scholarly journals Water use efficiency of cassava plants under competition conditions

2010 ◽  
Vol 28 (4) ◽  
pp. 699-703 ◽  
Author(s):  
I Aspiazú ◽  
T Sediyama ◽  
J.I Ribeiro Jr ◽  
A.A Silva ◽  
G Concenco ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Activity ◽  
Water Status ◽  
Weed Species ◽  
Fiber Glass ◽  
Bidens Pilosa ◽  
Commelina Benghalensis ◽  
Use Efficiency ◽  
Experimental Level

The objective of this work was to evaluate characteristics associated with the photosynthetic activity of cassava plants in competition with weeds or not. The trial was performed on open environment conditions, with experimental units consisting of fiber glass vases with 150 dm³ filled with Red Yellow Latosol, previously fertilized. Treatments consisted in the cultivation of cassava plants isolated and associated to three weed species (Bidens pilosa, Commelina benghalensis and Brachiaria plantaginea). After cassava shooting, 15 days after planting, a removal of the weeds excess was performed, sown at the time of cassava planting, leaving six plants m-2 of B. pilosa and four plants m-2 of C. benghalensis and B. plantaginea. At 60 days after emergence (DAE), stomatal conductance (Gs), vapor pressure in the substomatal cavity (Ean), temperature gradient between leaf and air (ΔT), transpiration rate (E) and water use efficiency (WUE) were evaluated. B. pilosa showed greater capacity to affect growth of cassava plants. B. plantaginea is very efficient in using water, especially by presenting C4 metabolism, and remains competitive with cassava even under temporarily low water status. C. benghalensis, in turn, is not a good competitor for light and apparently is not the primary cause of water depletion in the soil. The effects of weeds, in this case, were more associated with the competition. However, they were found between moderate to low. This implies that the competition established at experimental level was low.

scholarly journals Physiology of Weeds in Intraspecific Competition

2018 ◽  
Vol 10 (6) ◽  
pp. 334
Author(s):  
Caroline Hernke Thiel ◽  
Felipe Adelio de David ◽  
Leandro Galon ◽  
Sidnei Deuner ◽  
Cesar Tiago Forte ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Intraspecific Competition ◽  
Plant Density ◽  
Block Design ◽  
Morning Glory ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Use Efficiency ◽  
Hairy Fleabane

When plants are subjected to competition, their physiological behavior changes. To understand the developmental physiology of weeds will subsidize the development of cropping systems which favor the crops plants in detriment of weeds. The objective of this work was to evaluate the physiological behavior of different weed species, growing under intraspecific competition. Greenhouse experiment was conducted in randomized complete block design arranged in factorial scheme 4 × 5 with four replications. Factor A was the weed species [Urochloa plantaginea (Alexandrergrass), Bidens pilosa (hairy beggarticks), Ipomoea indivisa (morningglory) and Conyza bonariensis (hairy fleabane)], and factor B was the plant density of these species (20, 40, 60, 80 or 100 plants m-2). The following variables were evaluated: sub-stomatal CO2 concentration, photosynthesis rate, consumed CO2, stomatal conductance, transpiration rate, water use efficiency, plant height, shoot diameter, leaf area, and shoot dry biomass. Alexandergrass relies on the superior control of stomatal opening and high water use efficiency. Hairy beggarticks efficiency in competition lies on its ability to remove water from soil to levels when the other surrounding plant species would undergo stress. Morning glory and hairy fleabane did not present detectable particular features in the study, and their importance as weeds is probably tied to other survival abilities but superior competition. In conclusion, the weed species studied present distinct competitive strategies.

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

Effect of irrigation and defoliation on the herbage production and water use efficiency of four temperate pasture species

1973 ◽  
Vol 24 (6) ◽  
pp. 797 ◽  
Author(s):  
GG Johns ◽  
A Lazenby
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Water Status ◽  
The Other ◽  
Use Efficiency ◽  
Water Use Efficiencies ◽  
Similar Quantity

Measurements were made over a 12-month period of the herbage production of both dryland and irrigated monoculture swards of four temperate pasture species under two defoliation regimes. By relating herbage production to the previously reported water use results for these swards, water use efficiencies (WUE) have been computed. Dryland clover produced 2000 kg/ha less herbage than did the dryland grasses, although it used a similar quantity of water. Consequently, the WUE of dryland clover was substantially less than that of the dryland grasses. Under dryland conditions, fescue not only produced more herbage, but also used water more efficiently than did the other species. Similar amounts of irrigation enabled the clover to yield an extra 6000 kg/ha of herbage compared with a mean grass response of 1760 kg/ha. The irrigated clover swards generally used water much more efficiently than the dryland clover swards. In contrast, the grasses generally used water with similar efficiency under both irrigated and dryland conditions. Under both irrigated and dryland conditions the frequently defoliated swards usually outyielded those cut infrequently as well as making more efficient use of water. The response of pastures to irrigation is discussed in terms of the effects of irrigation on the water status of the plants and the availability of nutrients in the rhizosphere.

Overexpression of an aquaporin gene PvPIP2;9 increased leaf length, improved drought tolerance and water use efficiency and affected other PIP2 genes’ expression in switchgrass (Panicum virgatum L.)

