Melon fruit quality front mildew incidence and management of nitrogen and potassium topdressing

This work aimed to evaluate the application effect of different dosages of nitrogen and potassium topdressing on mildew severity and on yield and fruit quality of melon. The three cultivars, Jangada, Gaucho Casca de Carvalho and Gaucho Redondo Cone Sul were evaluated in Cerrado (savannah) and floodplain areas. At 34 days after sowing (DAS) the topdressing treatments with different dosages of nitrogen and potassium were applied. The mildew severity estimation started at 56 DAS and was performed in five-days intervals until the harvesting of the fruits. The yield and physicochemical characteristics of the collected fruits were evaluated at harvest. There was no significative interaction among nitrogen and potassium topdressing, the cultivars and cultivated areas. However, there was significative differences when the factors were analyzed in separate. The cultivar Gaucho Redondo Cone Sul showed a significant linear increase in the area under the disease progress curve and higher productivity on cerrado compared to the remaining cultivars. The cultivar Gaucho Casca de Carvalho produced heavier and with higher °Brix fruits on cerrado. It is possible to conclude that the applied topdressings did not reduce the mildew severity in all tested cultivars, but they increased the yield in the floodplain area without modifying the physicochemical characteristics of the pulp on the evaluated melon fruits.This work aimed to evaluate the application effect of different dosages of nitrogen and potassium topdressing on mildew severity and on yield and fruit quality of melon. The three cultivars, Jangada, Gaucho Casca de Carvalho and Gaucho Redondo Cone Sul were evaluated in Cerrado (savannah) and floodplain areas. At 34 days after sowing (DAS) the topdressing treatments with different dosages of nitrogen and potassium were applied. The mildew severity estimation started at 56 DAS and was performed in five-days intervals until the harvesting of the fruits. The yield and physicochemical characteristics of the collected fruits were evaluated at harvest. There was no significative interaction among nitrogen and potassium topdressing, the cultivars and cultivated areas. However, there was significative differences when the factors were analyzed in separate. The cultivar Gaucho Redondo Cone Sul showed a significant linear increase in the area under the disease progress curve and higher productivity on cerrado compared to the remaining cultivars. The cultivar Gaucho Casca de Carvalho produced heavier and with higher °Brix fruits on cerrado. It is possible to conclude that the applied topdressings did not reduce the mildew severity in all tested cultivars, but they increased the yield in the floodplain area without modifying the physicochemical characteristics of the pulp on the evaluated melon fruits

Efficiency of application of Trichoderma on the physiological quality and health of cowpea seeds

One of the main causes of low productivity of cowpea crops in Brazil is the use of low quality seeds. Low quality seeds have a high degree of infestation by phytopathogens, mainly fungi. Seed treatment with biological control agents, such as fungi of the genus Trichoderma, is a useful alternative to reduce or inhibit the transmission of diseases via seeds. In view of the above, this study aims to evaluate the physiological and sanitary quality of cowpea seeds treated with conidia of Trichoderma sp. (1.2, 2.4, 4.8 and 9.6 x 108 CFU g-1). We evaluated the germination and the sanity of seeds, length of seedling radicles, and production of indole acetic acid (IAA) by fungi. The experimental design was completely randomized in all experiments. In general, there was a predominance of Fusarium spp. and Rhizoctonia solani. The treatment of seeds with the conidia of Trichoderma sp. was positive for the parameters related to germination and radicle length of cowpea beans up to the concentration 4.8 x 108 CFU g-1. We conclude that the application of Trichoderma sp. was efficient in reducing the incidence of Fusarium spp., and promoted the germination and elongation of the radicle in cowpea.One of the main causes of low productivity of cowpea crops in Brazil is the use of low quality seeds. Low quality seeds have a high degree of infestation by phytopathogens, mainly fungi. Seed treatment with biological control agents, such as fungi of the genus Trichoderma, is a useful alternative to reduce or inhibit the transmission of diseases via seeds. In view of the above, this study aims to evaluate the physiological and sanitary quality of cowpea seeds treated with conidia of Trichoderma sp. (1.2, 2.4, 4.8 and 9.6 x 108 CFU g-1). We evaluated the germination and the sanity of seeds, length of seedling radicles, and production of indole acetic acid (IAA) by fungi. The experimental design was completely randomized in all experiments. In general, there was a predominance of Fusarium spp. and Rhizoctonia solani. The treatment of seeds with the conidia of Trichoderma sp. was positive for the parameters related to germination and radicle length of cowpea beans up to the concentration 4.8 x 108 CFU g-1. We conclude that the application of Trichoderma sp. was efficient in reducing the incidence of Fusarium spp., and promoted the germination and elongation of the radicle in cowpea

