Compensating effect of fulvic acid and super-absorbent polymer on leaf gas exchange and water use efficiency of maize under moderate water deficit conditions

2017 ◽  
Vol 83 (3) ◽  
pp. 351-360 ◽  
Author(s):  
Wei Yang ◽  
Pinfang Li ◽  
Shiwen Guo ◽  
Bingqian Fan ◽  
Riquan Song ◽  
...  
2016 ◽  
Vol 44 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Bianca do Carmo SILVA ◽  
Pêola Reis de SOUZA ◽  
Daihany Moraes CALLEGARI ◽  
Vanessa Ferreira ALVES ◽  
Allan Klynger da Silva LOBATO ◽  
...  

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 µmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Li ◽  
Dagang Guo ◽  
Xiaodong Gao ◽  
Xining Zhao

Elevated atmospheric CO2 concentrations ([eCO2]) and soil water deficits significantly influence gas exchange in plant leaves, affecting the carbon-water cycle in terrestrial ecosystems. However, it remains unclear how the soil water deficit modulates the plant CO2 fertilization effect, especially for gas exchange and leaf-level water use efficiency (WUE). Here, we synthesized a comprehensive dataset including 554 observations from 54 individual studies and quantified the responses for leaf gas exchange induced by e[CO2] under water deficit. Moreover, we investigated the contribution of plant net photosynthesis rate (Pn) and transpiration rates (Tr) toward WUE in water deficit conditions and e[CO2] using graphical vector analysis (GVA). In summary, e[CO2] significantly increased Pn and WUE by 11.9 and 29.3% under well-watered conditions, respectively, whereas the interaction of water deficit and e[CO2] slightly decreased Pn by 8.3%. Plants grown under light in an open environment were stimulated to a greater degree compared with plants grown under a lamp in a closed environment. Meanwhile, water deficit reduced Pn by 40.5 and 37.8%, while increasing WUE by 24.5 and 21.5% under ambient CO2 concentration (a[CO2]) and e[CO2], respectively. The e[CO2]-induced stimulation of WUE was attributed to the common effect of Pn and Tr, whereas a water deficit induced increase in WUE was linked to the decrease in Tr. These results suggested that water deficit lowered the stimulation of e[CO2] induced in plants. Therefore, fumigation conditions that closely mimic field conditions and multi-factorial experiments such as water availability are needed to predict the response of plants to future climate change.


1995 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
J Vadell ◽  
C Cabot ◽  
H Medrano

The effects of drought acclimation on the diurnal time courses of photosynthesis and related characters were studied in Trifolium subterraneum L. leaves during two consecutive late spring days. Leaf CO2 assimilation rate and transpiration rate followed irradiance variations in irrigated plants. Under drought, a bimodal pattern of leaf CO2 assimilation rate developed although stomatal conductance remained uniform and low. Instantaneous water-use efficiency was much higher in droughted plants during the early morning and late evening, while during the middle of the day it was close to the value of irrigated plants. Net carbon gain in plants under drought reached 40% of the carbon gain in irrigated plants with a significant saving of water (80%). Average data derived from midday values of leaf CO2 assimilation rates and instantaneous water-use efficiency did not provide good estimates of the daily carbon gain and water-use efficiency for droughted leaves. Coupled with the morphological changes as a result of acclimation to progressive drought, modifications of diurnal patterns of leaf gas exchange rates effectively contribute to a sustained carbon gain during drought. These modifications significantly improve water-use efficiency, mainly by enabling the plant to take advantage of morning and evening hours with high air humidity.


2012 ◽  
Vol 169 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Antonio Diaz-Espejo ◽  
María Victoria Cuevas ◽  
Miquel Ribas-Carbo ◽  
Jaume Flexas ◽  
Sebastian Martorell ◽  
...  

2018 ◽  
Vol 61 (2) ◽  
pp. 523-531 ◽  
Author(s):  
Rahul Suresh ◽  
Shiv O. Prasher ◽  
Ramanbhai M. Patel ◽  
Zhiming Qi ◽  
Eman Elsayed ◽  
...  

