Seed priming improves seedling emergence and reduces oxidative stress in Nigella sativa under soil moisture stress

2017 ◽  
Vol 41 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Sina Fallah ◽  
Somayeh Malekzadeh ◽  
Mohammad Pessarakli
Keyword(s):  
Oxidative Stress ◽  
Soil Moisture ◽  
Nigella Sativa ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Moisture Stress ◽  
Soil Moisture Stress

Influence of Soil Moisture, Temperature, and Compaction on the Germination and Emergence of Downy Brome (Bromus tectorum)

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 625-630 ◽  
Author(s):  
D. C. Thill ◽  
R. D. Schirman ◽  
A. P. Appleby
Keyword(s):  
Soil Moisture ◽  
Soil Compaction ◽  
Bromus Tectorum ◽  
Seedling Emergence ◽  
Moisture Stress ◽  
Soil Matric Potential ◽  
Downy Brome ◽  
Matric Potential ◽  
Soil Moisture Stress ◽  
Rate Of Emergence

The influence of soil moisture stress, temperature, and bulk density on the germination and seedling emergence of downy brome (Bromus tectorumL.) was investigated in the laboratory. Reductions in soil matric potential from -2 to -16 bars markedly reduced the percentage and rate of emergence. Seedling emergence was better at constant than at alternating temperatures. At high matric potentials, the rate of emergence was accelerated by warmer soil temperature (20 C), while at very low matric potentials, the percentage and rate of seedling emergence were least restricted at cooler temperatures (10 and 15 C). Soil matric potential did not influence the percentage or rate of emergence of seedlings grown from seed lots harvested during climatologically diverse years. Seedling emergence but not germination was inhibited by increased levels of soil compaction. Soil compaction times moisture interaction were not observed, as measured by final seedling emergence.

scholarly journals Improved understanding of drought controls on seasonal variation in Mediterranean forest canopy CO<sub>2</sub> and water fluxes through combined in situ measurements and ecosystem modelling

2009 ◽  
Vol 6 (8) ◽  
pp. 1423-1444 ◽  
Author(s):  
T. Keenan ◽  
R. García ◽  
A. D. Friend ◽  
S. Zaehle ◽  
C. Gracia ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Canopy ◽  
Moisture Stress ◽  
Mediterranean Ecosystems ◽  
Forest Growth ◽  
Water Fluxes ◽  
Soil Moisture Stress ◽  
Dynamic Global Vegetation Model ◽  
Forest Growth Model

Abstract. Water stress is a defining characteristic of Mediterranean ecosystems, and is likely to become more severe in the coming decades. Simulation models are key tools for making predictions, but our current understanding of how soil moisture controls ecosystem functioning is not sufficient to adequately constrain parameterisations. Canopy-scale flux data from four forest ecosystems with Mediterranean-type climates were used in order to analyse the physiological controls on carbon and water flues through the year. Significant non-stomatal limitations on photosynthesis were detected, along with lesser changes in the conductance-assimilation relationship. New model parameterisations were derived and implemented in two contrasting modelling approaches. The effectiveness of two models, one a dynamic global vegetation model ("ORCHIDEE"), and the other a forest growth model particularly developed for Mediterranean simulations ("GOTILWA+"), was assessed and modelled canopy responses to seasonal changes in soil moisture were analysed in comparison with in situ flux measurements. In contrast to commonly held assumptions, we find that changing the ratio of conductance to assimilation under natural, seasonally-developing, soil moisture stress is not sufficient to reproduce forest canopy CO2 and water fluxes. However, accurate predictions of both CO2 and water fluxes under all soil moisture levels encountered in the field are obtained if photosynthetic capacity is assumed to vary with soil moisture. This new parameterisation has important consequences for simulated responses of carbon and water fluxes to seasonal soil moisture stress, and should greatly improve our ability to anticipate future impacts of climate changes on the functioning of ecosystems in Mediterranean-type climates.

scholarly journals Erratum: Effect of soil moisture stress from flowering to grain maturity on functional properties of Sri Lankan rice flour

2011 ◽  
Vol 63 (6) ◽  
pp. 392-392 ◽  
Author(s):  
Anil Gunaratne ◽  
Upul Kumari Ratnayaka ◽  
Nihal Sirisena ◽  
Jennet Ratnayaka ◽  
Xiangli Kong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Functional Properties ◽  
Rice Flour ◽  
Moisture Stress ◽  
Sri Lankan ◽  
Soil Moisture Stress

The effects of soil moisture stress on the growth of barley. I. Vegetative development and grain yield

1964 ◽  
Vol 15 (5) ◽  
pp. 729 ◽  
Author(s):  
D Aspinall ◽  
PB Nicholls ◽  
LH May
Keyword(s):  
Grain Size ◽  
Soil Moisture ◽  
Grain Yield ◽  
Stem Elongation ◽  
Moisture Stress ◽  
The Other ◽  
Vegetative Development ◽  
Soil Moisture Stress ◽  
The One ◽  
Periods Of Stress

The effects of soil moisture stress on tillering, stem elongation, and grain yield of barley (cv. Prior) have been studied by subjecting the plants to periods of stress at different stages of development. Soil moisture stress treatments consisted of repeated short cycles of stress, single short cycles (both in large pots), or single long cycles (in large lysimeters). The data collected support the contention that the organ which is growing most rapidly at the time of a stress is the one most affected. Grain numbers per ear were seriously affected by stress occurring prior to anthesis, an effect probably associated with the process of spikelet initiation and, later, with the formation of the gametes. Grain size, on the other hand, was reduced more by stress at anthesis and shortly after. Elongation of the internodes was reduced mostly by stress at or just before earing, and was less seriously affected by earlier or later stress. Tillering, although being suppressed during a drought cycle, was actually stimulated upon rewatering. The effect was greater the earlier the period of stress, and was probably related to nutrient uptake and distribution within the plant.

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