Antracnose foliar e produtividade de sorgo cultivado em áreas de várzea tropical e terras altas

O sorgo é o quinto cereal mais produzido no mundo e um fator limitante à sua produção é a incidência de doenças, tais como a antracnose (Colletotrichum graminicola). Este trabalho teve por objetivo avaliar a incidência e o progresso da antracnose e a produtividade de diferentes genótipos de sorgo em condições de várzea tropical e terras altas. Para tal, foram utilizados três genótipos de sorgo: DOW 1F305, A9735R e BRS 310. Aos 30 dias após o plantio (DAP), o experimento foi implantado com a aplicação da adubação de cobertura (40 e 80 kg ha-1 de nitrogênio). A avaliação da severidade da antracnose foi realizada utilizando uma escala de notas. Na coleta, determinou-se a produtividade dos genótipos com base na massa dos grãos. Foram registrados diferentes padrões de progresso da antracnose nos genótipos avaliados quando comparadas as duas áreas de estudo. Houve diferença na produtividade de grãos em resposta às doses de nitrogênio aplicadas. A suscetibilidade do genótipo BRS 310 pode estar associada principalmente às condições de cultivo, tendo em vista sua maior sensibilidade à antracnose foliar quando cultivado em terras altas. O genótipo DOW 1F305 foi menos sensível à antracnose e apresentou menor produtividade de grãos independente da condição de cultivo

Macro and Micro-Nutrient Accumulation and Partitioning in Soybean Affected by Water and Nitrogen Supply

This study aimed to investigate the influence of water availability and nitrogen fertilization on plant growth, nutrient dynamics, and variables related to soybean crop yield. Trials were performed in Teresina, Piauí, Brazil, using randomized blocks in a split-split plot arrangement. The plots corresponded to water regimes (full and deficient), the split plots to N fertilization (0 and 1000 kg ha-1 N-urea), and the split-split plots to harvest times of soybean plants (16, 23, 30, 37, 44, 58, 65, 79 and 86 days after emergence), with three replicates. In general, the accumulation and partitioning of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulphur (S), copper (Cu), iron (Fe), manganese (Mn), zinc (Zn) and boron (B) were decreased in plants subjected to water deficit and without N fertilization. Although nitrogen fertilization promoted elevated N accumulation in tissues, it did not result in any significant yield gain, and the highest seed yields were found in plants under full irrigation, regardless of N supplementation. However, deficient irrigation decreased the seed oil content of N-fertilized plants. In conclusion, N fertilization is critical for nutrient homeostasis, and water availability impairs biomass and nutrient accumulation, thereby limiting soybean yield performance

Interrelação Bradyrhizobium - BPCP’s - caupi : avaliação da atividade enzimática e performance simbiótica

