Influence of Host Nitrogen Levels on Development, Survival, Size and Population-Dynamics of Sugarcane Mealybug, Saccharicoccus-Sacchari (Cockerell) (Hemiptera, Pseudococcidae)

1992 ◽  
Vol 40 (3) ◽  
pp. 327 ◽  
Author(s):  
DJ Rae ◽  
RE Jones
Keyword(s):  
Population Dynamics ◽  
Laboratory Experiments ◽  
Laboratory Data ◽  
Growing Season ◽  
Seasonal Effects ◽  
Detectable Effect ◽  
Soluble Nitrogen ◽  
Nitrogen Levels ◽  
Nitrogen Concentrations ◽  
Saccharicoccus Sacchari

Nitrogen levels in commercial plots of sugarcane varied over the cane-growing season. However, when adjusted for seasonal effects, nitrogen did not have a detectable effect on the size of mealybug populations on cane. In laboratory experiments, the survival of immature Saccharicoccus sacchari and the size attained at the onset of the oviposition period was influenced by the level of nitrogen fertiliser applied to potted sugarcane. Survival of S. sacchari increased to a maximum at 320 mg L-1 soluble nitrogen in sugarcane and decreased at higher levels, while size increased with increased nitrogen over the whole range of concentrations tested. Nitrogen-driven changes in the abundance of S. sacchari predicted from laboratory data indicate that normal variations in nitrogen concentrations of field-grown sugarcane have little effect on the population dynamics of S. sacchari.

scholarly journals Enhanced Autophagic Activity Improved the Root Growth and Nitrogen Utilization Ability of Apple Plants under Nitrogen Starvation

2021 ◽  
Vol 22 (15) ◽  
pp. 8085
Author(s):  
Liuqing Huo ◽  
Zijian Guo ◽  
Qi Wang ◽  
Li Cheng ◽  
Xin Jia ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Root Growth ◽  
Nitrogen Starvation ◽  
Degradation Pathway ◽  
Physiological Status ◽  
Hydroponic System ◽  
Nitrogen Levels ◽  
Nitrogen Concentrations ◽  
Nitrogen Nutrients ◽  
Autophagic Activity

Autophagy is a conserved degradation pathway for recycling damaged organelles and aberrant proteins, and its important roles in plant adaptation to nutrient starvation have been generally reported. Previous studies found that overexpression of autophagy-related (ATG) gene MdATG10 enhanced the autophagic activity in apple roots and promoted their salt tolerance. The MdATG10 expression was induced by nitrogen depletion condition in both leaves and roots of apple plants. This study aimed to investigate the differences in the growth and physiological status between wild type and MdATG10-overexpressing apple plants in response to nitrogen starvation. A hydroponic system containing different nitrogen levels was used. The study found that the reduction in growth and nitrogen concentrations in different tissues caused by nitrogen starvation was relieved by MdATG10 overexpression. Further studies demonstrated the increased root growth and the higher nitrogen absorption and assimilation ability of transgenic plants. These characteristics contributed to the increased uptake of limited nitrogen nutrients by transgenic plants, which also reduced the starvation damage to the chloroplasts. Therefore, the MdATG10-overexpressing apple plants could maintain higher photosynthetic ability and possess better growth under nitrogen starvation stress.

scholarly journals Response of Rice Nitrogen Physiology to High Nighttime Temperature during Vegetative Stage

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Song Chen ◽  
Xiaoguo Zhang ◽  
Xia Zhao ◽  
Danying Wang ◽  
Chunmei Xu ◽  
...  
Keyword(s):  
N Uptake ◽  
Plant Morphology ◽  
Carbohydrate Content ◽  
Shoot Biomass ◽  
Nitrogen Accumulation ◽  
Root Volume ◽  
Nitrogen Levels ◽  
Soluble Leaf Protein ◽  
Nitrogen Concentrations ◽  
Positive Effect

