Sexual dimorphism in reproductive allocation and water use efficiency in Maireana pyramidata (Chenopodiaceae), a dioecious, semi-arid shrub

2003 ◽  
Vol 51 (5) ◽  
pp. 509 ◽  
Author(s):  
Andrea Leigh ◽  
Adrienne B. Nicotra

Sexual dimorphism in dioecious plant species is widely attributed to the differential impacts of reproduction on male v. female plants. We investigated sexual dimorphism in reproductive, morphological and physiological traits of Maireana pyramidata (Benth.) Paul G.Wilson (Chenopodiaceae), a dioecious, semi-arid shrub endemic to Australia. We estimated reproductive allocation for each sex by calculating the relative biomass allocated to flowers and fruits per gram of leaf tissue, based on one branch per sample plant. Morphological measurements included leaf mass, stem mass, specific leaf area, plant height and plant leaf area index. We also measured leaf nitrogen and chlorophyll, gas exchange and Δ13C. Reproductive allocation was nine times greater in females than in males. No significant difference between the sexes in photosynthetic rate or transpiration could be detected but instantaneous water use efficiency (photosynthesis/transpiration) was significantly lower in females than in males during the fruiting period. Δ13C did not differ between the sexes. The results indicate that greater reproductive allocation in females has an immediate impact on their capacity for conservative water use but does not lead to long-term differences in water use efficiency.

2019 ◽  
Vol 11 (3) ◽  
pp. 549
Author(s):  
Fábio Teixeira Delazari ◽  
Mariane Gonçalves Ferreira Copati ◽  
Gustavo Henrique da Silva ◽  
Ronaldo Silva Gomes ◽  
Derly José Henriques da Silva ◽  
...  

Nitrogen fertilization and supplying of water are crucial factors for quality and quantity produces of coriander. The objective of this study was to evaluate morphological and ecophysiological characteristics for coriander under five irrigation depths and two doses of nitrogen (N). Experimental layout was completely randomized design in a split plot scheme with five replications. The irrigation depths (plot) was 25, 50, 75, 100 and 125% of crop evapotranspiration (ETc). The doses of N (subplot) corresponded to 35 and 70 kg ha-1. The cultivation of coriander (“Vedete”) was in a protected environment. The ratio between the aerial part and roots linearly increased with the increment of the irrigation depths and was highest under 70 kg ha-1 of nitrogen. The leaf area index linearly increased with the increment of the irrigation depths at both doses of N. The leaf index of chlorophyll “a” was highest under irrigation depths of 87 and 75% of ETc for 35 and 70 kg ha-1 of N, respectively. The leaf index of chlorophyll “b” decrease linearly with the increase of irrigation depths in both doses of N. The nitrogen use efficiency was maximized with high soil moisture conditions. The water use efficiency decreases linearly with increasing of irrigation depth. The best irrigation depth and nitrogen dose obtained in this study was 125% of ETc and 70 kg/ha. The leaf index of chlorophyll “a” and “b” are important indicators of hydric stress. The leaf index of chlorophyll “b” are negatively correlated with leaf area index. N supply increase the water use efficiency.


Científica ◽  
2020 ◽  
Vol 48 (2) ◽  
pp. 85
Author(s):  
Wellington Mezzomo ◽  
Marcia Xavier Peiter ◽  
Adroaldo Dias Robaina ◽  
Jardel Henrique Kirchner ◽  
Rogério Ricalde Torres ◽  
...  

Author(s):  
Rômulo M. O. de Freitas ◽  
Jeferson L. D. Dombroski ◽  
Francisco C. L. de Freitas ◽  
Narjara W. Nogueira ◽  
Tiago S. Leite ◽  
...  

