`Ben Lear' and `Stevens' Cranberry Root and Shoot Growth Response to Soil Water Potential

Wisconsin cranberry growers report that fruit production by the cranberry cultivar `Ben Lear' (Vaccinium macrocarpon Ait.) is low in beds with poor drainage, while the cultivar `Stevens' is less sensitive to these conditions. We hypothesized that `Ben Lear' and `Stevens' would differ in their root growth and mortality response to variation in soil water potential. Rooted cuttings of each cultivar were grown in a green-house in sand-filled pots with three different soil water potentials which were regulated by a hanging water column below a fritted ceramic plate. A minirhizotron camera was used to record root growth and mortality weekly for five weeks. Root mortality was negligible (2% to 6%). Whole plant relative growth rates were greatest for both cultivars under the wettest conditions. Rooting depth was shallowest under the wettest conditions. Whole-plant relative growth rates of `Ben Lear' were higher than `Stevens' at all soil water potentials. `Stevens' plants had significantly higher root to shoot ratios and lower leaf area ratios than `Ben Lear' plants, and produced more total root length than `Ben Lear' at all soil water potentials. Shallow rooting, high leaf area ratio, and low allocation to root production by `Ben Lear' plants may lead to greater susceptibility to drought stress than `Stevens' plants in poorly drained cranberry beds.

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Influence of soil water potential and mycorrhizal colonization on root growth of yellow-poplar and sweet gum seedlings grown in compacted soil

Canadian Journal of Forest Research ◽

10.1139/x88-217 ◽

1988 ◽

Vol 18 (11) ◽

pp. 1392-1396 ◽

Cited By ~ 11

Author(s):

G. L. Simmons ◽

P. E. Pope

Keyword(s):

Root Growth ◽

Water Potential ◽

Bulk Density ◽

Soil Water ◽

Root Length ◽

Soil Water Potential ◽

Mechanical Resistance ◽

Yellow Poplar ◽

Greenhouse Study ◽

Water Potentials

A greenhouse study was conducted to determine the influence of soil water potential and endomycorrhizal fungi on root growth of yellow-poplar (Liriodendrontulipifera L.) and sweet gum (Liquidambarstyraciflua L.) seedlings grown at three soil bulk densities. Silt loam soil was compacted in PVC pots to bulk densities of 1.25 (low), 1.40 (medium), or 1.55 (high) Mg • m−3, and equilibrated at −10 kPa soil water potential. Newly germinated seedlings were transplanted into the pots, inoculated with fungal chlamydospores of Glomusmacrocarpum or Glomusfasciculaturn, or distilled water (control), and grown for 3 months at −10 or −300 kPa soil water potential. Total porosity, air-filled porosity, water content, and mechanical resistance of the soil were determined for samples compacted to the same bulk densities and equilibrated at the same soil water potentials as were used in the greenhouse study. Root growth was reduced by the high mechanical resistance caused by bulk densities of 1.40 and 1.55 Mg • m−3 at −300 kPa water potential. At both water potentials, total length of lateral roots and fibrosity of the root system of both tree species decreased significantly when bulk density increased from 1.40 to 1.55 Mg • m−3. Air-filled porosity less than 0.12 m3 • m−3 limited root growth when water potential was −10 kPa, and mechanical resistance greater than 3438 kPa restricted growth at −300 kPa. At −10 kPa, root length and fibrosity were greatest for inoculated sweet gum seedlings at each bulk density. At −300 kPa, sweet gum seedlings inoculated with G. fasciculatum had the greatest root length and fibrosity at the low and medium bulk densities. Mycorrhizal effects on root length of yellow-poplar were variable, and fibrosity was not significantly affected by mycorrhizal treatment.