The effects of night temperature on plant morphology and nitrogen accumulation were examined in rice (Oryza sativaL.) during vegetative growth. The results showed that the shoot biomass of the plants was greater at 27°C (high nighttime temperature, HNT) than at 22°C (CK). However, the increase in both shoot and root biomasses was not significant under 10 mg N/L. The shoot nitrogen concentrations were 16.1% and 16.7% higher in HNT than in CK under 160 and 40 mg N/L. These results suggest that plant N uptake was enhanced under HNT; however, the positive effect might be limited by the N status of the plants. In addition, leaf area, plant height, root maximum length, root and shoot nitrogen concentrations, soluble leaf protein content, and soluble leaf carbohydrate content were greater in HNT than in CK under 40 and 160 mg N/L, while fresh root volume, root number, and the content of free amino acid in leaf were not significantly different between HNT and CK regardless of nitrogen levels. Moreover, leaf GS activity under HNT was increased at 160 mg N/L compared with that under CK, which might partly explain the positive effect of HNT on soluble protein and carbohydrate content.

Studies on Maize (Zea mays) at Bunda, Malawi. I. Yield in Relation to Rainfall

1989 ◽  
Vol 25 (3) ◽  
pp. 357-366 ◽  
Author(s):  
D. MacColl
Keyword(s):  
Zea Mays ◽  
Growing Season ◽  
The Other ◽  
Negative Effects ◽  
Total Rainfall ◽  
Fertilizer Nitrogen ◽  
Late Planting ◽  
High Rainfall ◽  
Nitrogen Levels

SUMMARYYields of maize were determined in six years, on two soils, at up to four nitrogen levels following early and late planting. Without fertilizer nitrogen, high rainfall at the beginning of the growing season reduced yield on one soil but not on the other, while high rainfall at late silking and high total rainfall in the growing season reduced yields on both soils. As the level of fertilizer nitrogen increased, the negative effects of rainfall on yield tended to disappear. A three week delay in planting sometimes increased and sometimes decreased yield. The probable reasons for the observed effects of rainfall on yield are discussed.

Analysis of the World's First Polymer Injectivity Test in a Carbonate Reservoir Under Extreme Harsh Conditions in ADNOC's Reservoirs

2021 ◽  
Author(s):  
Juan Manuel Leon ◽  
Shehadeh K. Masalmeh ◽  
Siqing Xu ◽  
Ali M. AlSumaiti ◽  
Ahmed A. BinAmro ◽  
...  
Keyword(s):  
High Temperature ◽  
Laboratory Experiments ◽  
High Salinity ◽  
Laboratory Data ◽  
Injection Pressure ◽  
Carbonate Reservoir ◽  
Experimental Program ◽  
Full Field ◽  
Harsh Conditions

Abstract Assessing polymer injectivity for EOR field applications is highly important and challenging. An excessive injectivity reduction during and after polymer injection may potentially affect the well integrity and recovery efficiency and consequently, injection strategy and the economics of the polymer projects. Moreover, well conditions such as skin, completion configuration, and injection water quality can significantly impact polymer injectivity. Additionally, the presence of fractures or micro-fractures may govern injection pressure. In contrast, historic field applications have shown that polymer injectivity is in general better than expected from simulations or laboratory data. In the laboratory experiments, the polymer injectivity has been evaluated by injection of significant amounts of pore volumes of polymer at relevant well-injection rates. In addition, several experiments were performed to measure the complex in-situ rheology expected to dominate the flow near the wellbore This paper presents the analysis of the the world's first polymer injectivity test (PIT) conducted in a high temperature and high salinity (HTHS) carbonate reservoir in Abu Dhabi as part of a comprehensive de-risking program for a new polymer-based EOR scheme proposed by ADNOC for these challenging carbonate reservoirs (see Masalmeh et. al., 2014). The de-risking program includes an extensive laboratory experimental program and field injectivity test to ensure that the identified polymer can be injected and propagated in the target formation before multi-well pilot and full-field implementation stages. Experimental laboratory data and the field injectivity test results are presented in earlier publications (Masalmeh et. al., 2019; Rachapudi et. al., 2020) and references therein. This PIT is the world's first polymer injectivity test in a carbonate reservoir under such harsh conditions of high salinity, high content of divalent ions and high temperature. In addition, the polymer used during the test has never been field-tested before. Therefore, the results of the PIT interpretation will help to de-risk the suitable polymer for the future inter-well pilot for the new proposed EOR Polymer-based scheme and it is a game-changer to unlock several opportunities for different Chemical EOR applications on full-field scale in other reservoirs with similar characteristics. A single well radial simulation model was built to integrate the surveillance data during PIT and the extensive laboratory experiments. Morever, multiple Pressure Fall Off Tests (PFOs) during the same periods were analyzed and intergaretd in the model.The study assessed the effect of polymer viscosity on mobility reduction, evaluated the polymer bank propagation, investigated the effect of the skin build-up, residual resistance factor (RRF) and shear effects on the well injectivity. Additionally, a comprehensive assisted history match method and robust simulation sensitivity analysis was implemented, thousands of sensitivity simulation runs were performed to capture several possible injection scenarios and validate laboratory parameters. The simulation study confirmed that the PIT could be interpreted using the laboratory-measured polymer parameters such as polymer bulk viscosity, in-situ rheology, RRF and adsorption.

