scholarly journals Characterization of coffee cultivars leaf rust-resistant subjected to framework pruning

2018 ◽  
Vol 13 (1) ◽  
pp. 63 ◽  
Author(s):  
Estevam Antonio Chagas Reis ◽  
Tainah Freitas ◽  
Milene Alves de Figueiredo Carvalho ◽  
Antônio Nazareno Guimarães Mendes ◽  
Tiago Teruel Rezende ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Leaf Rust ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Agronomic Traits ◽  
High Yield ◽  
Area Index ◽  
Use Efficiency

The goal of our work was to evaluate physiological and agronomic traits, as well as the relationship between these traits in coffee cultivars coming from a germplasm supposedly resistant to leaf rust, and their response to framework pruning. The experiment was conducted at the Federal University of Lavras in randomized blocks with three replicates, with spacing of 3.5 x 0.7 m and plots of 12 plants. An amount of 25 coffee cultivars was evaluated, from which 23 were considered resistant and two susceptible to leaf rust. Traits analyzed were the plagiotropic branch length and number of nodes, net photosynthetic rate, transpiration rate, water use efficiency, fluorescence and chlorophyll index, leaf area index, leaf rust incidence and yield. Catucaí Amarelo 20/15 cv 479, Araponga MG1 and Tupi IAC 1669-33 cultivars show highly responsive to framework pruning. These cultivars have high yield associated to high net photosynthetic rate, water use efficiency and low transpiration rate. Moreover, the last two cultivars show a low incidence of leaf rust. The Acauã cultivar has a good response to framework pruning, showing high yield associated to lower incidence of leaf rust. Catucaí Vermelho 785/15 cultivar is not responsive to framework pruning because show lower yield, high incidence of leaf rust, low vegetative growth and low water use efficiency.

Significant relationships among frost tolerance and net photosynthetic rate, water use efficiency and dehydrin accumulation in cold-treated winter oilseed rapes

2013 ◽  
Vol 170 (18) ◽  
pp. 1600-1608 ◽  
Author(s):  
Milan Oldřich Urban ◽  
Miroslav Klíma ◽  
Pavel Vítámvás ◽  
Jakub Vašek ◽  
Alois Albert Hilgert-Delgado ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Frost Tolerance ◽  
Significant Relationships ◽  
Use Efficiency

Diurnal Variation of Instantaneous CO2 and H2O Gas-Exchange over Canopy and Leaf Level of Spring Maize in Arid Area

2013 ◽  
Vol 807-809 ◽  
pp. 1829-1838 ◽  
Author(s):  
Jia Xuan Guo ◽  
Xu Rong Mei ◽  
Yu Zhong Li
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Arid Area ◽  
Theory And Practice ◽  
Filling Stage ◽  
Leaf Level ◽  
Use Efficiency

Information on the relationship between crop photosynthetic rate and water use efficiency at the leaf level and these at the canopy level is important on the study of theory and practice of high efficiency and water-saving agriculture. We simultaneous made instantaneous CO2 and H2O exchange rate, and instantaneous water use efficiency measurement at both leaf and canopy level in a rain-fed cropping system with spring corn during filling stage by Li-6400 infrared gas analysis meter and eddy correlation system. The results showed that in arid area water stress was the mainly factor influencing the net photosynthesis rate and water use efficiency. At the diurnal course, when soil relative moisture was about 40% at 0-100 cm soil layer, the maximum of net photosynthetic rate at leaf level occurred at about 10:00 under soil water stress, and at about 12:00 at canopy level on sunny days, the maximum leaf photosynthetic rate reached 1.3 mgm-2s-1 , almost close to those of irrigation corn at similar latitude area, and the maximum canopy assimilation rate were 0.9 mgm-2s-1 , reached 54.5% of those of irrigation corn at similar latitude area during filling stage, respectively;The maximum values of instantaneous water use efficiency at leaf and canopy level were 0.16 g (CO2)/ g (H2O) and 0.06 g (CO2)/ g (H2O), and ranged between 0.0055g (CO2)/ g (H2O) and 0.0123 g (CO2)/ g (H2O), 0.0113 g (CO2)/ g (H2O) and 0.0197 g (CO2)/ g (H2O) around noon, respectively. Instantaneous net photosynthetic rate and water use efficiency at leaf level were higher than those at canopy level after 10:00.

scholarly journals Study on the photosynthetic characteristics of Eutrema japonica (Siebold) Koidz. under the pulsed LEDs for simulated sunflecks

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Jae Hoon Park ◽  
Sang Bum Kim ◽  
Eung Pill Lee ◽  
Seung Yeon Lee ◽  
Eui Joo Kim ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Partial Pressure ◽  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Light Stress ◽  
Light Condition ◽  
Duty Ratio ◽  
Use Efficiency

