Carbon Balance, Transpiration, and Biomass Partitioning of Glyphosate-Treated Wheat (Triticum aestivum) Plants

Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 333-339 ◽  
Author(s):  
Carlos J. Fernandez ◽  
Kevin J. McInnes ◽  
J. Tom Cothren
Keyword(s):  
Environmental Conditions ◽  
Carbon Balance ◽  
Test Chamber ◽  
Biomass Partitioning ◽  
Dew Point ◽  
Carbon Uptake ◽  
Carbon Loss ◽  
Whole Plant ◽  
Loam Soil ◽  
Companion Plants

Whole plant studies were conducted to examine the effects of glyphosate on components of carbon balance, transpiration, and biomass partitioning of wheat plants grown in Olton sandy clay loam soil and in a well-aerated fritted clay medium under controlled environmental conditions. Well-irrigated plants were transferred from a nursery room into a test chamber about 48 d after planting. Two to five days later, 12 to 42 ml of a glyphosate solution with a concentration of 480 mg ai L–1were sprayed until full coverage of the foliage. Environmental conditions in the chamber were air temperature 25 C, dew point 18 C, windspeed 1.1 m s–1, and PPFD 1500 mmol m–2s–1(at the top of the foliage) for 12 h daily. Glyphosate treatment resulted in destruction of the root system, as determined at the end of the tests, and at the start of tests using companion plants. Plants grown in soil lost 0.53 kg kg–1of the initial root mass, while this loss was 0.38 kg kg–1in plants grown in fritted clay. Glyphosate treatment rapidly inhibited daily rates of gross carbon uptake and transpiration of wheat plants grown in both media. Effects occurred more than twice as rapidly in plants grown in soil as in fritted day. Similarity in the patterns of inhibition of gross carbon uptake and transpiration suggests that glyphosate may also affect leaf stomata. After applying glyphosate, daily rates of carbon loss increased for 3 d in soil-grown plants but remained almost constant for 10 d in plants grown in fritted clay; thereafter, the rates of carbon loss declined. The early increase or the constancy of carbon loss observed after applying glyphosate was related to catabolic processes occurring in roots.

Grapevines under drought do not express esca leaf symptoms

2021 ◽  
Vol 118 (43) ◽  
pp. e2112825118
Author(s):  
Giovanni Bortolami ◽  
Gregory A. Gambetta ◽  
Cédric Cassan ◽  
Silvina Dayer ◽  
Elena Farolfi ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Stress Responses ◽  
Carbon Balance ◽  
Nonstructural Carbohydrates ◽  
Complex Interactions ◽  
Whole Plant ◽  
Underlying Causes ◽  
Abiotic And Biotic Factors ◽  
Leaf Symptoms

In the context of climate change, plant mortality is increasing worldwide in both natural and agroecosystems. However, our understanding of the underlying causes is limited by the complex interactions between abiotic and biotic factors and the technical challenges that limit investigations of these interactions. Here, we studied the interaction between two main drivers of mortality, drought and vascular disease (esca), in one of the world’s most economically valuable fruit crops, grapevine. We found that drought totally inhibited esca leaf symptom expression. We disentangled the plant physiological response to the two stresses by quantifying whole-plant water relations (i.e., water potential and stomatal conductance) and carbon balance (i.e., CO2 assimilation, chlorophyll, and nonstructural carbohydrates). Our results highlight the distinct physiology behind these two stress responses, indicating that esca (and subsequent stomatal conductance decline) does not result from decreases in water potential and generates different gas exchange and nonstructural carbohydrate seasonal dynamics compared to drought.

EFFECT OF AIR VELOCITY ON INHALATION DOSES DUE TO RADON AND THORON PROGENY IN A TEST CHAMBER

2020 ◽  
Vol 189 (3) ◽  
pp. 401-405
Author(s):  
Rosaline Mishra ◽  
Rama Prajith ◽  
Rajeswari Pradhan Rout ◽  
Jalaluddin Sriamirullah ◽  
Balwinder Kaur Sapra
Keyword(s):  
Physical Properties ◽  
Environmental Conditions ◽  
Test Chamber ◽  
Air Velocity ◽  
Attachment Rate ◽  
Inhalation Dose ◽  
Decay Products ◽  
Calibration Chamber ◽  
Thoron Progeny

