623 resultados para CUCUMIS-SATIVUS


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This paper highlights the potential benefits of smoke recovery from the production of biochar in crop management through it application as an antimicrobial agent against plant disease and as a pesticide. The study reports on the findings of zone inhibition assays on selected plant pathogens (Agrobacterium tumefacien and Xanthomonas campestris), growth studies on selected plants (Raphanus sativus and Vicia faba), and toxicity studies performed on arthropods (Myzus persicae and Tetranychus urticae). The results suggested a strong benefit to crop management in terms of crop protection against selected causal agents responsible for plant disease, with zones of inhibition observed on both Agrobacterium tumefacien and Xanthomonas campestris when inoculated with pyroligneous acid (liquid smoke) at 10% dilution. Similarly, its potential as a bio-pesticide are favorable, with a reported 20%–30% of arthropods affected (knocked out/mortality) after exposure for 48 hours.

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This paper marks the first in a series of studies into the potential use of pyrolysis products in the development of more sustainable practices within the agricultural industry. In this study, the immediate benefits of the application of biochar to crop yields of Raphanus sativus (radishes) are assessed. Furthermore, the study reports on the preliminary findings into the potential application of pyroligneous acid (wood vinegar) as a biocidal agent against crop disease. Although germination tests undertaken on biochar/compost blends of up to 1: 2, by weight, showed no significant adverse effect from the addition of the nutrient rich carbonaceous solid, evidence of substantial increases in crop yield through the addition of biochar were not observed. In sharp contrast, zones of inhibition were observed at 3-10 vol. % upon application of pyroligneous acid to two causal agents responsible for certain diseases in vegetable and fruit crops, i.e. Rhizobium radiobacter (agrobacterium tumefaciens) and Xanthomonas campestris, highlighting the versatility in the application of pyrolysis products and avenues for exploration in the development of this biomass conversion technology.

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Glacial-interglacial fluctuations in the vegetation of South Africa might elucidate the climate system at the edge of the tropics between the Indian and Atlantic Oceans. However, vegetation records covering a full glacial cycle have only been published from the eastern South Atlantic. We present a pollen record of the marine core MD96-2048 retrieved by the Marion Dufresne from the Indian Ocean ~120 km south of the Limpopo River mouth. The sedimentation at the site is slow and continuous. The upper 6 m (spanning the past 342 Ka) have been analysed for pollen and spores at millennial resolution. The terrestrial pollen assemblages indicate that during interglacials, the vegetation of eastern South Africa and southern Mozambique largely consisted of evergreen and deciduous forests. During glacials open mountainous scrubland dominated. Montane forest with Podocarpus extended during humid periods was favoured by strong local insolation. Correlation with the sea surface temperature record of the same core indicates that the extension of mountainous scrubland primarily depends on sea surface temperatures of the Agulhas Current. Our record corroborates terrestrial evidence of the extension of open mountainous scrubland (including fynbos-like species of the high-altitude Grassland biome) for the last glacial as well as for other glacial periods of the past 300 Ka.

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To better understand Holocene vegetation and hydrological changes in South Africa, we analyzed pollen and microcharcoal records of two marine sites GeoB8331 and GeoB8323 from the Namaqualand mudbelt offshore the west coast of South Africa covering the last 9900 and 2200 years, respectively. Our data corroborate findings from literature that climate developments apparently contrast between the summer rainfall zone (SRZ) and winter rainfall zone (WRZ) over the last 9900 years, especially during the early and middle Holocene. During the early Holocene (9900-7800 cal.yr BP), a minimum of grass pollen suggests low summer rainfall in the SRZ, and the initial presence of Renosterveld vegetation indicates relatively wet conditions in the WRZ. Towards the middle Holocene (7800-2400 cal. yr BP), a rather moist savanna/grassland rich in grasses suggests higher summer rainfall in the SRZ resulting from increased austral summer insolation and a decline of fynbos vegetation accompanied by an increasing Succulent Karoo vegetation in the WRZ possibly suggests a southward shift of the Southern Hemisphere westerlies. During the last 2200 years, a trend towards higher aridity was observed for the SRZ, while the climate in the WRZ remained relatively stable. The Little Ice Age (ca. 700-200 cal. yr BP) was rather cool in both rainfall zones and drier in the SRZ while wetter in the WRZ.

