The effects of soil moisture stress on the growth of barley. II. Grain growth

1965 ◽  
Vol 16 (3) ◽  
pp. 265 ◽  
Author(s):  
D Aspinall

The influence of water stress on grain growth has been investigated under conditions of intermittent stress with pot-grown plants and under longer periods of stress with plants grown in lysimeters. Premature cessation of growth was induced by even a moderate water stress, but the rate of grain growth (in dry weight) in the early stages of development was reduced only by severe water stress. There was evidence for an actual loss of dry matter in the final stages of maturation where plants were subjected to severe water stress. Grain moisture content was relatively unaffected by water stress during the major period of grain development, although grain water content dropped with increasing water stress during ripening. Spikelet chlorophyll content was also reduced by water stress, particularly in the later stages of grain development. Indirect evidence indicated that translocation of assimilate from the leaves to the ear was reduced by a moderate water stress. Tne significance of these findings in elucidating the mechanism of action of water stress on grain growth is discussed.

Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 106-108 ◽  
Author(s):  
David D. Briske ◽  
Bennie J. Camp

The influence of water stress on toxic alkaloid concentrations in threadleaf groundsel (Senecio longilobus Benth.) was investigated in a controlled environment by monitoring leaf xylem water potential during a 32-day period, and then analyzing for alkaloid concentration by plant part. Total plant alkaloid concentration increased with increasing severity of water stress. The most severe water stress (−2.0 MPa) for the 32-day period increased alkaloid concentration by 4.6 times, compared to the least stress imposition (−1.0 MPa). Averaged across watering regimes, alkaloid concentrations (percent dry weight) were highest in threadleaf groundsel roots (0.088%) and occurred in similar concentrations in stems (0.046%) and leaves (0.050%). These results indicate the importance of considering the influence of plant water stress when investigating secondary plant compounds.


1977 ◽  
Vol 4 (5) ◽  
pp. 799 ◽  
Author(s):  
I Sofield ◽  
IF Wardlaw ◽  
LT Evans ◽  
SY Zee

Plants of five cultivars of wheat were grown under controlled-environmental conditions in order to analyse the effect of cultivar and of temperature and illuminance after anthesis on the accumulation of nitrogen and phosphorus by grains in relation to dry matter. The water relations of the grain during maturation were also examined, using calcium content as an index of water entry. The nitrogen and phosphorus contents of grains increased linearly throughout the grain growth period. The percentage of nitrogen and phosphorus in grains fell sharply during the first few days after anthesis but rose progressively thereafter. The higher the temperature, and the lower the illuminance, the higher was the percentage of nitrogen in the grain of all cultivars. Such conditions also reduce final grain size, but their effects on nitrogen concentration in the grain were apparent early in grain development. No evidence was found of a flush of nitrogen or phosphorus into the grain late in its development. Water entry into the grain continued at a steady rate until maximum grain dry weight was reached, then ceased suddenly. No evidence was found of an increased rate of water loss by the grain at that stage, and the rapid fall in water content at the cessation of grain growth may have been due to blockage of the chalazal zone of entry into the grain by the deposition of lipids. Accumulation of dry matter, nitrogen and phosphorus and entry of water into the grain all ceased at the time of lipid deposition in the chalazal zone.


Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 322
Author(s):  
Yong-Zhong Luo ◽  
Guang Li ◽  
Guijun Yan ◽  
Hui Liu ◽  
Neil C. Turner

Drought is one of the major abiotic stresses affecting the morphological, physiological, and metabolic processes of plants, and hence their growth and production on a global scale. Lucerne (Medicago sativa L.) is one of the most popular pasture species in semi-arid regions and plays a critical role in sustaining agricultural systems in many areas of the world. In order to evaluate the effect of water deficits on the growth and biomass distribution in different tissues of lucerne, plant height, leaf dry weight, leaf number and area, root dry weight, taproot length and lateral root number, and stem dry weight were measured at four stages from the seedling to flowering stages under three water regimes: (i) adequate water supply (minimum soil water content 85% pot capacity (PC)), (ii) moderate water stress (65% PC), and (iii) severe water stress (45% PC), imposed under a rainout shelter. With limited water supply, plant height, leaf number, leaf area and dry weight, taproot length, and total biomass were reduced, while lateral root numbers increased. The number of smaller leaves and root dry weight increased under moderate water stress, whereas severe water stress reduced them. Leaf, stem, and total dry weight were all reduced by the water deficits, but leaf dry weight was reduced the most and root dry weight the least, so there was a redistribution of biomass towards the roots, increasing the root–shoot ratio. These results help us to understand the response of lucerce to water stress and assist in developing a foundation for the sustainable use of lucerne in semi-arid agricultural systems.