ABSTRACT The resilience of crops to drought depends heavily on the cultural practices adopted, which can have a direct effect on water use efficiency. The aim of this study was to assess the influence of irrigation intervals on the growth, water consumption and water use efficiency of cowpea crops (cv. BRS Guariba) under conventional and no-tillage systems. The experiment was carried out in the semi-arid region of Rio Grande do Norte, Brazil, using a split-plot in a randomised complete block design, with four replications. Treatments consisted of two cultivation systems in the whole plots (conventional and no-tillage) and six irrigation intervals in the subplots (2, 6, 10, 14, 18 and 22 days) which were applied at full bloom. The biomass of the different parts of the plant, leaf area and leaf area index were assessed at 64 days after sowing (DAS) and grain yield, water consumption and water use efficiency at 70 DAS. No-tillage is a promising cultivation technique for cowpea crops, promoting higher grain yield and water use efficiency under semi-arid conditions. This system allows cowpea cultivation with irrigation intervals of 10 or 14 days, with no or small reduction in yield, respectively.


1997 ◽  
Vol 24 (6) ◽  
pp. 831 ◽  
Author(s):  
Michael Battaglia ◽  
Peter Sands

A simple model, PROMOD, predicts the growth of a forest following canopy closure, i.e. under conditions in which the foliage biomass has attained a steady state. The principal output from PROMOD is peak mean annual increment. However, additional output available includes the closed-canopy leaf area index, evapotranspiration and water use efficiency. In addition, an indication of biomass partitioning around the time of peak MAI and the relative effects different environmental factors play in limiting production can be obtained. PROMOD is based on a generalisation of a simple forest growth model which predicts biomass production and partitioning at the stand level with a daily or annual time step. The minimum level of inputs required by PROMOD are of a quality and quantity that forest managers can readily and cheaply obtain for screening prospective plantation sites: the latitude, longitude, altitude, slope and aspect of the site and a classification of the soil depth, texture, stoniness, drainage and a rating of site fertility. However, PROMOD can be run using daily inputs of weather data and hence predict the seasonal variation of production. The closed-canopy leaf area index is calculated from the mean annual rainfall and temperature at the site, and a simple rating of site fertility. Annual production is calculated as the sum of daily production and takes diurnal temperature variation and possible seasonal photosynthetic acclimation into account. A simple soil water balance model is included in which water use is based on a crop factor which is a function of soil water content and a water use efficiency which is a function of vapour pressure deficit. The model was developed on the basis of data from nine plots of Eucalyptus globulus in south-eastern Tasmania and in Western Australia, and was validated using data from 19 plots in northern Tasmania.


2021 ◽  
Vol 13 (9) ◽  
pp. 48
Author(s):  
W. L. Zhang ◽  
J. R. Shao ◽  
L. Shen ◽  
T. T. Liu ◽  
Tayir Tohti ◽  
...  

In the semi-arid areas of Xinjiang in China, the agricultural community is facing long-term challenges in improving crop productivity and economic profits. A potential way to improve crop productivity is by intercropping food crops with cash crops. In this two-year field experimental study, we analyzed the advantages of the cumin/maize intercropping system as compared to cultivating them separately from three perspectives: crop growth, interspecific interactions, and water use efficiency. At the experimental site, each cropping systems (i.e., the cumin/maize intercropping system, monocropping cumin system, and monocropping maize system) had three replicates. In the experimental of 2019 and 2020, the three cropping systems showed significant differences in plant height, stem diameter, and leaf area index (LAI). The yields of the cumin/maize intercropping system were both lower than monocropping maize and cumin. However, the cumin/maize intercropping system had a higher land equivalent ratio (LER) than either of the monocropping systems, with a two-year average value of 1.65. Intercropped cumin was less dominant; as shown by aggressivity (Acm; averaging—0.22) and relative crowding coefficient (Rcm; averaging—3.15). In addition, the cumin/maize intercropping system significantly improved the Water equivalent ratio (WER) as compared to the monocropping systems, with a two-year average value of 1.67. Therefore, the cumin/maize intercropping system is a promising agricultural strategy to improve the utilization rate of agricultural resources and economic benefits in Xinjiang.