GENERATIVE CYCLES OF PROTEIN AND TRANSAMINASE IN THE GROWING CORN RADICLE

1959 ◽  
Vol 37 (4) ◽  
pp. 621-639 ◽  
Author(s):  
F. S. Cook
Keyword(s):  
Enzyme Activity ◽  
Cell Growth ◽  
Growth And Development ◽  
Specific Protein ◽  
Soluble Nitrogen ◽  
Transaminase Activity ◽  
Cell Numbers ◽  
Nitrogen Levels ◽  
Linear Distance ◽  
Cellular Development

Measurements have been made of growth rates, cell numbers, fresh and dry weights, protein and soluble nitrogen levels, and glutamic–aspartic transaminase activity in six successive 2 mm segments of the radicles of 3-day-old corn seedlings. The measured quantities of protein and enzyme activity are related to the stage of average cellular development, to a linear distance scale along the axis of the radicle, and to the time scale. Increments per cell per hour during cell growth are therefore computed. An attempt is made to explain the significance of the genesis of the transaminase in the growth and development of the radicle cells, to the concurrent genesis of total and specific protein, and to other generative cycles.

Response of irrigated soybeans (Glycine max) to phosphorus on an alkaline cracking clay in semi-arid tropical Australia

1986 ◽  
Vol 26 (1) ◽  
pp. 115 ◽  
Author(s):  
AL Garside ◽  
MC Fulton
Keyword(s):  
Glycine Max ◽  
Grain Yield ◽  
Relative Yield ◽  
Grain Protein Content ◽  
Residual Effects ◽  
Seasonal Effects ◽  
Soil P ◽  
P Fertilizer ◽  
Nitrogen Concentrations ◽  
P Application

The primary and residual effects of phosphorus (P) fertilizer on soybeans (Glycine max cv. Buchanan) were studied at one site for three seasons on Cununurra clay in the Ord Irrigation Area. Grain yield increased (P< 0.01) with both primary and residual P in all seasons. When grain yields over the 3 years were standardized to eliminate seasonal effects, relative grain yield (RGY) was positively related to each of bicarbonate-extractable soil P (EP), applied fertilizer P (FP) and fertilizer P applied to the previous crop (PFP). Seventy-three per cent of the variation in relative yield within years could be explained by the equation: RGY = 45.44 + 0.64FP + l.84EP + 0.197PFP R 2 = 0 . 7 3 , P < 0.01 Increasing P status was associated with increased plant height, dry matter production and weight of 100 seeds and increased the number of main-stem nodes, nodules, pods per plant and days to maturity, but had no effect on number of seeds per pod and number of days until commencement and completion of flowering. Concentrations of P in the whole tops and uppermost leaf increased with increasing rate of P application. However, there was a significant P x growth stage interaction on nitrogen concentrations in whole tops and upper-most leaf, these being lower in the high-P plots early in the season. Grain protein content increased with increasing P status while oil content was reduced. The results show that rates of P application higher than those being currently used are required to maximize soybean yield on Cununurra clay.

