Temporal changes in root growth and 15N uptake and water relations of two tussock grass species recovering from water stress

1992 ◽  
Vol 86 (4) ◽  
pp. 525-531 ◽  
Author(s):  
Hormoz BassiriRad ◽  
Martyn M. Caldwell
Keyword(s):  
Water Stress ◽  
Root Growth ◽  
Water Relations ◽  
Temporal Changes ◽  
Grass Species ◽  
15N Uptake ◽  
Tussock Grass

Root growth, appearance and disappearance in perennial grasses: Effects of the timing of water stress with or without defoliation

2002 ◽  
Vol 82 (3) ◽  
pp. 539-547 ◽  
Author(s):  
A. C. Flemmer ◽  
C. A. Busso ◽  
O. A. Fernandez ◽  
T. Montani
Keyword(s):  
Water Stress ◽  
Root Growth ◽  
Perennial Grass ◽  
Field Studies ◽  
Perennial Grasses ◽  
Grass Species ◽  
Phenological Stage ◽  
Semiarid Environments ◽  
Tussock Grasses ◽  
Different Levels

The effects of early and late defoliations were evaluated under different levels of soil water content on root growth, appearance and disappearance in Stipa clarazii Ball. S. tenuis Phil., and S. gynerioides Phil. Field studies were conducted in 1995. 1996 and early 1997. Stipa clarazii and S. tenuis are two important palatable perennial tussock grasses in temperate, semiarid rangelands of central Argentina. where S. gynerioides is one of the most abundant, unpalatable perennial grass species. We hypothesized that (1) root growth is reduced after defoliation at any phenological stage in S. clarazii and S. tenuis in comparison to undefoliated controls, (2) root growth. and root appearance and disappearance in all three species decrease as plant water stress increases, and (3) root growth associated with water stress in S. clarazii and S. tenuis is reduced comparatively less when plants are water-stressed earlier than later, or for a longer period of time during the growing season. Our results led us to reject hypothesis 1 and to accept hypotheses 2 and 3. Maintenance of root growth after defoliation in S. clarazii and S. tenuis would allow these species a greater soil exploration and resource finding to sustain regrowth in their native, semiarid environments. Key words: Root growth, appearance and disappearance, perennial grasses, water stress, defoliation, Stipa species

scholarly journals IRRIGATION, WATER RELATIONS, AND CRABAPPLE GROWTH IN ROOT-CONTROL BAGS IN A FIELD NURSERY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 632e-632
Author(s):  
Roger Kjelgren ◽  
Craig Spihlman
Keyword(s):  
Water Stress ◽  
Root Growth ◽  
Leaf Area ◽  
Water Relations ◽  
Production Cycle ◽  
Summer Drought ◽  
Silty Clay ◽  
Nursery Stock ◽  
Type Ii Errors ◽  
Silty Clay Soil

Limited root development of nursery stock in root-control bags facilitates harvest but without irrigation may predispose stock to water stress. The effect of bags and irrigation on growth and water relations of field-grown Malus sieboldii var. zumi were investigated following transplanting as large liners into a silty-clay soil. Predawn leaf water potential (ψ), and midday stomatal conductance (gs) and ψ, were measured periodically through the season. Late-season osmotic potential (ψπ), caliper, leaf area, and root growth were also measured. Non-irrigated treatments exhibited water stress during an extended mid-summer drought, as predawn ψ and particularly gs were less than irrigated treatments, resulting in lower vegetative growth and ψπ. For combined bagged treatments water relations did not differ, but leaf area, root growth, and ψπ, but not caliper, were less than non-bagged trees. Growth measurements and ψπ of non-irrigated bagged trees, however, were consistently lower but nonsignificant than the other treatments. Bag-induced root reduction can limit some top growth even with optimum soil water. Moreover, in terms of potential Type-II errors extrapolated over a conventional production cycle, trees grown in root-control bags in normally non-irrigated soils may be more susceptible to water stress and subjected to further cumulative growth limitation.

scholarly journals THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF SUGAR CANE (SACCHARUM OFFICINARUM): A REVIEW

2011 ◽  
Vol 47 (1) ◽  
pp. 1-25 ◽  
Author(s):  
M. K. V. CARR ◽  
J. W. KNOX
Keyword(s):  
Water Stress ◽  
Water Relations ◽  
Sugar Cane ◽  
Root Zone ◽  
Water Productivity ◽  
Crop Coefficient ◽  
Saccharum Officinarum ◽  
Irrigation Scheduling ◽  
Background Information ◽  
Technology Choice