Abstract Background The sunfleck is an important light environmental factor for plants that live under the shade of trees. Currently, the smartfarm has a system that can artificially create these sunfleks. Therefore, it was intended to find optimal light conditions by measuring and analyzing photosynthetic responses of Eutrema japonica (Miq.) Koidz., a plant living in shade with high economic value under artificial sunflecks. Results For this purpose, we used LED pulsed light as the simulated sunflecks and set the light frequency levels of six chambers to 20 Hz, 60 Hz, 180 Hz, 540 Hz, 1620 Hz, and 4860 Hz of a pulsed LED grow system in a plant factory and the duty ratio of the all chambers was set to 30%, 50%, and 70% every 2 weeks. We measured the photosynthetic rate, transpiration rate, stomatal conductance, and substomatal CO2 partial pressure of E. japonica under each light condition. We also calculated the results of measurement, A/Ci, and water use efficiency. According to our results, the photosynthetic rate was not different among different duty ratios, the transpiration rate was higher at the duty ratio of 70% than 30% and 50%, and stomatal conductance was higher at 50% and 70% than at 30%. In addition, the substomatal CO2 partial pressure was higher at the duty ratio of 50% than 30% and 70%, and A/Ci was higher at 30% than 50% and 70%. Water use efficiency was higher at 30% and 50% than at 70%. While the transpiration rate and stomatal conductance generally tended to become higher as the frequency level decreased, other physiological items did not change with different frequency levels. Conclusions Our results showed that 30% and 50% duty ratios could be better in the cultivation of E. japonica due to suffering from water stress as well as light stress in environments with the 70% duty ratio by decreasing water use efficiency. These results suggest that E. japonica is adapted under the light environment with nature sunflecks around 30–50% duty ratio and low light frequency around 20 Hz.

scholarly journals Optimizing Grain Yield and Water Use Efficiency Based on the Relationship between Leaf Area Index and Evapotranspiration

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Leaf Area Index ◽  
Water Use ◽  
Plant Density ◽  
Maize Yield ◽  
Area Index ◽  
Irrigation Level ◽  
Use Efficiency ◽  
The Relationship

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.

Heritabilities of Water‐Use Efficiency Traits and Correlations with Agronomic Traits in Water‐Stressed Alfalfa

Crop Science ◽  
1999 ◽  
Vol 39 (2) ◽  
pp. 494-498 ◽  
Author(s):  
Ian M. Ray ◽  
M. Shaun Townsend ◽  
Cherokee M. Muncy ◽  
John A. Henning
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Agronomic Traits ◽  
Use Efficiency

Potential yield and water-use efficiency benefits in sorghum from limited maximum transpiration rate

2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Simulation Analysis ◽  
Stomatal Closure ◽  
Risk Attitude ◽  
Potential Yield ◽  
Yield Increase ◽  
Use Efficiency ◽  
Yield Responses

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.

Effect of drought stress on residual transpiration and its relationship with water use of wheat

1991 ◽  
Vol 71 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. M. Clarke ◽  
R. A. Richards ◽  
A. G. Condon
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Osmotic Potential ◽  
Water Status ◽  
Yield Potential ◽  
Cuticular Transpiration ◽  
Stress Treatment ◽  
Use Efficiency ◽  
Residual Transpiration

Increasing the water use efficiency (WUE) of wheat (Triticum spp.) has long been a goal in semiarid areas. Low rates of residual (cuticular) transpiration are thought to improve yield potential of wheat under dry conditions, although the linkage is tenuous. The objective of this work was to investigate the association of residual transpiration with water use, WUE, and leaf water status in hexaploid (T. aestivum L.) and tetraploid (T. turgidum L. var. durum) genotypes grown under two watering regimes in two glasshouse experiments. Single plants were grown in 0.1-m × 1-m (0.1-m × 0.5-m in exp. 2 low-stress treatment) PVC tubes filled with soil. The watering regimes consisted of weekly replenishment of water used (low stress), or addition of sufficient water to ensure plant survival (high stress). At anthesis, flag leaf residual transpiration (rate of water loss from excised leaves), stomatal conductance, relative water content (RWC), and osmotic potential (exp. 1 only) were measured. Water use was not correlated with residual transpiration rate in either experiment. Residual transpiration rate did not differ for the two stress treatments in exp. 1, but there were significant (P < 0.01) genotype by stress treatment interactions. Residual transpiration rate was not related to plant water status (leaf RWC or osmotic potential) as had been reported in other studies. Key words: Cuticular transpiration, water use efficiency, Triticum aestivum L., Triticum turgidum L. var. durum

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