carbono do solo. Os trabalhos têm mostrado que as principais atividades agrícolas do Brasil possuem um grande potencial de mitigação, especialmente na forma de acúmulo de carbono no solo, sendo uma oportunidade para estratégias futuras.

Consórcio de manjericão (Ocimum basilicum L. ) e alface sob dois arranjos de plantas / Intercrop of basil (Ocimum basilicum L. ) and lettuce under two plant arrangements

Ocimum basilicum L. (Lamiaceae) é comercialmente utilizada como aromatizante ou condimento preparado com suas folhas verdes e aromáticas, que podem ser usadas frescas ou secas. O objetivo deste trabalho foi avaliar a produção de biomassa de manjericão sob duas ou três fileiras no canteiro, consorciado ou não com alface. O manjericão e a alface foram alocados no campo em experimento conjunto, sendo constituídos cinco tratamentos da seguinte forma: duas fileiras solteiras de manjericão (M2) espaçadas de 0,50 m; três fileiras solteiras de manjericão espaçadas de 0,33 m (M3); quatro fileiras solteiras de alface espaçadas de 0,25 m (A4); duas fileiras solteiras de manjericão consorciadas com quatro fileiras de alface (M2A4) e três fileiras de manjericão consorciada com quatro fileiras de alface (M3A4). O delineamento utilizado foi em blocos casualizados, com oito repetições. As plantas de alface foram colhidas aos 48 dias após o transplantio e as de manjericão, em duas épocas, aos 96 e 113 dias após o transplantio (DAT). O consórcio não influenciou as áreas foliares nem as produções de folhas ou inflorescências do manjericão nem de cabeças comerciais ou não-comerciais da alface. No entanto, quanto ao arranjo de plantas, na segunda época de colheita, as plantas de manjericão cultivadas sob duas fileiras tiveram maior área foliar (2.076,99 cm² planta-1) e maior massa fresca de folhas (5.012,53 kg ha-1). Considerando-se que os valores da Razão de Área Equivalente - RAE na primeira e segunda colheita do manjericão foram maiores que 1,0, conclui-se que o consórcio manjericão com alface é viável. Recomenda-se o arranjo de três fileiras de manjericão alternadas com quatro fileiras de alface, e colheita aos 96 DAT, por ter tido RAE de 2,01.

Ocimum basilicum L. (Lamiaceae) is used commercially as flavoring or seasoning that was prepared with its green and aromatic leaves, which can be used fresh or dried. The aim of this work was to evaluate yield of biomass of basil under two or three rows per plot, intercropped or not with lettuce. Basil and lettuce were planted at field in joined experiment, which established five treatments: two rows of basil in monocrop system (M2) spaced 0.50 m; three rows of basil in monocrop system spaced 0.33 m (M3); four rows of lettuce in monocrop system spaced 0.25 m (A4); two rows of basil in monocrop system and intercropped with four rows of lettuce (M2A4) and three rows of basil intercropped with four rows of lettuce (M3A4). Used design was randomized blocks with eight replications. Lettuce plants were harvested on 48 days after transplanting and basil plants were harvested in two dates, on 96 and on 113 days after transplanting (DAT). Intercrop did not influence on foliar area neither on yields of leaves of inflorescences of basil neither on commercial or non-commercial lettuce heads. Although, regarding plant arrangement, on second harvest date, basil plants that were cultivated under two rows had the greatest foliar area (2,076.99 cm² plant-1) and the greatest fresh masses of leaves (5,012.53 kg ha-1). Considering that the values of Equivalent Area Ration in the first and the second harvest of basil were higher than 1.0. It was concluded that to intercrop basil with lettuce is viable. It is recommended the arrangement of three rows of basil alternated with four rows of lettuce, with harvested at 96 DAT, because it had EAR of 2.01.

Influencia de las condiciones de cultivo y del momento óptimo de cosecha en Artemisia annua L / Influence of growing conditions and of the optimal harvesting time on Artemisia annua L