2008 ◽  
Vol 20 (1) ◽  
pp. 29-37 ◽  
Author(s):  
José Beltrano ◽  
Marta G. Ronco

The aim of this paper was to investigate the contribution of the arbuscular mycorrhizal fungus Glomus claroideum to drought stress tolerance in wheat plants grown under controlled conditions in a growth chamber, and subjected to moderate or severe water stress and rewatering. Water stress tolerance was determined through total dry weight, leaf relative water content, leakage of solutes and leaf chlorophyll and protein concentrations in mycorrhizal and non-mycorrhizal wheat plants. Total dry weight and leaf chlorophyll concentrations were significantly higher in mycorrhizal plants after moderate or severe water stress treatments compared with non-mycorrhizal ones. Electrolyte leakage was significantly lower in water-stressed inoculated plants. Compared to non-inoculated plants, leaf relative water content and total protein concentration of inoculated individuals increased only under severe water stress. When irrigation was re-established, mycorrhizal plants increased their total dry weight and leaf chlorophyll concentration, and recovered cell membrane permeability in leaves compared with non-mycorrhizal plants. In conclusion, root colonization by G. claroideum could be an adequate strategy to alleviate the deleterious effects of drought stress and retard the senescence syndrome in wheat.


2020 ◽  
Author(s):  
Dipika S. Patel ◽  
Bardhan Kirti ◽  
P Patel Dhiraji ◽  
Parekh Vipulkumar ◽  
Jena Suchismita ◽  
...  

ABSTRACTThe root is the sensing organ for potassium (K) and water availability. We evaluated whether K availability influences root architecture and contributes to drought tolerance under moisture stress. Rice seedling growth was severely affected by low K availability under water stress, and the substantial reductions in root projected area, maximum width, and width to depth ratio were observed. High K availability helps maintain root top and bottom angles and reduces root steepness under mild water stress, but over K nutrition does not ensure higher seedling growth. Under severe water stress, the steepness was more regulated by water than K availability.


2014 ◽  
Vol 76 ◽  
pp. 183-188
Author(s):  
Keith Widdup ◽  
Shirley Nichols ◽  
Warren Williams ◽  
Isabelle Verry ◽  
Ben Harvey

Abstract White clover (Trifolium repens L.) is valued for its contribution to pasture quality and utilisation by animals, compatibility with grass, and fixation of nitrogen. However, it is limited by poor adaptation to drought. Hybridisation with Trifolium uniflorum L. may have potential to improve the drought resistance of white clover. An experiment in a rain shelter facility with contrasting moisture treatments, and a field evaluation under dryland conditions, were used to compare the agronomic potential of these interspecific hybrids (ISH) with white clover in moisture limited conditions. In the rain shelter experiment, there were smaller effects of water stress on shoot dry weight (DW), leaf area, internode length and senescence of first backcross generation hybrids compared with white clover and second backcross generation hybrids. Differences in photosynthetic responses were possibly influenced by the effect of root DW allocation on water uptake. In the field evaluation, growth scores of a wider range of hybrid families during summer moisture stress concurred with the results under water stress in the rain shelter. Growth of some ISH families outperformed the best white clover cultivars, particularly in the third and most stressful summer and this result was a key performance indicator of the value of the hybrids for drought prone areas. These findings using early, unselected, hybrid populations indicate the potential for further selection of elite, adapted cultivars from ISH breeding strategies. Keywords: Interspecific clover hybrid, drought resistance, rain shelter, field evaluation


1979 ◽  
Vol 30 (1) ◽  
pp. 1 ◽  
Author(s):  
IL Gordon ◽  
LN Balaam ◽  
NF Derera

Examination of grain development in two white-grained (non-dormant) and two red-grained (varying dormancy) wheat genotypes has clarified concepts of maturity with respect to grain dehydration, harvest ripeness, embryo maturity, base α-amylase activity and dry weight growth. Each maturity trait had a different pattern of development. The net level of grain maturity at harvest ripeness depended on the relative progress of the maturation traits at the time at which harvest ripeness was defined. Harvest ripeness is defined as the first attainment of 12½% moisture during primary dehydration of the grain, this being closely related to fitness for harvest. The effects of adopting other definitions of harvest ripeness (at 17½% and 20% grain moisture) are discussed. Significant differences amongst genotypes in development patterns, temporal placement, and harvest ripeness level were found in each maturity trait, and the differences were not parallel across traits. Differences in maturation did not coincide with differences in putative dormancy or grain colour. Results indicated that grain maturation was a multi-faceted process, with flexible synchronizations amongst maturation traits at any point in time, such as at harvest ripeness. Germination tests or a-amylase assays on progeny grain samples, at some time after harvest ripeness, measure differences in maturity as well as putative differences in dormancy. Interpretation only in terms of dormancy could be misleading. Adjustment for immaturity is discussed. ____________________ *Part I, Aust. J. Agric. Res., 28: 583 (1977).


