scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.


1999 ◽  
Vol 26 (8) ◽  
pp. 737 ◽  
Author(s):  
Marcus Schortemeyer ◽  
Owen K. Atkin ◽  
Nola McFarlane ◽  
John R. Evans

The interactive effects of nitrate supply and atmospheric CO2 concentration on growth, N2 fixation, dry matter and nitrogen partitioning in the leguminous tree Acacia melanoxylon R.Br. were studied. Seedlings were grown hydroponically in controlled-environment cabinets for 5 weeks at seven 15N-labelled nitrate levels, ranging from 3 to 6400 mmol m–3. Plants were exposed to ambient (~350 µmol mol–1) or elevated (~700 µmol mol–1) atmospheric CO2 for 6 weeks. Total plant dry mass increased strongly with nitrate supply. The proportion of nitrogen derived from air decreased with increasing nitrate supply. Plants grown under either ambient or elevated CO2 fixed the same amount of nitrogen per unit nodule dry mass (16.6 mmol N per g nodule dry mass) regardless of the nitrogen treatment. CO2 concentration had no effect on the relative contribution of N2 fixation to the nitrogen yield of plants. Plants grown with ≥50 mmol m–3 N and elevated CO2 had approximately twice the dry mass of those grown with ambient CO2 after 42 days. The rates of net CO2 assimilation under growth conditions were higher per unit leaf area for plants grown under elevated CO2. Elevated CO2 also decreased specific foliage area, due to an increase in foliage thickness and density. Dry matter partitioning between plant organs was affected by ontogeny and nitrogen status of the plants, but not by CO2 concentration. In contrast, plants grown under elevated CO2 partitioned more of their nitrogen to roots. This could be attributed to reduced nitrogen concentrations in foliage grown under elevated CO2.


2014 ◽  
Vol 41 (11) ◽  
pp. 1138 ◽  
Author(s):  
Gorka Erice ◽  
Alvaro Sanz-Sáez ◽  
Amadeo Urdiain ◽  
Jose L. Araus ◽  
Juan José Irigoyen ◽  
...  

Despite its relevance, few studies to date have analysed the role of harvest index (HI) in the responsiveness of wheat (Triticum spp.) to elevated CO2 concentration ([CO2]) under limited water availability. The goal of the present work was to characterise the role of HI in the physiological responsiveness of durum wheat (Triticum durum Desf.) exposed to elevated [CO2] and terminal (i.e. during grain filling) water stress. For this purpose, the performance of wheat plants with high versus low HI (cvv. Sula and Blanqueta, respectively) was assessed under elevated [CO2] (700 μmol mol–1 vs 400 μmol mol–1 CO2) and terminal water stress (imposed after ear emergence) in CO2 greenhouses. Leaf carbohydrate build-up combined with limitations in CO2 diffusion (in droughted plants) limited the responsiveness to elevated [CO2] in both cultivars. Elevated [CO2] only increased wheat yield in fully watered Sula plants, where its larger HI prevented an elevated accumulation of total nonstructural carbohydrates. It is likely that the putative shortened grain filling period in plants exposed to water stress also limited the responsiveness of plants to elevated [CO2]. In summary, our study showed that even under optimal water availability conditions, only plants with a high HI responded to elevated [CO2] with increased plant growth, and that terminal drought constrained the responsiveness of wheat plants to elevated [CO2].


2017 ◽  
Vol 3 (02) ◽  
pp. 73-77
Author(s):  
Supriya Tiwari ◽  
N. K. Dubey

Increasing Carbon dioxide (CO2) is an important component of global climate change that has drawn the attention of environmentalists worldwide in the last few decades. Besides acting as an important greenhouse gas, it also produces a stimulatory effect, its instantaneous impact being a significant increase in the plant productivity. Atmospheric CO2 levels have linearly increased from approximately 280 parts per million (ppm) during pre-industrial times to the current level of more than 390 ppm. In past few years, anthropogenic activities led to a rapid increase in global CO2 concentration. Current Intergovernmental Panel on Climate Change (IPCC) projection indicates that atmospheric CO2 concentration will increase over this century, reaching 730-1020 ppm by 2100. An increase in global temperature, ranging from 1.1 to 6.4oC depending on global emission scenarios, will accompany the rise in atmospheric CO2. As CO2 acts as a limiting factor in photosynthesis, the immediate effect of increasing atmospheric CO2 is improved plant productivity, a feature commonly termed as “CO2 fertilization”. Variability in crop responses to the elevated CO2 made the agricultural productivity and food security vulnerable to the climate change. Several studies have shown significant CO2 fertilization effect on crop growth and yield. An increase of 30 % in plant growth and yield has been reported when CO2 concentration has been doubled from 330 to 660 ppm. However, the fertilization effect of elevated CO2 is not very much effective in case of C4 plants which already contain a CO2 concentration mechanism, owing to their specific leaf 2 anatomy called kranz anatomy. As a result, yield increments observed in C4plants are comparatively lower than the C3 plants under similar elevated CO2 concentrations. This review discusses the trends and the causes of increasing CO2 concentration in the atmosphere, its effects on the crop productivity and the discrepancies in the response of C3 and C4 plants to increasing CO2 concentrations.