Abstract Inhalation doses due to radon and thoron are predominantly due to the inhalation of progeny of Radon and Thoron. The progeny/decay-products of radon and thoron are particulates unlike their parent gas and exhibit different physical properties like attachment to the aerosols and deposition on different surfaces. All these properties in turn depend on the environmental conditions such as air velocity, aerosol concentration, attachment rate, etc. The role of air velocity on deposition on surfaces decides the progeny particles left in the air for inhalation. Therefore, in the present work, we have studied the effect of air velocity on the inhalation dose due to radon and thoron progeny at the centre of a 0.5-m3 calibration chamber as well as on all surfaces. Hence, the studies were carried out at different air velocities, and inhalation doses were measured using deposition-based direct radon and thoron progeny sensors.

Lascar EL-WiFi-TH Data Logger

2020 ◽  
Vol 22 (1) ◽  
pp. 41-45
Author(s):  
Heather Parks
Keyword(s):  
Environmental Conditions ◽  
Cloud Service ◽  
Dew Point ◽  
Data Logger ◽  
Strong Unit ◽  
Data Loggers ◽  
Intended Use

The Lascar Data Logger system includes three parts: the data loggers, EasyLog WiFi Software, and the EasyLog Cloud service. The intended use is to monitor and record the temperature, humidity, and dew point of the space surrounding the data logger to aid in achieving optimal environmental conditions of the collection. While it is a strong unit, there are competitors that might be a better fit for an institution.

Decontamination of Bacillus Spores with Formaldehyde Vapor Under Varied Environmental Conditions

2020 ◽  
pp. 153567602092697
Author(s):  
Young W. Choi ◽  
Michelle M. Sunderman ◽  
Martha W. McCauley ◽  
William R. Richter ◽  
Zachary J. Willenberg ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Time Course ◽  
Test Chamber ◽  
Air Concentration ◽  
Air Samples ◽  
Circulating Water ◽  
Surface Areas ◽  
Formaldehyde Vapor ◽  
Chamber Temperature ◽  
Bacillus Spores

Introduction: This effort investigated formaldehyde vapor characteristics under various environmental conditions by the analyses of air samples collected over a time-course. This knowledge will help responders achieve desired formaldehyde exposure parameters for decontamination of affected spaces after a biological contamination incident. Methods: Prescribed masses of paraformaldehyde and formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor. Adsorbent cartridges were used to collect air samples from the test chamber at predetermined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. In addition, material demand for the formaldehyde was evaluated by inclusion of arrays of Plexiglas panels in the test chamber to determine the effect of varied surface areas within the test chamber. Temperature was controlled with a circulating water bath connected to a radiator and fan inside the chamber. Relative humidity was controlled with humidity fixed-point salt solutions and water vapor generated from evaporated water. Results: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations in the ambient temperature trials (approximately 22°C). The addition of clear Plexiglas panels to increase the surface area of the test chamber interior resulted in appreciable decreases of formaldehyde air concentration when compared to an empty test chamber. Conclusion: This work has shown that environmental variables and surface-to-volume ratios in the decontaminated space may affect the availability of formaldehyde in the air and, therefore, may affect decontamination effectiveness.

scholarly journals Thrips and Bollworm Control in Bt Cotton 1996

1997 ◽  
Vol 22 (1) ◽  
pp. 274-275
Author(s):  
T. G. Teague ◽  
N. P. Tugwell
Keyword(s):  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Bt Cotton ◽  
Whole Plant ◽  
Pest Insects ◽  
Loam Soil ◽  
Detergent Mixture

Abstract Cotton was planted 25 May 1996 on the Judd Hill Plantation near Truman, AR in Mhoon sandy loam soil. Plots were 8 rows (38 inch centers) wide and 40 ft long separated by 2 unplanted rows and 10 ft alleys. Irrigation was supplied by flooding furrows. Treatments were arranged in a RCBD with 4 replications. Temik was applied at planting using Gandy boxes. The sidedress application was made on 3 Jul. Baythroid was applied using a 4-row CO2 charged backpack sprayer calibrated to deliver 13 gpa at 20 psi with 1 TJ-50 8002vs nozzle per row. Thrips were monitored by using whole plant washes of a detergent mixture with an alcohol rinse. Plants were monitored for pest insects and damage through the season and were mapped at harvest.