Para o incremento da fixação biológica do nitrogênio (FBN) tem sido recorrente o uso de bactérias promotoras de crescimento em plantas (BPCP’s) em associação com o sistema simbiótico leguminosa-rizóbio. Desta forma, a busca da utilização de veículos alternativos que aumentem a qualidade e eficiência do inoculante levando a redução de custos e de possíveis impactos ambientais tem sido investigados. A FBN varia em resposta a fatores biológicos e ambientais e a sua efetividade pode ser mensurada através das concentrações dos compostos envolvidos neste processo, sendo um ponto relevante avaliar indicadores bioquímicos relacionados aos metabolismos do nitrogênio, do carbono e antioxidativo. Neste contexto, este trabalho teve como objetivos verificar a sobrevivência do caupi à colonização bacteriana, assim como avaliar a interrelação Bradyrhizobium sp. e BPCP’s visando uma melhor performance simbiótica e desenvolvimento do caupi; otimizar a FBN e o desenvolvimento do caupi, inoculados e co-inoculados com Bradyrhizobium sp. e BPCP’s, assim como avaliar as atividades de enzimas como indicadores de eficiência, senescência e de estresse/proteção oxidativo durante a após o estabelecimento da simbiose; e determinar a eficiência da inoculação e co-inoculação do caupi com Bradyrhizobium sp. e BPCP’s utilizando variáveis de crescimento e produção e, juntantemente, caracterizar o exopolissacarídeo utilizado como veículo de inoculação das sementes. Foram conduzidos três experimentos em casa de vegetação do Instituto Agronômico de Pernambuco (IPA). A leguminosa utilizada foi caupi cv. “IPA 206” inoculada com Bradyrhizobium sp. (BR 3267) e co-inoculadas com diferentes estirpes de BPCP’s. No experimento I, o delineamento experimental utilizado foi em blocos ao acaso com 24 tratamentos, sendo um com inoculação (BR 3267); 22 combinações (BR 3267 + BPCP’s); uma testemunha absoluta (TA), com três repetições. No experimento II, o delineamento experimental adotado foi em blocos ao acaso com arranjo fatorial 2x4, dois períodos de coleta (PF, ponto de florescimento; IS, início de senescência) e quatro tratamentos (inoculados e co-inoculados) + TA, com quatro repetições. No experimento III, o delineamento experimental utilizado foi em blocos ao acaso com arranjo fatorial 2x6, dois períodos de colheita (PF, ponto de florescimento; e EG, enchimento de grãos) e seis tratamentos, sendo um com inoculação (BR 3267), e três com co-inoculações (BR 3267 + BPCP’s); e duas testemunhas (TA e TN), com quatro repetições. Nos resultados constatou-se sinergismo entre BR 3267 e BPCP’s em caupi principalmente na combinação de BR 3267 com Paenibacillus graminis (MC 04.21) e P. durus (C 04.50), que exibiram melhor resposta simbiótica. As estirpes de BPCP’s pré-selecionadas foram combinadas com BR 3267, formando dois pares simbióticos (BR 3267 + MC 04.21; BR 3267 + C 04.50) e uma tripartite (BR 3267+ MC 04.21 + C 04.50) onde os resultados mostraram diferenças significativas para as variáveis de crescimento bem como para os indicadores bioquímicos relacionados aos metabolismos do nitrogênio, carbono e antioxidativo. Houve aumento da concentração de proteínas solúveis totais nos nódulos das plantas co-inoculadas em relação àquelas inoculadas isoladamente com a BR 3267. Ocorreu intensa atividade proteolítica e declínio na atividade das enzimas no IS, porém na co-inoculação tripartite houve retardo dos efeitos deletérios da senescência, o que permitiu uma melhor performance simbiótica na plantas de caupi. Pode-se sugerir o uso de inoculantes compostos com as bactérias estudadas visando incrementar a FBN e retardar a senescência dos nódulos assegurando a disponibilidade de nitrogênio por um maior período de tempo. Esta resposta ressalta a importância da combinação e compatibilidade de microrganismos introduzidos, em mistura, para promover uma melhor eficiência simbiótica do caupi, em especial para a co-inoculação em tripartite, com relação ao rizóbio nativo do solo, e esta resposta sinérgica resultou em melhoria nas variáveis de produção e eficiência da fixação de N2. Em relação às características químicas e reológicas do EPS, utilizado como veículo para inoculação, este se apresenta como um heteropolissacarídeo polianiônico com fluido pseudoplástico pouco viscoso, revelando-se pela técnica de calorimetria exploratória diferencial um pico endotérmico que representa uma característica favorável tendo em vista a possibilidade de seu uso em escala industrial.It has been a recurrent the use of plant growth-promoting bacteria (PGPB) in association with the legume-rhizobia symbiotic system to increase the biological nitrogen fixation (BNF). Thus, the search for using alternative vehicles that increase quality and efficiency of inoculum leading to reduced costs and possible environmental impacts have been investigated. The BNF change in response to biological and environmental factors and their effectiveness can be measured by the concentrations of compounds involved in this process, being an important point to evaluate biochemical indicators related to the metabolisms of nitrogen, carbon and antioxidant. In this context, this study aimed at verifying the survival of cowpea to bacterial colonization and evaluating the interrelationship of Bradyrhizobium sp. and PGPB providing better symbiotic performance and cowpea development; optimizing the BNF and cowpea development, inoculated and co-inoculated with Bradyrhizobium sp. and PGPB, as well as evaluating the activities of enzymes as indicators of efficiency, senescence and stress/oxidative protection during and after the establishment of symbiosis; and determining the efficiency of inoculation and co-inoculation of cowpea with Bradyrhizobium sp. and PGPB using variables of growth and production and, jointly, characterizing the exopolysaccharide used as a vehicle for seed inoculation. Three experiments were conducted in greenhouse of the Agronomy Institute of Pernambuco (IPA). The legume used was cowpea cv. "IPA 206" inoculated with Bradyrhizobium sp. (BR 3267) and co-inoculated with different strains of PGPB. In the first experiment, the experimental design was randomized blocks with 24 treatments one inoculated (BR 3267), and 22 co-inoculated (BR 3267 + PGPB); and an absolute control (AC), with three replications. In the experiment II, the experimental design was randomized blocks with 2x4 factorial arrangement, two harvest periods (FP, flowering point; BS, beginning of senescence) and four treatments (inoculated and co-inoculated) + AC, with four repetitions. In the experiment III, the experimental design was a randomized block with 2x6 factorial arrangement, two harvest periods (FP, flowering point; GF, grain filling) and six treatments, one inoculated (BR 3267), and three co-inoculated (BR 3267 + PGPB), and two controls (AC and NC), with four replications. In the results was found synergism between BR 3267 and PGPB in cowpea especially in combination of BR 3267 with strains Paenibacillus graminis (MC 04.21) and P. durus (C 04.50), which exhibited better symbiotic response. Pre-selected strains of PGPB were combined with BR 3267, forming two symbiotic pairs (BR 3267 + MC 04.21; BR 3267 + C 04.50) and a tripartite (BR 3267 + MC 4.21 + C 04.50) where the results showed significant differences for growth variables as well as the biochemical indicators related to the metabolisms of nitrogen, carbon and antioxidative. There was increased concentration of total soluble proteins in nodules of plants co-inoculated compared to those inoculated in isolation with BR 3267. There was intense proteolytic activity and a decline in enzyme activity in the BS, but there was delayed of the deleterious effects of aging in the tripartite co-inoculation, allowing better symbiotic performance in cowpea plants. It can be suggested the use of inoculating compounds with bacteria studied aiming at improving the BNF and delaying senescence of nodules ensuring the availability of nitrogen for a longer period of time. This response emphasizes the importance of the combination and compatibility of microorganisms introduced, in combination, to promote a better symbiotic efficiency of cowpea, especially for tripartite co-inoculation, with respect to Rhizobium native to soil, and this synergistic response resulted in improved variables of production and efficiency of N2 fixation. With respect to chemical and rheological characteristics, the EPS used as vehicle for inoculation presents as a polyanionic heteropolysaccharide with low-viscosity fluid pseudoplastic, revealing an endothremal peak by the technique of differential scanning calorimetry that represents a favorable feature considering its use on industrial scale.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESConselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNP

