Processing and modelling of seismic reflection data acquired off the Durham coast

Off the Durham coast, the Permian succession above the Coal Measures contains limestones and anhydrite bands with high seismic velocities and reflection coefficients. The consequent reduction in penetration of seismic energy makes it difficult to determine Coal Measures structure by the seismic reflection method. Seismic data sets acquired from this region by the National Coal Board in 1979 and 1982 are used to illustrate that satisfactory results are difficult to achieve. Synthetic seismograms, generated for a simplified geological section of the region, are also used to study various aspects of the overall problem of applying the seismic technique in the area. Standard and non-standard processing sequences are applied to the seismic data to enhance the quality of the stacked sections and the results are discussed. This processing showed that in the 1979 survey, in which a watergun source and a 600m streamer were used, some penetration was achieved but Coal Measures resolution on the final sections is poor. The 1982 data set, shot along a segment of the 1979 line using a sleeve exploder source and a 150m streamer, showed no Coal Measures after processing. Synthetic seismograms, generated using the reflectivity method and a broadband source wavelet, are processed to confirm that a streamer with a length of 360 to 400m towed at a depth of 5-7.5m will be optimal for future data acquisition in the area. It is also shown that the erosion of the surface of the limestone lowers the horizontal resolution of the Coal Measures. Scatterin

Componentes de produção como indicadores de tolerância à seca em cana-de-açúcar

A deficiência de água é um dos principais fatores que limitam a produção da cana-de-açúcar (Saccharum officinarum L.). Estudar os efeitos do estresse hídrico sobre os componentes de produção e sua relação com a produtividade pode ajudar os programas de melhoramento a selecionar genótipos produtivos sob essa condição. O objetivo deste estudo foi investigar as relações entre os caracteres número de colmos, altura de colmos, diâmetro de colmos e massa de colmos com a produtividade de cana-de-açúcar cultivada em uma área, sob deficiência moderada de água, durante o período de maior desenvolvimento, a fim de prover informações que auxiliem melhoristas na adoção de características para selecionar variedades tolerantes à seca. Foram cultivados 78 genótipos e dois padrões, um tolerante e outro sensível ao estresse hídrico, sob deficiência moderada de água em campo e durante o ano agrícola 2005/2006 em Weslaco, Texas, Estados Unidos. Produtividade e os componentes de produção foram avaliados. Sob estresse, o padrão tolerante (TCP93-4245) apresentou maior produtividade, número de colmos, altura de colmos e massa de colmos do que o padrão sensível (TCP87-3388). Entretanto, o padrão sensível apresentou maior diâmetro de colmos. Associação linear foi encontrada entre produtividade e seus componentes, mas diâmetro de colmos foi bastante instável entre os genótipos. Altura de colmos apresentou correlação positiva com número, diâmetro e massa de colmos. Diâmetro de colmos também apresentou correlação positiva com massa de colmos. Portanto, durante o processo de seleção, quando um desses componentes é melhorado para tolerância à seca, o componente correlacionado deverá também ser melhorado, tornando-se possível selecionar genótipos com elevada produtividade e número, altura e massa de colmos sob deficiência hídrica.Water deficit is one of the major factors limiting the production of sugarcane (Saccharum officinarum L.). A study of the effects of limited water condition on yield components and their relationship with productivity can aid breeding programs in selecting for high yielding genotypes under this condition. The objective of this study was to investigate the relationships among the parameters stalk number, stalk height, stalk diameter, and stalk weight with cane yield in sugarcane growing in a field under moderate water stress during its grand growth period, in order to provide information to help breeders in adopting traits for selecting drought tolerant varieties. Seventy-eight genotypes plus two controls, one drought-tolerant and one drought-susceptible, were grown under a moderate water deficit condition in the field in 2005/2006 at Weslaco, TX. Productivity and yield components were measured. Under stress, the tolerant control (TCP93-4245) showed higher productivity, stalk number, stalk height and stalk weight than the susceptible one (TCP87-3388). However, the susceptible control showed higher stalk diameter. Linear association was found between productivity and its yield components, but stalk diameter showed to be fairly unstable among genotypes. Stalk height showed significant correlation with stalk number, stalk diameter and stalk weight. Stalk diameter also showed positive correlation with stalk weight. Therefore, during the selection procedure, when one of these traits is enhanced by drought tolerance, the correlated trait should also increase, making it feasible to select genotypes with high productivity, stalk number, stalk height, and stalk weight under water deficit