2016 ◽  
Vol 27 (3) ◽  
pp. 265-271
Author(s):  
MA Khaton ◽  
A Sagar ◽  
JE Tajkia ◽  
MS Islam ◽  
MS Mahmud ◽  
...  

Drought adversely affects growth and yield of crops to various extents. Growing of drought tolerant crops is a good option to obtain economical yields from water stress areas for which quick method to screen drought tolerant plants, particularly in early stages of their growth is important. For this reason, a field experiment was conducted to evaluate the genetical potential to drought tolerance of four sorghum varieties viz Hybrid Sorgo, Safal, BD 731, BD 740. The experiment was laid out in a split plot design with three replications. The plants were grown under three drought levels viz. 100% FC (control), 70% FC and 40% FC. Growth and yield of the Sorghum varieties were found to be decreased gradually with gradual increase in drought levels as compared to the control. This reduction was associated with decreased yield components. Water stress also decreased protein and starch content. The variety BD 740 followed by BD 731 showed the better performance in respect of no. of grains panicle-1, panicle dry weight, 1000-grain weight, grain yield hill-1, protein content and starch content than Hybrid Sorgo and Safal at same water stress condition. Therefore Bangladeshi varieties were found more tolerant than Hybrid Sorgo variety to water stress. Findings of this research will be helpful for the farmers about the beneficial use of resource in terms of managing limited water as well as increasing crop productivity. Finally these research findings would certainly contribute food security in Bangladesh.Progressive Agriculture 27 (3): 265-271, 2016


1972 ◽  
Vol 50 (12) ◽  
pp. 2411-2418 ◽  
Author(s):  
Russell T. Moore ◽  
Richard S. Whiter ◽  
Martyn M. Caldwell

Atriplex confertifolia and Eurotia lanata plants were studied in the field and laboratory under controlled conditions of temperature and vapor pressure deficit with uniform wind speed and light intensity and various levels of water stress. Multiple regression analysis indicated that under both field and laboratory conditions, vapor pressure deficit and water stress were significant factors influencing transpiration. Phenological stage was also a major factor in the transpirational relationships of both species in the field. Transpiration rates under comparable conditions tended to be higher for Eurotia than for Atriplex on a leaf dry weight basis with less pronounced differences on a leaf area basis. However, in the latter part of the summer, transpiration rates of Eurotia decreased markedly while Atriplex tended to maintain active transpiration. Under laboratory conditions both species exhibited transpiration at plant moisture stress values as great as 115 bars.


2019 ◽  
Vol 22 (2) ◽  
pp. 23-30
Author(s):  
KP Halder ◽  
MS Islam ◽  
MR Manir ◽  
MA Ali

The experiment was conducted at the Bangladesh Rice Research Institute (BRRI) Gazipur farm during Boro 2003-04 seasons to observe the moisture stress effects in relation to nutrient rates on growth and yield of rice. The treatments were three moisture stresses (NS= Always saturated condition i.e. 1-2 cm standing water; VPS= Withholding water at the vegetative phase i.e. 15 days after transplanting (DAT) to maximum tillering stage; RPS=Withholding water at the reproductive phase i.e. PI to flowering stage) and three fertilizer doses (F0= No fertilizer; HD= Half of the optimum dose and OD= Optimum dose i.e. 120-60-40-10-2 kg ha-1 of N, P2O5, K2O, S and Zn respectively). The treatments were applied in high yielding variety BRRI dhan29. The result showed that irrespective of nutrient rates, drought stress decreased plant height, tiller number and shoot dry weight. Unstressed plants (NS) produced the highest grain yield (3.14 to 6.51 tha-1) followed by vegetative phase stressed (VPS) plants (2.73 to 4.50 tha-1). The reproductive phase stressed (RPS) plants produced the lowest grain yield (2.54 to 4.20 t ha-1). Regardless of water stress, application of optimum dose (OD) of nutrients produced the highest grain yield followed by half dose (HD) of nutrients. No fertilizer treatment (F0) produced the lowest grain yield. Due to water stress, the highest grain yield reduction occurred in OD (22-32%) followed by HD (12-19%) and the lowest in F0 (4-15%). Bangladesh Rice j. 2018, 22(2): 23-30


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