Triassic Reservoir potential in the greater Oda and Ula fields area, North Sea

Master's thesis in Petroleum Geosciences EngineeringThe objective of this thesis is to improve the understanding of the lateral distribution of the sandstones of the Skagerrak Fm, by using 3D seismic data and wells in the greater Oda and Ula field area. The Oda and Ula fields are located in the salt province in the Central Graben. Consequently, salt tectonics played an important role in the deposition of the Skagerrak Fm sands, resulting in a large lateral variation in thickness and facies. The composition of the salt also has a large impact on the supra-salt structural style, and furthermore the sedimentation of the Skagerrak Fm. The interaction between salt tectonics and sedimentation is investigated in order to understand how salt related subsidence or uplift acted as depocenters for sedimentation. The main aim is to understand the facies distribution, to further build a conceptual model for sandstone fairways, and ultimately point to areas where there can be good quality reservoir potential in the Triassic. Most wells in the salt province are placed in an interpod setting where the Skagerrak Fm is very thin or absent, since it has not traditionally been the main target. However, it is a proven working play, and is being produced in the Ula Field. It is therefore likely that there are commercial accumulations of oil other places as well in the Triassic section in the area. Two different salt regimes has been defined, where one salt unit is mobile and halite-dominated. The other salt unit is interbedded with carbonates and anhydrite, and consequently a lot more viscous and non-mobile. The two salt regimes result in different subsalt structural style. The mobile salt unit result in a pod-area where accommodation space is created next to large salt structures, where the Skagerrak Fm sandstone can be deposited and preserved. In contrast, in the area of the non-mobile unit the Triassic thickness is relatively constant and the Top Triassic surface has a gentle topography. The Skagerrak Fm is a part of a regional fluvial alluvial system, and is locally interpreted to be in a braided streams depositional environment with ephemeral lakes. Rivers have been directed into the pods, where there has been accommodation space for sediments to be deposited, and it is suggested that there is a good Triassic reservoir potential within the pods. The interpod area is farther away from the channel feeder, well logs show less developed sand packages and has possibly lower reservoir potential

Severidade de antracnose em folhas de sorgo submetido a doses crescentes de silício