Responses of Jatropha curcas

Two greenhouse experiments were conducted to quantify growth responses of Jatropha curcas to a range of salt and drought stresses. Typical symptoms of salinity stress such as leaf edge yellowing were observed in all elevated salinity treatments and the degree of the foliar salt damage increased with the salinity of irrigation water. Total dry weight (DW) of Jatropha plants was reduced by 30%, 30%, and 50%, respectively, when irrigated with saline solutions at electrical conductivity of 3.0, 6.0, and 9.0 dS m−1 compared to that in the control. Leaf Na+ concentration was much higher than that observed in most glycophytes. Leaf Cl− concentrations were also high. In the drought stress experiment, plants were irrigated daily with nutrient solution at 100%, 70%, 50%, or 30% daily water use (DWU). Deficit irrigation reduced plant growth and leaf development. The DW of leaves, roots, and total were reduced in the 70%, 50%, and 30% DWU compared to the 100% DWU control treatment. In summary, salinity stress and deficit irrigation significantly reduced the growth and leaf development of greenhouse-grown Jatropha plants

Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year

[EN] The objective of this work was to study the influence of fruit load on CO2 assimilation in the leaves of citrus trees presenting alternate bearing habits, and the importance of this factor on photosynthetic rate variability throughout the year and under regular cropping conditions. The photosynthetic rate was measured on 60 days throughout the year on field-grown sweet orange plants under natural conditions in the Valencian Community, the most important citrus-producing area of Spain. The experiments were performed on the 'on' (high crop) and 'off' (low crop) bearing 40-year-old Salustiana sweet orange trees growing in the same orchard. Gas exchange and fluorescence parameters were measured during the year in young and old leaves on sun-exposed branches with and without fruit in the 'on' trees, and in fruitless branches of the 'off' trees. In non-manipulated Citrus trees, fruit load has no significant effect in any season on the photosynthetic rate in the leaves from branches without fruit. However, in high crop trees, the leaves of branches bearing fruit present a slightly lower photosynthetic rates (approx. 10%) than those of fruitless branches. Variations in mineral content (N, K and P) might explain not only these differences, but also the lower photosynthesis rate observed in old leaves (13-24 month-old leaves). Environmental conditions were the main factor for the variation of the photosynthetic rate, with variability of the monthly mean photosynthetic rate being much lower than that between days in the same month.González Nebauer, S.; Arenas, C.; Rodríguez Gamir, J.; Bordon, Y.; Fortunato Almeida, A.; Monerri Huguet, MC.; Guardiola Barcena, JL.... (2013). Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year. Scientia Horticulturae. 160:358-365. doi:10.1016/j.scienta.2013.06.008S35836516

Provitamin A biofortification of cassava enhances shelf life but reduces dry matter content of storage roots due to altered carbon partitioning into starch

Storage roots of cassava (Manihot esculenta Crantz), a major subsistence crop of sub-Saharan Africa, are calorie rich but deficient in essential micronutrients, including provitamin A β-carotene. In this study, β-carotene concentrations in cassava storage roots were enhanced by coexpression of transgenes for deoxy-d-xylulose-5-phosphate synthase (DXS) and bacterial phytoene synthase (crtB), mediated by the patatin-type 1 promoter. Storage roots harvested from field-grown plants accumulated carotenoids to ≤50 lg/g DW, 15- to 20-fold increases relative to roots from nontransgenic plants. Approximately 85%–90% of these carotenoids accumulated as all-trans-β-carotene, the most nutritionally efficacious carotenoid. β-Carotene-accumulating storage roots displayed delayed onset of postharvest physiological deterioration, a major constraint limiting utilization of cassava products. Large metabolite changes were detected in β-carotene-enhanced storage roots. Most significantly, an inverse correlation was observed between β-carotene and dry matter content, with reductions of 50%–60% of dry matter content in the highest carotenoid-accumulating storage roots of different cultivars. Further analysis confirmed a concomitant reduction in starch content and increased levels of total fatty acids, triacylglycerols, soluble sugars and abscisic acid. Potato engineered to co-express DXS and crtB displayed a similar correlation between β-carotene accumulation, reduced dry matter and starch content and elevated oil and soluble sugars in tubers. Transcriptome analyses revealed a reduced expression of genes involved in starch biosynthesis including ADP-glucose pyrophosphorylase genes in transgenic, carotene-accumulating cassava roots relative to nontransgenic roots. These findings highlight unintended metabolic consequences of provitamin A biofortification of starch-rich organs and point to strategies for redirecting metabolic flux to restore starch production