2016 ◽  
Vol 43 (12) ◽  
pp. 1183 ◽  
Author(s):  
João Paulo Souza ◽  
Nayara M. J. Melo ◽  
Eduardo G. Pereira ◽  
Alessandro D. Halfeld ◽  
Ingrid N. Gomes ◽  
...  

The rise in atmospheric CO2 concentration ([CO2]) has been accompanied by changes in other environmental factors of global climate change, such as drought. Tracking the early growth of plants under changing conditions can determine their ecophysiological adjustments and the consequences for ecosystem functions. This study investigated long-term ecophysiological responses in three woody Cerrado species: Hymenaea stigonocarpa Mart. ex Hayne, Solanum lycocarpum A. St.-Hil. and Tabebuia aurea (Silva Manso) Benth. and Hook. f. ex S. Moore, grown under ambient and elevated [CO2]. Plants were grown for 515 days at ambient (430 mg dm–3) or elevated [CO2] (700 mg dm–3). Some plants were also subjected to water stress to investigate the synergy between atmospheric [CO2] and soil water availability, and its effect on plant growth. All three species showed an increase in maximum net photosynthesis (PN) and chlorophyll index under high [CO2]. Transpiration decreased in some species under high [CO2] despite daily watering and a corresponding increase in water use efficiency was observed. Plants grown under elevated [CO2] and watered daily had greater leaf area and total biomass production than plants under water stress and ambient [CO2]. The high chlorophyll and PN in cerrado plants grown under elevated [CO2] are an investment in light use and capture and higher Rubisco carboxylation rate, respectively. The elevated [CO2] had a positive influence on biomass accumulation in the cerrado species we studied, as predicted for plants under high [CO2]. So, even with water stress, Cerrado species under elevated [CO2] had better growth.


Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 484
Author(s):  
Zou ◽  
Liu ◽  
Chen ◽  
Fernando

Global warming by increased atmospheric CO2 concentration has been widely accepted. Yet, there has not been any consistent conclusion on the doubled CO2 concentration that in the future will affect plant disease incidence and severity. Blackleg disease, mainly caused by Leptosphaeria maculans, is a major disease on canola production globally. Brassica napus and L. maculans have a gene-for-gene interaction, which causes an incompatible reaction between canola plants carrying resistance genes and L. maculans isolates carrying corresponding avirulence genes. In this study, B. napus varieties and lines inoculated with different Leptosphaeria isolates were subjected to simulated growth conditions, namely, growth chambers with normal environments and with controlled CO2 concentrations of 400, 600, and 800 ppm. The results indicated that the elevated CO2 concentrations have no noticeable effect on the inferred phenotypes of the canola–blackleg interactions. However, the disease severity decreased in most of the B. napus–L. maculans interactions at extremely high CO2 concentration (800 ppm). The varied pathogenicity changes of the B. napus–L. maculans pathosystem under elevated CO2 concentrations at 400 or 600 ppm may be due to the genetic background or physiological differences in plants and pathogenicity differences in L. maculans isolates having different Avr gene profiles. The mechanisms by which elevated CO2 concentrations affect the B. napus–L. maculans pathosystem will help us understand how climate change will impact crops and diseases.


2021 ◽  
Vol 42 (4) ◽  
pp. 2151-2162
Author(s):  
Jéssica de Oliveira Santos ◽  
◽  
Francislene Angelotti ◽  
Tiago Cardoso da Costa-Lima ◽  
◽  
...  

An increase in the carbon dioxide concentration (CO2) in the atmosphere has occurred in recent years, influencing the different biological aspects of herbivorous insects. The present study aimed to evaluate the effect of CO2 increase on the biological aspects of Liriomyza sativae Blanchard leafminer in melon plants. For this, two experiments were carried out: (i) to evaluate the effect of melon plants grown in CO2-enriched environments on the immature developmental stages of L. sativae and L. sativae adult longevity, and (ii) to verify the impact of increased CO2 concentration on L. sativae adult survival, feeding punctures, and oviposition. The experiments were carried out in growth chambers maintained in the temperature regime of 20-26-33 °C (simulating the minimum, average, and maximum daily temperature) and under two CO2 concentrations (400 ppm and 770 ppm). The immature stages and the egg-adult period of L. sativae were longer when they developed on plants grown in high CO2 levels (770 ppm), but no difference in adult longevity was observed. The viability of the immature phases was not different between the two CO2 concentrations. Furthermore, there was no difference in the number of eggs and feeding punctures between treatments. Thus, the increase in CO2 concentration prolongs the duration of the immature stages of L. sativae; however, it does not affect their viability. Adult survival, fertility, and feeding punctures were also unmodified by the environment enriched with CO2.


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