2019 ◽  
Author(s):  
Jing Zhang ◽  
Wuwu Wen ◽  
Hui Li ◽  
Qiyu Lu ◽  
Bin Xu ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Panicum Virgatum ◽  
Water Status ◽  
Expression Patterns ◽  
Water Withdrawal ◽  
Water Transportation ◽  
Aquaporin Gene ◽  
Use Efficiency

Abstract Background: Switchgrass (Panicum virgatum L.) is a prime candidate for non-grain-based bioenergy feedstock production. Improved the drought tolerance and higher water use efficiency are important traits for its successful field establishment and production especially in marginal land. Aquaporins are key channels and regulators for water transportation and maintenance of cellular water status. In this study, the functional role of an aquaporin gene, PvPIP2;9, in switchgrass drought tolerance was studied.Results: Expression of PvPIP2;9 was regulated by the diurnal oscillation and osmotic stress. Constitutive over-expressing PvPIP2;9 in switchgrass significantly improved its drought tolerance and water use efficiency with less electrolyte leakage rates but higher relative water contents, photochemical efficiencies, and chlorophyll contents. Moreover, expression patterns of all 14 switchgrass PIP2 subfamily genes were checked in wildtype and transgenic plants during the water-withdrawal treatment, and the result showed that over-expressing PvPIP2;9 also affected transcript levels of most other PIP2 genes. Conclusions: Together, this study showed that improved drought tolerance and higher water use efficiency can be achieved by manipulating the expression level of PvPIP2;9 and also suggested PIP2 subfamily genes were transcriptionally regulated in a coordinated manner.

scholarly journals Acidified Biochar as a Soil Amendment to Drought Stressed (Vicia faba L.) Plants: Influences on Growth and Productivity, Nutrient Status, and Water Use Efficiency

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1290
Author(s):  
Taia A. Abd El-Mageed ◽  
Eman E. Belal ◽  
Mohamed O. A. Rady ◽  
Shimaa A. Abd El-Mageed ◽  
Elsayed Mansour ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Properties ◽  
Water Use ◽  
Seed Yield ◽  
Soil Amendment ◽  
Field Experiments ◽  
Water Status ◽  
Water Productivity ◽  
Crop Productivity ◽  
Use Efficiency

Drought is one of the major threats to global food security. Biochar use in agriculture has received much attention and improving it through chemical modification offers a potential approach for enhancing crop productivity. There is still limited knowledge on how acidified biochar influences soil properties, and consequently its influences on the agricultural productivity of drought stressed plants. The water use efficiency (I-WUE) of drought stressed faba beans was investigated through the effects of acidified biochar (ACBio) (a 3:100 (w:w) combination of citric acid and biochar) on soil properties, growth, productivity, nutrient uptake, water productivity (WP), and irrigation. Two field experiments (2016/2017 and 2017/2018) were conducted in saline soil (ECe, 7.2 dS m−1) on faba been plants grown under three irrigation regimes (i.e., 100, 80, and 60% of crop evapotranspiration (ETc)) combined with three levels of ACBio (0, 5, and 10 t ha−1). Plants exposed to water stress presented a significant decrease in plant height, dry matter, leave area, chlorophyll content (SPAD), the quantum efficiency of photosystem II (Fv/Fm, Fv/F0, and PI), water status (membrane stability index and relative water content), and seed yield. Acidified biochar soil incorporation improved soil properties (chemical and physical), plant growth, physiological responses, WP, I-WUE, and contents of N, P, K, and Ca. Results revealed that the application of ACBio at 10 t ha−1 and 5 t ha−1 significantly increased seed yield by 38.7 and 25.8%, respectively, compared to the control. Therefore, ACBio incorporation may find application in the future as a potential soil amendment for improving growth and productivity of faba bean plants under deficit irrigation.

scholarly journals Effect of Nutrient Supply on Some Selected Parameters of Sweet Pepper (Capsicum annuum L. cv. ‘HRF’) Transplants

2016 ◽  
Vol 64 (2) ◽  
pp. 455-460
Author(s):  
Aleš Jezdinský ◽  
Robert Pokluda ◽  
Katalin Slezák
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Activity ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Sweet Pepper ◽  
Control Treatment ◽  
Average Value ◽  
Use Efficiency

In the trial the effect of nitrogen deficiency and potassium surplus on the dry weight, photosynthetic activity (A), transpiration (E), stomatal conductance (gs) and water use efficiency (WUE) were examined. The macroelement content of aboveground parts were analysed, too. The plants were grown in pots filled by pure Sphagnum peat. The top-dressing started in the 3-leave stage of plants, with different solution (every irrigation): control treatment: 0.28 g N, 0.097 g P (0.22 g P2O5), 0.42 g K (0.50 g K2O) per litre; nitrogen-deficiency: 0.097 g P (0.22 g P2O5), 0.42 g K (0.50 g K2O) per litre; potassium surplus: 0.28 g N, 0.097 g P (0.22 g P2O5), 0.83 g K (1.0 g K2O) per litre. The transplants grown in the commercial fertilization technology (control treatment) almost in every evaluated parameters shown average value. The potassium surplus resulted significantly higher transpiration activity (2.58 mmol H2O. m−2. s−1) and photosynthetic activity (11.54 μmol CO2. m−2. s−1) than the nitrogen deficiency (E: 1.91 mmol H2O. m−2. s−1and A: 9.01 μmol CO2. m−2. s−1), but without significant differences with control treatment. The N, P and K content of aboveground parts was significantly lower in the nitrogen deficiency treatment, than in the case of the potassium surplus, too. The effect of treatments on the dry weight of the plants, the stomatal conductance and the water use efficiency was not proven statistically.

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