Spectral and thermal data as a proxy for leaf protective energy dissipation under kaolin application in grapevine cultivars

Research ArticleThe dynamic effects of kaolin clay particle film application on the temperature and spectral reflectance of leaves of two autochthonous cultivars (Touriga Nacional (TN, n=32) and Touriga Franca (TF, n=24)) were studied in the Douro wine region. The study was implemented in 2017, in conditions prone to multiple environmental stresses that include excessive light and temperature as well as water shortage. Light reflectance from kaolin-sprayed leaves was higher than the control (leaves without kaolin) on all dates. Kaolin’s protective effect over leaves’ temperatures was low on the 20 days after application and ceased about 60 days after its application. Differences between leaves with and without kaolin were explained by the normalized maximum leaf temperature (T_max_f_N), reflectance at 400 nm, 532 nm, and 737 nm, as assessed through TN data. The wavelengths of 532 nm and 737 nm are associated with plant physiological processes, which support the selection of these variables for assessing kaolin’s effects on leaves. The application of principal component analysis to the TF data, based on these four variables (T_max_f_N and reflectances: 400, 532, 737 nm) selected for TN, explained 83.56% of data variability (considering two principal components), obtaining a clear differentiation between leaves with and without kaolin. The T_max_f_N and the reflectance at 532 nm were the variables with a greater contribution for explaining data variability. The results improve the understanding of the vines’ response to kaolin throughout the grapevine cycle and support decisions about the re-application timinginfo:eu-repo/semantics/publishedVersio

Increasing atmospheric [CO2] from glacial through future levels affects drought tolerance via impacts on leaves, xylem and their integrated function

This is the peer reviewed version of the following article: Medeiros, J. S. and Ward, J. K. (2013), Increasing atmospheric [CO2] from glacial to future concentrations affects drought tolerance via impacts on leaves, xylem and their integrated function. New Phytol, 199: 738–748. doi:10.1111/nph.12318, which has been published in final form at http://doi.org/10.1111/nph.12318. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Changes in atmospheric carbon dioxide concentration ([CO2]) affect plant carbon/water trade-offs, with implications for drought tolerance. Leaf-level studies often indicate that drought tolerance may increase with rising [CO2], but integrated leaf and xylem responses are not well understood in this respect. In addition, the influence of low [CO2] of the last glacial period on drought tolerance and xylem properties is not well understood. We investigated the interactive effects of a broad range of [CO2] and plant water potentials on leaf function, xylem structure and function and the integration of leaf and xylem function in Phaseolus vulgaris. Elevated [CO2] decreased vessel implosion strength, reduced conduit specific hydraulic conductance, and compromised leaf specific xylem hydraulic conductance under moderate drought. By contrast, at glacial [CO2], transpiration was maintained under moderate drought via greater conduit specific and leaf specific hydraulic conductance in association with increased vessel implosion strength. Our study involving the integration of leaf and xylem responses suggests that increasing [CO2] does not improve drought tolerance. We show that under glacial conditions changes in leaf and xylem properties could increase drought tolerance, while under future conditions greater productivity may only occur when higher water use can be accommodated

Evaluation of ground-level and space-borne sensor as tools in monitoring nitrogen nutrition status in immature and mature oil palm

Monitoring nitrogen (N) in oil palm is crucial for the production sustainability. The objective of this study is to examine the capability of visible (Vis), near infrared (NIR) and a combination of Vis and NIR (Vis + NIR) spectral indices acquired from different sensors for predicting foliar N content of different palm age groups. The N treatments varied from 0 to 2 kg per palm, subjected according to immature, young mature and prime mature classes. The Vis + NIR indices from the ground level-sensor that is green + red + NIR (G + R + NIR) was the best index for predicting N for immature palms (R2 = 0.91), while Vis indices blue + red (B + R) and Green Red Index from the space-borne sensor were significantly useful for N assessment of young and prime mature palms (R2 = 0.70 and 0.50), respectively. The application of vegetation indices for monitoring N status of oil palm is beneficial to examine extensive plantation areas