2018 ◽  
Vol 5 (10) ◽  
pp. 537-548
Author(s):  
Belhaj Mguidiche Amel ◽  
Boutheina Douh ◽  
Kalthoum Harbaoui

Improvement of water use efficiency (WUE) in wheat is important for almost all agricultural practices, so Water use efficiency (WUE), is the ratio of grain yield to crop water use, provides a simple means of assessing whether yield is limited by water supply or other factors. Limited precipitation restricts yield of wheat grown in Tunisia, so supplement irrigation will be paramount in Mediterranean agriculture in the future where wheat is a major crop. The present study was carried out in two stations of the Regional Filed Crop Research Center of Béja, Tunisia, in sub humid climatic stage and Oued Miliz in semi arid, in sub humid experiment was conducted rainfed whereas three irrigations levels were used in semi arid condition. The aim of this work was to study effect of biocliamtic stage and supplemental irrigation on yield and water use efficiency. There was a significant difference (p < 0.05) in biological water use efficiency between two climatic stages for all varieties; whereas in the same condition there no significant difference between varieties.


Author(s):  
Jiying Sun ◽  
Julin Gao ◽  
Zhigang Wang ◽  
Shuping Hu ◽  
Fengjie Zhang ◽  
...  

Subsoil tillage loosens compacted soil for better plant growth, but promotes water loss, which is a concern in areas commonly irrigated. Therefore, our objective was to determine the physiological responses of high yield spring corn (Zea mays L.) to Subsoil tillage depth when grown in the western plain irrigation area of Inner Mongolia that leads to the best water use efficiency. The experiment during 2014 and 2015 used Zhengdan958 and Xianyu335 with three differing subsoil tillage depths (30, 40, or 50 cm) as trial factor and shallow rotary as a control. Subsoil tillage increased shoot dry matter accumulation, leading to a greater shoot/root ratio. Subsoil tillage helped retain greater leaf area index in each growth stage, increase the leaf area duration, net assimilation rate, and relative growth rate, with greater effects as tillage was deeper, effectively delaying the aging of the blade. Grain yields were increased by 0.7%&ndash;8.9% on average in subsoil tillage treatments compared to conventional soil treatment shallow rotary, Water use efficiency were increased by 1.93%&ndash;18.49% on average in subsoil tillage treatment compared to shallow rotary, resulting in net income increases by 2.24% to 6.97% compared to shallow rotary. Among the three different subsoil tillage depth treatment, the grain yield, water use efficiency, and net income is the best under the treatment of subsoil tillage depth of 50 cm.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  

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.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 466
Author(s):  
Qibo Tao ◽  
Mengjie Bai ◽  
Cunzhi Jia ◽  
Yunhua Han ◽  
Yanrong Wang

Irrigation and nitrogen (N) are two crucial factors affecting perennial grass seed production. To investigate the effects of irrigation and N rate on seed yield (SY), yield components, and water use efficiency (WUE) of Cleistogenes songorica (Roshevitz) Ohwi, an ecologically significant perennial grass, a four-year (2016–2019) field trial was conducted in an arid region of northwestern China. Two irrigation regimes (I1 treatment: irrigation at tillering stage; I2 treatment: irrigation at tillering, spikelet initiation, and early flowering stages) and four N rates (0, 60, 120, 180 kg ha−1) were arranged. Increasing amounts of both irrigation and N improved SY, evapotranspiration, WUE, and related yield components like fertile tillers m−2 (FTSM) and seeds spikelet−1. Meanwhile, no significant difference was observed between 120 and 180 kg N ha−1 treatments for most variables. The highest SY and WUE was obtained with treatment combination of I2 plus 120 kg N ha−1 with four-year average values of 507.3 kg ha−1 and 1.8 kg ha−1 mm−1, respectively. Path coefficient and contribution analysis indicated that FTSM was the most important yield component for SY, with direct path coefficient and contribution coefficient of 0.626 and 0.592. Overall, we recommend I2 treatment (three irrigations) together with 120 kg N ha−1 to both increase SY and WUE, especially in arid regions. Future agronomic managements and breeding programs for seed should mainly focus on FTSM. This study will enable grass seed producers, plant breeders, and government program directors to more effectively target higher SY of C. songorica.


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