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Physiological responses of semiarid grasses. III.* Growth in relation to temperature and soil water deficit

Australian Journal of Agricultural Research ◽

10.1071/ar9750447 ◽

1975 ◽

Vol 26 (3) ◽

pp. 447 ◽

Cited By ~ 5

Author(s):

EK Christie

Keyword(s):

Soil Water ◽

Growth Rates ◽

Soil Water Potential ◽

Dry Weight ◽

Phosphorus Concentration ◽

Relative Growth ◽

Relative Growth Rates ◽

Ample Supply ◽

Net Assimilation ◽

Tissue Phosphorus

The optimum temperature for vegetative growth of mulga grass was about 25°C, and for Mitchell and buffel grasses 30°. Buffel grass had the highest yield at all temperatures, partly because of its higher growth rate which in turn can be ascribed to both a higher net assimilation rate and the diversion of a greater proportion of dry weight into leaf area. Seedlings with an ample supply of phosphate had higher relative growth rates than phosphorus-deficient seedlings at the commencement of the soil drying cycle, but their growth rates declined more rapidly as the soil water potential fell. This decline was associated with a reduction in the rate of phosphate absorption as well as a decrease in the tissue phosphorus concentration. *Part II, Aust. J. Agric. Res., 26: 437 (1975).

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Maize nodal root growth under water deficits

10.32469/10355/62393 ◽

2016 ◽

Author(s):

◽

Kara J. Riggs

Keyword(s):

Root Growth ◽

Water Potential ◽

Root System ◽

Soil Water ◽

Soil Water Potential ◽

Experimental System ◽

Root Tip ◽

Growth Responses ◽

Water Potentials ◽

Nodal Root

The nodal root system is critical for the development of the mature root system in maize (Zea mays L.) and other grasses. Under drought conditions, nodal root axes may need to grow through surface soil that is dry, hard, and hot. These roots are known to have a superior ability to continue elongation at low water potentials relative to other organs of the plant, but the physiology of this response has been little studied. The objective of this study was to develop an experimental system that models the field situation in which upper soil layers dry, to enable studies of nodal root growth regulation under water deficit conditions. A divided-chamber experimental system was developed to allow the growth of maize primary and seminal root systems in well-watered conditions while the nodal root system is exposed to precise conditions of low soil water potential. The divided-chamber system was used to characterize nodal root growth responses to a range of soil water potentials under steady-state and reproducible conditions. Two contrasting genotypes, selected for differences in root growth response to water stress based on a previous study of the primary root, displayed similarly sensitive growth responses to -0.3 MPa soil, but different capacities to maintain high root tip water potential corresponding with different growth responses at lower soil water potentials. Both genotypes maintained relatively high nodal root tip water potentials in -2.0 MPa soil, despite the decreased soil water potential, suggesting a stress-induced response that enhances water transport to the root tip. The difference in high tissue water potential maintenance was seen not only between the contrasting genotypes but also between the first two developmental nodes of roots. The divided-chamber system provides a powerful experimental approach to investigate the physiological mechanisms regulating nodal root growth responses to adverse soil conditions. Future studies may include measurements of hydraulic conductivity, anatomical characterization of vascular elements near the growth zone, aquaporin content and activity, and suberin deposition in response to low soil water potentials.

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NITROGEN TRANSFORMATIONS NEAR UREA IN SOIL WITH DIFFERENT WATER POTENTIALS

Canadian Journal of Soil Science ◽

10.4141/cjss88-055 ◽

1988 ◽

Vol 68 (3) ◽

pp. 569-576 ◽

Cited By ~ 14

Author(s):

YADVINDER SINGH ◽

E. G. BEAUCHAMP

Keyword(s):