Introducción: Artemisia annua L es una planta medicinal de gran interés y es importante precisar los aspectos agrícolas que garanticen su adecuado cultivo. Objetivos: determinar la influencia del cultivo a pleno sol y a la sombra y de la cosecha a diferentes horas y edades de la planta en la producción de biomasa y de los principios activos. Métodos: se utilizaron canteros a plena exposición solar y con determinada disminución de la luz para estudiar las condiciones de cultivo y en las investigaciones del momento de cosecha, en la recolección a diferentes horas del día: 9:00 am, 26 ºC; 11:00 am, 30 ºC; 1:00 pm, 32 ºC; 3:00 pm 33 ºC se seleccionaron plantas cultivadas a pleno sol, de 6 meses de edad; en el otro experimento se evaluó en plantas procedentes de semilleros establecidos en 2 fechas: 5 de noviembre y 8 diciembre, la recolección de la parte aérea a diferentes edades: 5, 6 y 7 meses. Se valoró la producción de biomasa, el contenido de artemisinina y adicionalmente el de aceite esencial y el de alcanfor. La extracción del aceite esencial se realizó por hidrodestilación y la de artemisinina y alcanfor por cromatografía gaseosa, la determinación de la presencia de estos dos componentes se realizó por cromatografía en capa delgada y además se valoraron los parámetros farmacognósticos: sustancias solubles en agua y en alcohol. Resultados: se encontraron pocas diferencias en cuanto al rendimiento de la parte aérea en las dos formas de cultivo, pero sí se obtuvo mayor contenido de artemisinina, aceite esencial y alcanfor en el cultivo a pleno sol. La mejor hora para realizar la cosecha es la mañana...

Introduction: Artemisia annua L is medicinal plant of great interest, and therefore it is important to specify exactly the agricultural elements supporting its proper growing. Objectives: to determine the influence of growing this plant in the sun and in the shade and of harvesting at different hours and plant ages in the production of biomass and active principles. Methods: flowerbeds were placed in the sun and in dimmed light conditions in order to study the growing conditions. In the research conducted at the time of harvest, plants grown in the sun, of 6 months of age and at various day hours: 9:00 am at 26 ºC; 11:00 am at 30 ºC; 1:00 pm at 32 ºC, and 3:00 pm at 33 ºC were harvested. In the other experiment, the harvest of the aerial parts of the plants coming from seedbeds created on November 5th and on December 8th and aged 5, 6 and 7 months was evaluated. The production of biomass, the content of artemisinin and additionally that of the essential oil and camphor were assessed. The extraction of the essential oil using hydrodistillation and that of artemisinin and the camphor by gas chromatography, the detection of the these two components was made by thin-layer chromatography and also the pharmacognostic parameters such as water- and alcohol-soluble substances were evaluated. Results: there were little differences in aerial parts yielding in the two growing methods but there was high content of artemisinin, essential oil and camphor in plants grown in the sun. The better time interval for harvest is the morning...

Incidence of keratinophilic fungi in waterlogged condition of paddy soil.

Prevalence of keratinophilic fungi was observed in paddy field soil during different stages of cultivation viz., transplanting, tillering, milking and maturation. Out of total 76 soil samples, 65 soil samples were found to be positive for the keratinophilic fungi. Fourteen species belonging to a single genus Chrysosporium were isolated through out the cropping season. C. keratinophilum (17.1%) followed by C. tropicum (13.15%) were found to be the most dominating geophilic species. The highest percent distribution of keratinophilic fungi appeared during the milking stage (100%) of paddy cultivation, followed by the maturation stage (89.47%).

Combinatorial effects of distillery and sugar factory effluents in crop plants.

Under the reutilization and recycling strategy of industrial effluents, treated distillery and sugar factory mixed effluent was used in petridish culture experiments to investigate its effect on seed germination and seedling growth in wheat, garden pea, black gram and mustard. The seed germination and seedling growth were significantly reduced with increase in concentration of the effluent. The fresh matter was found significantly increased in barley (1.16 g per seedling in 25% dilution level of effluents in comparison to 0.93 in control), while other higher dilution levels reduce it. Wheat, garden pea, black gram, mustard invariably showed inhibition in fresh weight. Dry weight was found consistently reduced or unchanged in different treatments. Total chlorophyll contents in barley were significantly increased in different treatments (2.351 and 2.721 mg/g fresh weight of tissue at 25, 50% dilution levels in comparison to 1.781 of control) while in other crop it was reduced alloverthe treatments. Amylase activity in wheat, garden pea, black gram and mustard was reduced in all the treatments. Only in barley its level was enhanced from 0.76 to 0.85, 0.96, 0.81 in 25, 50, 75% dilution levels of the effluent mixture respectively Based on the data of different crops barley was found to be highly tolerant as the 25 and 50% dilution levels of combined effluents. It showed no change in germination %, while seedling growth was increased in lower dilution levels of combined effluent as compared to control Barley>garden pea>wheat>black gram>mustard gradually showed increased level of sensitivity respectively Most detrimental effects were seen in mustard. This toxicity might be due to excess of nutrients, beyond the limits of tolerance. Therefore, the higher concentration of mixed effluent was not advisable for irrigation purpose, however it could be used for irrigation purpose after proper treatment and dilution (one part treated effluent and five parts of available irrigation water), as this dilution level was found growth and yield promotory