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La berenjena (Solanum melongena L.) es una planta solanácea de múltiples variedades, cuyos ancestros salvajes se sitúan en Indochina y el este de África. Su cultivo fue muy temprano en zonas de China e India. Aun así, no se extendió al Occidente antiguo ni apenas se conoció, de ahí su ausencia en los textos clásicos de botánica y farmacología. Fueron los árabes quienes llevaron el cultivo de la planta por el Norte de África y Al-Andalus, de donde pasó ya a Europa. Los primeros testimonios occidentales de la berenjena aparecen en traducciones latinas de textos árabes, para incorporarse luego a la literatura farmacológica medieval y, más tarde ya, a la del Renacimiento, que empezó a tratar de ella por su posible parecido con una especie de mandrágora. Pese a que se le reconocían algunas virtudes medicinales, siempre se la tuvo bajo sospecha por ser de sabor poco agradable, indigesta y causante de algunas afecciones. Solo los botánicos de finales del Renacimiento describirían la planta y sus variedades con criterios más «científicos» y botánicos, ya sin apenas intereses farmacológicos.

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The auxin receptor ABP1 directly regulates plasma membrane activities including the number of PIN-formed (PIN) proteins and auxin efflux transport. Red light (R) mediated by phytochromes regulates the steady-state level of ABP1 and auxin-inducible growth capacity in etiolated tissues but, until now, there has been no genetic proof that ABP1 and phytochrome regulation of elongation share a common mechanism for organ elongation. In far red (FR)-enriched light, hypocotyl lengths were larger in the abp1-5 and abp1/ABP1 mutants, but not in tir1-1, a null mutant of the TRANSPORT-INHIBITOR-RESPONSE1 auxin receptor. The polar auxin transport inhibitor naphthylphthalamic acid (NPA) decreased elongation in the low R: FR light-enriched white light (WL) condition more strongly than in the high red: FR light-enriched condition WL suggesting that auxin transport is an important condition for FR-induced elongation. The addition of NPA to hypocotyls grown in R-and FR-enriched light inhibited hypocotyl gravitropism to a greater extent in both abp1 mutants and in phyB-9 and phyA-211 than the wild-type hypocotyl, arguing for decreased phytochrome action in conjunction with auxin transport in abp1 mutants. Transcription of FR-enriched light-induced genes, including several genes regulated by auxin and shade, was reduced 3-5-fold in abp1-5 compared with Col and was very low in abp1/ABP1. In the phyB-9 mutant the expression of these reporter genes was 5-15-fold lower than in Col. In tir1-1 and the phyA-211 mutants shade-induced gene expression was greatly attenuated. Thus, ABP1 directly or indirectly participates in auxin and light signalling.

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Este artículo informa sobre la valoración de la fitotóxicidad del Material Particulado Sedimentable (MPS) en la zona urbana del cantón Cuenca. El MPS se recolectó en tres sitios de la zona urbana, mediante el método descrito en el Texto Unificado de Legislación Ambiental Secundaria del Ministerio del Ambiente (TULASMA). Por el material particulado se realizó la determinación de la concentración de los componentes utilizando el análisis gravimétrico, la de los metales pesados por espectroscopía de absorción atómica, y la de aniones por método adaptado de referencia EPA 300.1. Posteriormente se evaluó su fitotóxicidad en cuatro especies, mediante el bioensayo de germinación y elongación de raíz e hipocótilo, en semillas de Lactuca sativa, Brassica oleracea itálica, Allium cepa y Raphanus sativus. En el bioensayo las semillas se expusieron a diferentes diluciones de la suspensión acuosa de MPS. Los resultados muestran que el efecto de los MPS dependió de la concentración y de la especie analizada, evidenciando diferentes grados de fitotóxicidad.

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Avaliaram-se a germinação e o vigor de sementes de melão (Cucumis melo L.), sob condicoes de ripado, utilizando-se solos com diferentes concentrações salinas. Observou-se que a germinação das sementes manteve-se inalterada ate o nível de 6,27 mmho/cm de condutividade elétrica, enquanto o seu vigor foi afetado por níveis inferiores. Níveis mais altos de salinidade exerceram efeitos bem pronunciados na germinação ao nível de CE 25oC= 9,46 mmho/cm, uma redução superior a 50% e no vigor, uma drástica redução.

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Tese de dout. em Ciências Agrárias, especialidade Protecção de Plantas, Faculdade de Engenharia e Recursos Naturais, Univ. do Algarve, 2001

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This paper presents the results of four field experiments carried out with the objetive of evaluating the feaibility of irrigation by porous capsule method, from 1979 to 1983, at Bebedouro Experiment Station, EMBRAPA-CPATSA, Petrolina, PE, Brazil. The irrigation system consisted of fulcrum of cone shaped porous capsules, interconnected with conduit pipe and installed in the soil at equidistance and 0.10 m deep along contour lines. The hydrostatic pressures studies did not significantly influence the crop yield, but influenced, at 0.10 level, the daily water release from porous unit. The mean yields for watermelon (Citrullus vulgaris Shard), var. Charleston Gray, for muskmelon (Cucumis melo L.) var. Valenciano Amarelo, and for maize (Zea mays L.), var. Centralmex, estimated in ton/2,500 units/ha or in cobs/2,500 units/ha, were 28.5, 10 and 17,500, respectively. The water consumption for watermelon, musk melon and maize was, respectively, 60 mm, 60 mm and 100 mm in a deep sandy yellow-red latosol. The cost of the system was US$ 1.677,41/ha.