Water Potential ◽

Soil Water ◽

Incubation Period ◽

Relative Rate ◽

Soil Water Potential ◽

Nitrification Inhibitor ◽

Silt Loam ◽

Nitrogen Transformations ◽

Water Potentials ◽

Initial Soil

Two laboratory incubation experiments were conducted to determine the effect of initial soil water potential on the transformation of urea in large granules to nitrite and nitrate. In the first experiment two soils varying in initial soil water potentials (− 70 and − 140 kPa) were incubated with 2 g urea granules with and without a nitrification inhibitor (dicyandiamide) at 15 °C for 35 d. Only a trace of [Formula: see text] accumulated in a Brookston clay (pH 6.0) during the transformation of urea in 2 g granules. Accumulation of [Formula: see text] was also small (4–6 μg N g−1) in Conestogo silt loam (pH 7.6). Incorporation of dicyandiamide (DCD) into the urea granule at 50 g kg−1 urea significantly reduced the accumulation of [Formula: see text] in this soil. The relative rate of nitrification in the absence of DCD at −140 kPa water potential was 63.5% of that at −70 kPa (average of two soils). DCD reduced the nitrification of urea in 2 g granules by 85% during the 35-d period. In the second experiment a uniform layer of 2 g urea was placed in the center of 20-cm-long cores of Conestogo silt loam with three initial water potentials (−35, −60 and −120 kPa) and the soil was incubated at 15 °C for 45 d. The rate of urea hydrolysis was lowest at −120 kPa and greatest at −35 kPa. Soil pH in the vicinity of the urea layer increased from 7.6 to 9.1 and [Formula: see text] concentration was greater than 3000 μg g−1 soil. There were no significant differences in pH or [Formula: see text] concentration with the three soil water potential treatments at the 10th day of the incubation period. But, in the latter part of the incubation period, pH and [Formula: see text] concentration decreased with increasing soil water potential due to a higher rate of nitrification. Diffusion of various N species including [Formula: see text] was probably greater with the highest water potential treatment. Only small quantities of [Formula: see text] accumulated during nitrification of urea – N. Nitrification of urea increased with increasing water potential. After 35 d of incubation, 19.3, 15.4 and 8.9% of the applied urea had apparently nitrified at −35, −60 and −120 kPa, respectively. Nitrifier activity was completely inhibited in the 0- to 2-cm zone near the urea layer for 35 days. Nitrifier activity increased from an initial level of 8.5 to 73 μg [Formula: see text] in the 3- to 7-cm zone over the 35-d period. Nitrifier activity also increased with increasing soil water potential. Key words: Urea transformation, nitrification, water potential, large granules, nitrifier activity, [Formula: see text] production

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ANÁLISE DE CRESCIMENTO EM CLONES DE EUCALIPTO SUBMETIDOS A ESTRESSE HÍDRICO

Irriga ◽

10.15809/irriga.2010v15n1p98 ◽

2010 ◽

Vol 15 (1) ◽

pp. 98-110 ◽

Cited By ~ 2

Author(s):

Maria Renata Rocha Pereira ◽

Guilherme Sasso Ferreira Souza ◽

Andreia Cristina Peres Rodrigues ◽

Andre Luiz Melhorança Filho ◽

Antonio Evaldo Klar

Keyword(s):

Soil Water ◽

Leaf Area ◽

Genetic Material ◽

Area Index ◽

Growth Ratio ◽

Relative Growth ◽

Water Potentials ◽

Absolute Growth ◽

Hydric Stress ◽

East West

O estudo objetivou avaliar o desempenho de genótipos de plantas de Eucalyptus urograndis (clone 105 e 433) em relação à tolerância à seca, considerando a análise de crescimento das plantas. Para tanto, plantas foram cultivadas em vasos de 8 litros em casa de vegetação. O delineamento foi em inteiramente casualizado, com quatro tratamentos contendo desesseis repetições. O manejo hídrico foi estabelecido com base em dois potenciais mínimos de água (Ψ): -0,03 e -1,5 MPa, através da pesagem diária dos vasos. O desenvolvimento das plantas foi avaliado em coletas a intervalos de 15 dias, iniciando no momento de plantio da muda no vaso até os 60 dias após plantio. Considerando-se o acúmulo de matéria seca total (MS) e o índice de área foliar da planta (IAF) como base para a determinação dos seguintes índices fisiológicos: razão de área foliar (RAF), taxa assimilatória líquida (TAL), área foliar específica (AFE), taxa de crescimento relativo (TCR) e taxa de crescimento absoluto (TCA). Nas condições do experimento, o clone 105 apresentou menor sensibilidade ao déficit hídrico, o que o qualifica como material genético promissor para ambientes sujeitos a estiagem prolongada. Já em condições em que não há restrição hídrica, os dois clones tiveram comportamento semelhantes. UNITERMOS: Eucaliptus urograndis, índices fisiológicos, potenciais hídricos do solo PEREIRA, M. R. R.; SOUZA, G. S. F. de; RODRIGUES, A. C. P.; MELHORANÇA FILHO, A. L.; KLAR, A. E. GROWTH ANALYSIS OF CLONE EUCALIPTUS UNDER HYDRIC STRESS 2 ABSTRACT The aim of this study was to evaluate Eucaliptus grandis genotypes (Clones 105 and 433) in relation to drought tolerance, through growth plant analysis. Black PVC pots with 10 liter volume were used for cultivate plants in polyethilene greenhouse oriented east/west. Completely randonmized design with four treatments was used: two clones and two minimum soil water potentials ( - 0.03 and -1,5 MPa) and sixteen replicates. Pots were weighed daily in order to evaluate water content and characteristic soli water curve was determined. Plant development was obtained each 15 days from planting until 60 days through total dry matter (DM), leaf area index (LAI), leaf area ratio (LAR), net assimilative ratio (NAR), specific leaf area (SLA), relative growth ratio (RGR) and absolute growth ratio (AGR). Results showed that clone 105 presented less sensibility to water deficit, which qualify it as genetic material for use under dry soil conditons. On the other hand, both clones had similar behavior with no water restrictions. KEYWORDS: Eucaliptus grandis, soil water potentials, morphologic measurements.