Abstract. There is a need to develop innovative techniques to effectively use water in agriculture to meet the growing demands for food. Super absorbent polymers (SAPs), or hydrogels, can absorb and retain large amounts of water against gravitational forces and release it on demand to meet plant water requirements. Being an artificially synthesized compound, it is imperative that SAPs should not introduce toxicity to the growing medium or produce. The objectives of this study were to determine whether SAPs can improve water use efficiency (WUE) and the physiological growth of cherry tomatoes ( var. ) without causing soil toxicity. A pot-trial experiment was carried out in 2014 at the Research Greenhouse of McGill University’s Macdonald Campus (Ste-Anne-de-Bellevue, Quebec, Canada) in a completely randomized design, with three concentrations of SAP (0%, 0.1%, and 0.5%) and three irrigation intervals (daily, each alternate day, and every third day). The mean yield of the experimental cherry tomatoes was statistically significantly higher where 0.5% SAP was applied, compared to where SAP was not applied (p = 0.0056). The mean WUE was also higher where 0.5% SAP was applied when compared to where SAP was not applied (p = 0.05). To ascertain food safety, the presence of free acrylamide monomer in tomatoes was checked. The acrylamide concentrations were below the detection limit of 5 µg kg-1 in all tomato samples. To assess environmental toxicity, a Microtox toxicology analysis was also conducted on the growing medium, which revealed that the SAP used in the study was not toxic. Therefore, it can be concluded that the application of SAP could increase yield and WUE of greenhouse-grown cherry tomatoes. It also appears that SAP did not introduce toxic side-effects in the soil nor in the tomatoes, as determined by Microtox acute toxicity test and acrylamide residue analysis with LC-MS. Keywords: Acrylamide, Cherry tomatoes, Greenhouse, Microtox, Monomer, Super absorbent polymer, Toxicity, Water use efficiency, Yield.


2015 ◽  
Vol 7 (3) ◽  
pp. 338-344 ◽  
Author(s):  
Hamid-Reza FALLAHI ◽  
Reza TAHERPOUR KALANTARI ◽  
Mahsa AGHHAVANI-SHAJARI ◽  
Mohammad-Ghasem SOLTANZADEH

Sustainable use of water resources in agriculture is a necessity for many arid countries. In order to investigate the effect of water deficit, irrigation after 120 (control), 155 (moderate water stress) and 190 mm (sever water stress) pan evaporation and super absorbent polymer rates (SAP) (0, 30, 60 and 90 kg ha-1) on growth, yield and water use efficiency of cotton, an experiment was conducted as split plot based on a randomized complete block design with three replications. Moreover, the effect of water quality (distilled water and solutions of 0.25, 0.5, 0.75, 1 and 1.25% NaCl) was investigated on water holding capacity by SAP. Results revealed that moderate water stress (irrigation intervals of aprox. 15 days) along with 60 kg ha-1 SAP application was the best treatment in terms of growth and yield indices of cotton. The results for plant height, plant dry weight, boll number per plant and fiber yield in this treatment were 16, 28, 42 and 10% higher than control treatment, respectively. Water deficit and SAP application improved the water use efficiency (WUE) of cotton. The amount of WUE in moderate water stress treatment along with consumption of 60 or 90 kg ha-1 SAP was 26% higher than for control treatment. In addition, water holding capacity by SAP in distilled water treatment was 7 times higher than in the case of 1.25% NaCl solution. The overall results showed that irrigation deficit and SAP application are two appropriate strategies for crop production in areas affected by drought stress, especially if low saline water sources are used.


2012 ◽  
Vol 5 (3) ◽  
pp. 653-668 ◽  
Author(s):  
Christine E. Edwards ◽  
Brent E. Ewers ◽  
C. Robertson McClung ◽  
Ping Lou ◽  
Cynthia Weinig

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