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Tillage systems strongly affect nutrient transformations and plant availability. The objective of this study was to assess the nitrate dynamic in soil solution in different tillage systems with use of plant cocktail as green manure in fertilized melon (Cucumis melon) in Brazilian semi-arid. The treatments were arranged in four blocks in a split-plot design and included three types of cover crops and two tillage systems, conventional tillage (CT) and no-till (NT). The data showed no strong effect of plant cocktails composition on NO3-N dynamic in the soil. Mean concentration of NO3-N ranged from 19.45 mg L-1 at 15 cm to 60.16 mg L-1 at 50 cm soil depth, indicating high leachability. No significant differences were observed between NT and CT treatments for 15 cm depth. The high soil moisture content at ~ 30 cm depth concentrated high NO3-N in all treatments, mean of 54.27 mg L-1 to NT and 54.62 mg L-1 to CT. The highest NO3-N concentration was observed at 50 cm depth in TC (60.16 mg L-1). High concentration of NO3-N in CT may be attributed to increase in decomposition of soil organic matter and crop residues incorporated into the soil.

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O presente estudo teve como objetivo avaliar o comportamento forrageador de A. mellifera para a coleta de néctar nas flores de meloeiro do tipo amarelo (Cucumis melo Lineu, 1753) ao longo do ano, sem adição de colmeias.

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The objective of this work was to evaluate the biological variables of Spodoptera frugiperda on species of cover crops. The experiments were conducted in laboratory and greenhouse using the following species: sunflower (Helianthus annuus), sun hemp (Crotalaria juncea), brachiaria (Urochloa decumbens e Urochloa ruziziensis), millet (Pennisetum americanum), black oat (Avena stringosa), white lupin (Lupinus albus), forage turnip (Rafanus sativus) and maize (Zea mays). In laboratory the S. frugiperda larval survival varied from 57%, on L. albus, to 93% on H. annuus and the survival of the pre-imaginal phase varied from 45% on U. decumbens to 81.6% on Z. mays. On C. juncea the larval biomass was lower and the development period of the young and larval stage was higher. The adaptation index was less on C. juncea in greenhouse and laboratory. In greenhouse the larval survival at 14 days was similar for all plants and at 21 days was the lowest on C. juncea. There was less accumulation of biomass at 14 days on C. juncea and at 21 days on C. juncea and A. stringosa. Regarding damage, C. juncea presented less susceptibility to Spodoptera frugiperda attack, which together with the other evaluated parameters, indicated this plant as the most appropriate for soil cover before cultivation of maize.

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Dissertação (mestrado)—Universidade de Brasília, Departamento de Botânica, Programa de Pós-Graduação em Botânica, 2015.

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Este experimento foi realizado no Campo Experimental de Bebedouro, da Embrapa Semi-Árido, em Petrolina-PE, de janeiro de 1999 a dezembro de 2001, num Argissolo Amarelo eutrófico textura arenosa, com o objetivo de avaliar o efeito de adubos verdes associados à calagem e adubação mineral e orgânica nos atributos químicos do solo e na produtividade e qualidade do melão (Cucumis melo) irrigado. O delineamento experimental foi de blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. Os tratamentos alocados nas parcelas constituíram-se dos adubos verdes: (1) milho (Zea mays) com retirada da palhada do local, como testemunha (MI); (2) mucuna-preta (Mucuna aterrima) (MP); (3) milho + caupi (Vigna unguiculata) (MC); e (4) adubos verdes diferentes em cada ano: dois cultivos sucessivos de crotalária (Crotalaria juncea) no primeiro ano, milheto (Pennisetum glaucum) + caupi no segundo e crotalária + caupi no terceiro (RA). Nas subparcelas, os tratamentos corresponderam a: dose completa de calagem e adubação mineral e orgânica conforme a análise do solo (DC); e metade da dose do tratamento anterior (MD). Os cultivos dos adubos verdes foram realizados no primeiro semestre, seguidos do cultivo do melão no segundo. Todos os adubos verdes proporcionaram aumentos nos valores de Ca e da CTC do solo nas camadas de 0?10 cm e 10?20 cm em relação à testemunha (MI), com exceção da MP para CTC na primeira profundidade. Na camada de 0?10 cm, houve aumento também nos teores de K e matéria orgânica do solo, exceto nos teores de K do MC. Em 2001, ano em que o meloeiro atingiu a maior produtividade, o adubo verde RA proporcionou maior rendimento de melão que o adubo MP e a testemunha. Da mesma forma, o tratamento DC promoveu maior produtividade que o MD. Nesse mesmo ano, os teores de sólidos solúveis totais dos frutos foram mais elevados no tratamento com MP que na testemunha.