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The effect of barley yellow dwarf virus on early plant growth in ryegrass (Lolium spp.)

Australian Journal of Agricultural Research ◽

10.1071/ar9890293 ◽

1989 ◽

Vol 40 (2) ◽

pp. 293 ◽

Cited By ~ 6

Author(s):

DR Eagling ◽

RJ Sward ◽

GM Halloran

Keyword(s):

Leaf Area ◽

Growth Rates ◽

Barley Yellow Dwarf Virus ◽

Dry Weight ◽

Relative Growth ◽

Relative Growth Rates ◽

Root Dry Weight ◽

Shoot Dry Weight ◽

Barley Yellow Dwarf ◽

Yellow Dwarf Virus

Measurements were made on the effect of barley yellow dwarf virus (BYDV) infection on the early growth of four commercial cultivars of ryegrass (Lolium spp.) under two different temperatures (24�C and 16�C). At 24'C, BYDV infection was associated with reduced root dry weight (30-40%) in all cultivars; the effect of infection on shoot dry weight and leaf area was variable. At 16�C, the effect of BYDV infection was variable, being associated with increases in root dry weight, shoot dry weight, and leaf area in one cultivar (Grasslands Ariki) and decreases in another (Victorian). In two other cultivars, root dry weight, shoot dry weight and leaf area were not significantly affected (P>0.05) by infection with BYDV.At 24�C, the reductions in root dry weight associated with BYDV infection were not concomitant with reductions in the root relative growth rates. Up to at least 28 days after inoculation (46-50 days after germination) reductions in root dry weight were associated with both aphid-feeding damage and virus infection. Experiments with the cultivar Victorian, showed that shoot dry weight was not significantly affected (P>0.05) by feeding with viruliferous (BYDV) or non-viruliferous aphids (Rhopalosiphum padi L.). At 16�C, changes in root and shoot dry weight were associated with changes in the root and shoot relative growth rates.

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A Comparison of the Respiratory Processes and Growth Rate of Selected Australian Alpine and Related Lowland Plant Species

Functional Plant Biology ◽

10.1071/pp9900517 ◽

1990 ◽

Vol 17 (5) ◽

pp. 517 ◽

Cited By ~ 27

Author(s):

OK Atkin ◽

DA Day

Keyword(s):

Growth Rates ◽

Alternative Oxidase ◽

Geographical Origin ◽

Relative Growth ◽

Relative Growth Rates ◽

Alternative Pathways ◽

Respiration Rates ◽

Whole Plant ◽

Two Temperatures ◽

Plant Respiration

Respiratory processes and growth rates of alpine and lowland species of three genera (Ranunculus, Plantago and Luzula) were compared. Relative growth rates were determined for the first 14 weeks of growth at two temperatures (7-10°C and 12-15°C). Generally, the relative growth rates of the alpine species were lower than those of their lowland relatives. Whole-plant respiration rates were measured and leaf slices from each species were used for a detailed analysis of respiratory pathways. Major differences were found between genera, particularly in their alternative oxidase activity, but respiratory patterns (both whole-plant respiration rates and the relative rates of cytochrome and alternative pathways in leaf slices) were maintained within a given genus, independent of the environmental or geographical origin of each species from that genus. The lack of correlation between growth rates and respiration rates suggests that the alpine plants used their respiratory products less efficiently than did the lowland species.