Effect of Spatial Variation of a Wave Field on the Resulting Ripple Characteristics and Comparison to Present Ripple Predictors

2009 ◽  
Author(s):  
Blake J. Landry ◽  
Yovanni A. Catan˜o-Lopera ◽  
Matthew J. Hancock ◽  
Chiang C. Mei ◽  
Marcelo H. Garci´a
Keyword(s):  
Spatial Variation ◽  
Wave Field ◽  
Test Section ◽  
Laboratory Experiments ◽  
Laboratory Data ◽  
Standing Waves ◽  
Sand Ripple ◽  
Wave Measurements ◽  
Progressive Waves ◽  
Sediment Test

Laboratory experiments analyzed herein focus on the validity of ripple predictors under spatially variable wave envelopes. Present-day ripple predictors commonly derived from laboratory data (for smaller wave periods of about 1 to 4 s) within which only small regions of the facilities were used to observe and measure the sand ripple geometric characteristics of the nearly progressive waves measured overhead. When extended to large sediment test sections, our results show that the predictors are still valid along the tank under wave conditions which have significant wave envelope spatial variation (e.g., standing waves), provided that ripple predictors use the wave measurements directly above the respective locations within the computations. Results indicate that even under the case of mild reflection, noticeable variation in ripple characteristics can be seen along the sediment test section; thus, compels the necessity of measuring the wave field along the entire sediment section to achieve accurate results.

scholarly journals Seismic surveying and imaging at the laboratory scale: A framework to cross-validate experiments and simulations for a salt-body environment

Geophysics ◽  
2020 ◽  
Vol 85 (3) ◽  
pp. T123-T139
Author(s):  
Bence Solymosi ◽  
Nathalie Favretto-Cristini ◽  
Vadim Monteiller ◽  
Paul Cristini ◽  
Bjørn Ursin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Imaging Techniques ◽  
Laboratory Data ◽  
Seismic Exploration ◽  
Scale Model ◽  
Water Tank ◽  
Time Migration ◽  
Reduced Scale

Laboratory experiments have been recently reintroduced into the ideas-to-applications pipeline for geophysical applications. Benefiting from recent technological advances, we believe that in the coming years, laboratory experiments can play a major role in supporting field experiments and numerical modeling, to explore some of the current challenges of seismic imaging in terms of, for instance, acquisition design or benchmarking of new imaging techniques at a low cost and in an agile way. But having confidence in the quality and accuracy of the experimental data obtained in a complex configuration, which mimics at a reduced scale a real geologic environment, is an essential prerequisite. This requires a robust framework regardless of the configuration studied. Our goal is to provide a global overview of this framework in the context of offshore seismics. To illustrate it, a reduced-scale model is used to represent a 3D complex-shaped salt body buried in sedimentary layers with curved surfaces. Zero-offset and offset reflection data are collected in a water tank, using a conventional pulse-echo technique. Then, a cross-validation approach is applied, which allows us, through comparison between experimental data and the numerical simulation, to point out some necessary future improvements of the laboratory setup to increase the accuracy of the experimental data, and the limitations of the numerical implementation that must also be tackled. Due to this approach, a hierarchical list of points can be collected, to which particular attention should be paid to make laboratory experiments an efficient tool in seismic exploration. Finally, the quality of the complex reduced-scale model and the global framework is successfully validated by applying reverse time migration to the laboratory data.

Control of Activated Sludge Filamentous Bulking – IV. Effect of Sludge Regeneration

1982 ◽  
Vol 14 (1-2) ◽  
pp. 73-93 ◽  
Author(s):  
J Chudoba ◽  
M Dohányos ◽  
P Grau
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Concentration Gradient ◽  
Substrate Concentration ◽  
Laboratory Experiments ◽  
Growth Theory ◽  
Significant Relation ◽  
Filamentous Bulking ◽  
Accumulation Capacity ◽  
Feeding Cycle

In addition to the previously published growth theory based on the relation of μ^ to ks , the paper deals with an accumulation-regeneration theory of microorganisms selection. The accumulation-regeneration phenomenon can play a role in population dynamics only in the systems where the accumulated substrate can be subsequently oxidized and thus the accumulation capacity restored in one feeding cycle. This condition can be realized in properly designed systems with the substrate concentration gradient along the reactor. As a criterion of accumulation capacity restoration it is suggested to use the oxidized proportion of the substrate removed in one feeding cycle. Extensive laboratory experiments have shown a significant relation between the SVI and the percentage of the substrate oxidized. Practical consequences of these findings for the control of filamentous activated sludge bulking are also discussed in the present paper.

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