SUMMARYThe results of research on the water relations and irrigation needs of sugar cane are collated and summarized in an attempt to link fundamental studies on crop physiology to irrigation practices. Background information on the centres of production of sugar cane is followed by reviews of (1) crop development, including roots; (2) plant water relations; (3) crop water requirements; (4) water productivity; (5) irrigation systems and (6) irrigation scheduling. The majority of the recent research published in the international literature has been conducted in Australia and southern Africa. Leaf/stem extension is a more sensitive indicator of the onset of water stress than stomatal conductance or photosynthesis. Possible mechanisms by which cultivars differ in their responses to drought have been described. Roots extend in depth at rates of 5–18 mm d−1 reaching maximum depths of > 4 m in ca. 300 d providing there are no physical restrictions. The Penman-Monteith equation and the USWB Class A pan both give good estimates of reference crop evapotranspiration (ETo). The corresponding values for the crop coefficient (Kc) are 0.4 (initial stage), 1.25 (peak season) and 0.75 (drying off phase). On an annual basis, the total water-use (ETc) is in the range 1100–1800 mm, with peak daily rates of 6–15 mm d−1. There is a linear relationship between cane/sucrose yields and actual evapotranspiration (ETc) over the season, with slopes of about 100 (cane) and 13 (sugar) kg (ha mm)−1 (but variable). Water stress during tillering need not result in a loss in yield because of compensatory growth on re-watering. Water can be withheld prior to harvest for periods of time up to the equivalent of twice the depth of available water in the root zone. As alternatives to traditional furrow irrigation, drag-line sprinklers and centre pivots have several advantages, such as allowing the application of small quantities of water at frequent intervals. Drip irrigation should only be contemplated when there are well-organized management systems in place. Methods for scheduling irrigation are summarized and the reasons for their limited uptake considered. In conclusion, the ‘drivers for change’, including the need for improved environmental protection, influencing technology choice if irrigated sugar cane production is to be sustainable are summarized.

scholarly journals Soil micro‐organisms and competitive ability of a tussock grass species in a dry ecosystem

2018 ◽  
Vol 107 (3) ◽  
pp. 1215-1225 ◽  
Author(s):  
Yudi M. Lozano ◽  
Sara Hortal ◽  
Cristina Armas ◽  
Francisco I. Pugnaire
Keyword(s):  
Competitive Ability ◽  
Grass Species ◽  
Tussock Grass ◽  
Micro Organisms

Adaptation to Water Stress of the Leaf Water Relations of Four Tropical Forage Species

1980 ◽  
Vol 7 (2) ◽  
pp. 207 ◽  
Author(s):  
JR Wilson ◽  
MM Ludlow ◽  
MJ Fisher ◽  
E Schulze
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Water Relations ◽  
Bound Water ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Panicum Maximum ◽  
Soil Drying ◽  
Buffel Grass ◽  
Heteropogon Contortus

Three tropical grasses, green panic (Panicum maximum var, trichoglume), spear grass (Heteropogon contortus) and buffel grass (Cenchrus ciliaris) and the tropical legume siratro (Macroptilium atropurpureum), were grown in plots in a semi-arid field environment. The water relations characteristics of leaves from plants subjected to a soil drying cycle were compared with those of unstressed leaves from plants in irrigated plots. Minimum water potentials attained in the stressed leaves were c. -44, - 38, - 33 and - 13 bar for the four species, respectively. The grass leaves adjusted osmotically to water stress, apparently through accumulation of solutes, so that there was a decrease in osmotic potential at full turgor (Ψπ100) of 5.5, 3.9 and 7.1 bar, and in water potential at zero turgor (Ψ0) of 8.6, 6.5 and 8.6 bar for green panic, spear grass and buffel respectively. Water stress appeared to increase slightly the proportion of bound water (B) and the bulk modulus of elasticity (ε) of the grass leaves, but it did not alter the relative water content at zero turgor (RWC0) or the ratio of turgid water content to dry weight of the tissue. The Ψπ100 and Ψ0 of stressed siratro leaves decreased by 2.5-4 bar and 3-5 bar respectively when subjected to soil drying cycles. These changes could be explained by the marked decrease in the ratio of turgid water content to dry weight of the leaf tissue rather than by accumulation of solutes. The values of RWC0 and ε for siratro leaves were not altered by stress but, in contrast to the grasses, B was apparently decreased although the data exhibited high variability. Adjustments in Ψπ100 and Ψ0 of stressed leaves of buffel grass and siratro were largely lost within 10 days of rewatering.

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