How Plants Enhance Weathering and How Weathering is Important to Plants

Elements ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 241-246 ◽  
Author(s):  
Stephen Porder
Keyword(s):  
Terrestrial Ecosystems ◽  
Carbon Uptake ◽  
Rock Weathering ◽  
Earth System ◽  
Agricultural Systems ◽  
Carbon Loss ◽  
Weathering Rates ◽  
Environmental Consequences ◽  
The Earth ◽  
Primary Minerals

Since land plants emerged from swampy coastlines over 400 million years ago, they have played a fundamental role in shaping the Earth system. Roots and associated fungi increase rock weathering rates, providing access to nutrients, while altering atmospheric CO2. As soils weather, the dissolution of primary minerals forces plants to rely on recycling and atmospheric deposition of rock-derived nutrients. Thus, for many terrestrial ecosystems, weathering ultimately constrains primary production (carbon uptake) and decomposition (carbon loss). These constraints are most acute in agricultural systems, which rely on mined fertilizer rather than the recycling of organic material to maintain production. Humans now mine similar amounts of some elements as weather out of rocks globally. This increase in supply has myriad environmental consequences.

Degradation and Leaching of Methazole in Soil

Weed Science ◽  
1977 ◽  
Vol 25 (4) ◽  
pp. 304-308 ◽  
Author(s):  
F.E. Brockman ◽  
W.B. Duke
Keyword(s):  
Environmental Conditions ◽  
Sandy Loam ◽  
Total Radioactivity ◽  
Growth Chamber ◽  
Simulated Rainfall ◽  
Soil Columns ◽  
Rainfall Simulator ◽  
Loam Soil ◽  
Original Amount ◽  
Over Time

The degradation and leaching of methazole [2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione] and metabolites in Elmwood sandy loam soil over time in response to average spring environmental conditions was studied by using soil columns placed on a rainfall simulator in an environmental growth chamber. Methazole was degraded to 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU) and 3-(3,4-dichlorophenyl) urea (DCPU) over a 6-week period following methazole application, during which the soil columns received simulated rainfall of 1.27 cm every fourth day. Methazole level decreased to 27% of the original amount while DCPMU and DCPU levels increased to 53% and 1%, respectively. Of the total radioactivity remaining in the soil columns after 44 days and after 14 cm rainfall, approximately 80% remained above a depth of 6.35 mm.

THE PELTIER EFFECT AND ITS USE FOR DETERMINING RELATIVE ACTIVITY OF SOIL WATER

1959 ◽  
Vol 39 (1) ◽  
pp. 76-85 ◽  
Author(s):  
H. C. Korven ◽  
S. A. Taylor
Keyword(s):  
Relative Activity ◽  
Dew Point ◽  
Peltier Effect ◽  
Silty Clay ◽  
Constant Temperature Bath ◽  
Clay Loam Soil ◽  
Silty Clay Loam ◽  
Laboratory Procedure ◽  
Loam Soil ◽  
Membrane Methods

An apparatus is described which involves the use of a small thermocouple, cooled to the dew point by the Peltier effect, as a means of determining the relative activity of water in soils.Thermocouples were calibrated over a series of sulphuric acid solutions immersed in a constant temperature bath controlled to within 0.003 °C. The temperature of the bath for all readings was 25 °C. Readings were taken over Benjamin silty clay loam soil samples that had been brought to desired soil moisture relative activities by the pressure plate and pressure membrane methods. The following conclusions were reached:1. The thermocouple technique shows promise as a laboratory procedure for determining the relative activity of water in soils.2. The majority of the results showed a gradual lowering of the readings with time. This was overcome at the expense of speed by treating the thermocouple with a plastic spray paint.3. More study and testing are required before the technique can be considered a completely satisfactory procedure.