A antracnose foliar é causada pelo fungo Colletotrichum sublineolum Hann. Kabát et Bub. (sin. C. graminicola (Ces.) G.W. Wils.) em plantas de sorgo podendo reduzir a produtividade de grãos e forragem, e o manejo adequado da nutrição mineral desta planta pode se apresentar como um mecanismo de controle sobre a antracnose. Dentre os minerais utilizados para o manejo de doenças, o silício destaca-se por reduzir a severidade das doenças em várias culturas. Diante do exposto, este trabalho teve por objetivo avaliar a severidade da antracnose em diferentes genótipos de sorgo suplementados com doses crescentes de silício. Para tal, realizaram-se experimentos em condições de casa de vegetação e de campo onde os genótipos de sorgo DOW 1F305 e A9735R foram suplementados com doses crescentes de silício (0; 500; 1.000; 1.500; 2.000; e 4.000 kg ha-1) e avaliados quanto à severidade da antracnose. Avaliou-se a severidade da doença por meio de uma escala de notas e, em seguida, amostras foram coletadas para determinação da concentração de silício nas folhas. Após a análise dos resultados, concluiu-se que houve redução na severidade da antracnose em resposta a adubação com silício para ambos os genótipos avaliados. Apesar do genótipo de sorgo DOW 1F305 acumular menores teores de silício em suas folhas, este genótipo foi mais resistente ao ataque da antracnose foliar

Efficiency of application of Trichoderma on the physiological quality and health of cowpea seeds

One of the main causes of low productivity of cowpea crops in Brazil is the use of low quality seeds. Low quality seeds have a high degree of infestation by phytopathogens, mainly fungi. Seed treatment with biological control agents, such as fungi of the genus Trichoderma, is a useful alternative to reduce or inhibit the transmission of diseases via seeds. In view of the above, this study aims to evaluate the physiological and sanitary quality of cowpea seeds treated with conidia of Trichoderma sp. (1.2, 2.4, 4.8 and 9.6 x 108 CFU g-1). We evaluated the germination and the sanity of seeds, length of seedling radicles, and production of indole acetic acid (IAA) by fungi. The experimental design was completely randomized in all experiments. In general, there was a predominance of Fusarium spp. and Rhizoctonia solani. The treatment of seeds with the conidia of Trichoderma sp. was positive for the parameters related to germination and radicle length of cowpea beans up to the concentration 4.8 x 108 CFU g-1. We conclude that the application of Trichoderma sp. was efficient in reducing the incidence of Fusarium spp., and promoted the germination and elongation of the radicle in cowpea

Respostas antioxidativas em nódulos de caupi inoculado com bradyrhizobium

O nitrogênio é considerado elemento essencial para as plantas, pois está presente na composição das mais importantes biomoléculas. As plantas podem obter esse nitrogênio através do processo de fixação biológica pela simbiose entre a planta e as bactérias fixadoras de nitrogênio. A fixação biológica do nitrogênio pode ser afetada por fatores bióticos e abióticos que provocam estresse oxidativo na planta. O sistema antioxidativo enzimático envolve enzimas, como por exemplo dismutase de superóxido (SOD), catalase (CAT), peroxidase de fenóis (POX), que conferem proteção oxidativa às plantas. Desta forma, objetivo deste trabalho foi avaliar o metabolismo antioxidativo em nódulos de plantas de feijão-caupi inoculadas com Bradyrhizobium sp. (estirpe BR 3267). Os resultados mostraram que a inoculação com Bradyrhizobiumsp. foi efetiva e resultou em baixo acúmulo de amônia e diminuição do estresse oxidativo. Concluiu-se que a inoculação de caupi comBradyrhizobium sp. foi efetiva em estimular as enzimas envolvidas no processo oxidativo (SOD, POX e CAT). Estas enzimas foram eficientes na remoção das espécies reativas de oxigênio e promoveram proteção oxidativa para plantas de caupi.  

FERTILIZAÇÃO SILICATADA E NITROGENADA NO CONTROLE DA BRUSONE DO ARROZ EM SISTEMA IRRIGADO

The silicon fertilization has a beneficial effect in enhancing the resistance of plants to diseases, however, this effect can be reduced in the presence of high levels of nitrogen. Given the above, this study aimed to investigate the effect of silicated and nitrogen fertilization in control of rice blast in irrigated system. Plants were grown in an area of tropical lowland and evaluated as to the severity of leaf blast incidence on pan-1 of calcium and magnesium silicate associated with 45 kg ha - 1 of nitrogen topdressing on had lower severity of leaf blast and higher grain yield compared to plants not supplemented with silicon. The combination of silicated fertilization with 90 kg ha - 1 of nitrogen topdressing resulted in a greater incidence of panicle rice blast. After analyzing the results, it was concluded that supple- mentation with silicon and nitrogen promoted reduction in the severity of blast in rice plants in irrigation sys- tem without affecting the yield