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Root Growth, Water Uptake and Canopy Development in Eucalyptus viminalis Seedlings

Functional Plant Biology ◽

10.1071/pp9940069 ◽

1994 ◽

Vol 21 (1) ◽

pp. 69 ◽

Cited By ~ 7

Author(s):

JG Phillips ◽

SJ Riha

Keyword(s):

Root Growth ◽

Water Potential ◽

Soil Water ◽

Water Loss ◽

Soil Water Potential ◽

Water Extraction ◽

Soil Conditions ◽

Lower Section ◽

Canopy Development ◽

Eucalyptus Viminalis

A split-root experiment was conducted using Eucalyptus viminalis seedlings which were exposed to three watering regimes in order to investigate root growth and soil water extraction under conditions of a drying soil profile. Seedlings were grown in columns in which the soil was divided horizontally with a soft wax plate. Watering treatments were composed of (1) both upper and lower sections of the column well watered (W/W), (2) only the lower section well watered (D/W), and (3) water withheld completely from both upper and lower sections (D/D). Daily measurements included soil water potential (Ψs), column water loss and leaf elongation. Increase in above- and below-ground biomass was deter- mined from initial and final harvests after 25 days of treatment. Whole-column water loss and leaf extension were depressed as Ψs in the upper section of D/W and D/D decreased to -0.4 MPa over the first 8-10 days. However, water loss did not decrease significantly in the lower section of treatment D/W relative to the lower section of treatment W/W during this period. This indicated that water extraction by roots remaining in wet soil was not severely inhibited by the decrease in transpiration associated with the soil conditions in the upper profile. Root distribution at the end of the experiment indicated significant growth in the lower section of treatment D/W. There was evidence that hydraulic lifting of water between column sections may have occurred, as periodic increases in soil water potential of the unwatered upper section of D/W were observed.

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689 PB 239 SOIL WATER POTENTIAL IRRIGATION CRITERIA FOR ONION PRODUCTION

HortScience ◽

10.21273/hortsci.29.5.531e ◽

1994 ◽

Vol 29 (5) ◽

pp. 531e-531

Author(s):

Erik B. G. Feibert ◽

Clint C. Shock ◽

Monty Saunders

Keyword(s):

Water Potential ◽

Soil Water ◽

Soil Water Potential ◽

Furrow Irrigation ◽

Silt Loam ◽

Yield And Quality ◽

Water Potentials ◽

Granular Matrix ◽

Irrigation Treatments

Onions were grown with different soil water potentials as irrigation criteria to determine the soil water potential at which optimum onion yield and quality occurs. Furrow irrigation treatments in 1992 and 1993 consisted of six soil water potential thresholds (-12.5 to -100 kPa). Soil water potential in the first foot of soil was measured by granular matrix sensors (Watermark Model 200SS, Irrometer Co., Riverside, CA) that had been previously calibrated to tensiometers on the same silt loam series. Both years, yield and market grade based on bulb size (more jumbo and colossal onions) increased with wetter treatments. In 1993, a relatively cool year, onion grade peaked at -37.5 kPa due to a significant increase in rot during storage following the wetter treatments. These results suggest the importance of using moisture criteria to schedule irrigations for onions.

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Comparing natural and planted black spruce seedlings. I. Water relations and growth

Canadian Journal of Forest Research ◽

10.1139/x93-300 ◽

1993 ◽

Vol 23 (11) ◽

pp. 2427-2434 ◽

Cited By ~ 15

Author(s):

Pierre Y. Bernier

Keyword(s):

Water Potential ◽

Growth Rates ◽

Water Movement ◽

Black Spruce ◽

Water Status ◽

Site Conditions ◽

Relative Growth ◽

Relative Growth Rates ◽

Growing Seasons ◽

The Difference

Container-grown black spruce (Piceamariana (Mill.) B.S.P.) seedlings were planted during 2 consecutive years alongside natural black spruce seedlings of similar initial height on an upland boreal forest clearcut. Acclimation of the planted seedlings to site conditions was followed by comparing needle conductance, shoot water potential, and growth of the planted seedlings to values obtained on the natural seedlings. Relative growth rates of the newly planted seedlings were significantly lower than those of the natural seedlings, but the difference was smaller during their second season in the field. Predawn and midday shoot water potential as well as midday needle conductance showed significant but relatively small differences between planted and natural seedlings during both years. On any given date of measurement, no clear relation could be found between water status and growth in planted seedlings. Seasonal midday averages of shoot water potential, needle conductance, and soil–plant resistance to water movement were related to the relative growth rates of all seedling types over the course of the two growing seasons. Seasonal averages of midday shoot water potential appeared to best reflect the acclimation of the planted seedlings to site conditions.

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