Natural carbon release over-rides anthropogenic carbon uptake when Southern Hemispheric westerlies strengthen

2020 ◽  
Author(s):  
Paul Spence ◽  
Laurie Menviel ◽  
Darryn Waugh
Keyword(s):  
Total Carbon ◽  
Carbon Uptake ◽  
Cycle Model ◽  
Carbon Loss ◽  
Carbon Cycle Model ◽  
Anthropogenic Carbon ◽  
Carbon Release ◽  
Natural Carbon ◽  
Ocean Carbon ◽  
The Impact

<p>The Southern Ocean is one of today's largest sink of carbon, having absorbed about 10\% of the anthropogenic carbon emissions. Southern Ocean's dynamics are principally modulated by the strength of the Southern Hemispheric westerlies,  which are projected to increase over the coming century. Here, using a high-resolution ocean-sea-ice-carbon cycle model, we explore the impact of idealized changes in Southern Hemispheric westerlies on the ocean carbon storage . We find that a 20\% strengthening of the Southern Hemispheric westerlies leads to a $\sim$25 Gt loss of natural carbon, while an additional 13 Gt of anthropogenic carbon is absorbed compared to the control run, thus resulting in a net loss of $\sim$12 GtC from the ocean over a period of 42 years. This tendency is enhanced if the westerlies are also shifted polewards, with a total natural carbon loss of almost 37 GtC, and an additional anthropogenic carbon uptake of 18 GtC. While both experiments display a large natural carbon loss south of 10$^\circ$S, the amplitude is three times greater in the poleward strengthening case, which is  not fully compensated by the increase in anthropogenic carbon content. However, the poleward wind shift leads to significant differences in the pattern of DIC change due to a weakening of the upper overturning cell,  which leads to an increase in natural and total carbon north of 35$^\circ$S in the upper 2000 m.</p>

scholarly journals Sub-grid scale representation of vegetation in global land surface schemes: implications for estimation of the terrestrial carbon sink

2013 ◽  
Vol 10 (10) ◽  
pp. 16003-16041 ◽  
Author(s):  
J. R. Melton ◽  
V. K. Arora
Keyword(s):  
Water Balance ◽  
Environmental Conditions ◽  
Land Surface ◽  
Carbon Balance ◽  
Spatial Representation ◽  
Carbon Sink ◽  
Terrestrial Ecosystem ◽  
Terrestrial Carbon ◽  
Global Land ◽  
Terrestrial Carbon Sink

Abstract. Terrestrial ecosystem models commonly represent vegetation in terms of plant functional types (PFTs) and use their vegetation attributes in calculations of the energy and water balance and to investigate the terrestrial carbon cycle. To accomplish these tasks, two approaches for PFT spatial representation are widely used: "composite" and "mosaic". The impact of these two approaches on the global carbon balance has been investigated with the Canadian Terrestrial Ecosystem Model (CTEM v 1.2) coupled to the Canadian Land Surface Scheme (CLASS v 3.6). In the composite (single-tile) approach, the vegetation attributes of different PFTs present in a grid cell are aggregated and used in calculations to determine the resulting physical environmental conditions (soil moisture, soil temperature, etc.) that are common to all PFTs. In the mosaic (multi-tile) approach, energy and water balance calculations are performed separately for each PFT tile and each tile's physical land surface environmental conditions evolve independently. Pre-industrial equilibrium CLASS-CTEM simulations yield global totals of vegetation biomass, net primary productivity, and soil carbon that compare reasonably well with observation-based estimates and differ by less than 5% between the mosaic and composite configurations. However, on a regional scale the two approaches can differ by > 30%, especially in areas with high heterogeneity in land cover. Simulations over the historical period (1959–2005) show different responses to evolving climate and carbon dioxide concentrations from the two approaches. The cumulative global terrestrial carbon sink estimated over the 1959–2005 period (excluding land use change (LUC) effects) differs by around 5% between the two approaches (96.3 and 101.3 Pg, for the mosaic and composite approaches, respectively) and compares well with the observation-based estimate of 82.2 ± 35 Pg C over the same period. Inclusion of LUC causes the estimates of the terrestrial C sink to differ by 15.2 Pg C (16%) with values of 95.1 and 79.9 Pg C for the mosaic and composite approaches, respectively. Spatial differences in simulated vegetation and soil carbon and the manner in which terrestrial carbon balance evolves in response to LUC, in the two approaches, yields a substantially different estimate of the global land carbon sink. These results demonstrate that the spatial representation of vegetation has an important impact on the model response to changing climate, atmospheric CO2 concentrations, and land cover.

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