Effects of soil temperature on the carbon exchange of taiga seedlings.: I. Root respiration

1983 ◽  
Vol 13 (5) ◽  
pp. 840-849 ◽  
Author(s):  
William T. Lawrence ◽  
Walter C. Oechel
Keyword(s):  
Soil Temperature ◽  
Root Respiration ◽  
Dry Weight ◽  
Soil Mass ◽  
Day Length ◽  
Maintenance Respiration ◽  
Root Dry Weight ◽  
Soil Temperatures ◽  
Growth Respiration ◽  
Species Specific

Seedlings of Alnuscrispa (Ait.) Pursh, Populusbalsamifera L., Populustremuloides Michx., and Betulapapyrifera Marsh., hardwood species of the taiga of interior Alaska, were grown in sand in a controlled environment room at day–night temperatures of 25 and 20 °C, respectively, with a 20-h day length. After establishment, pots containing each species were placed under soil-temperature treatments of 5, 15, and 25 °C while maintaining extant air-temperature and light regimes. Both total and maintenance respiration of the roots were measured under these temperature treatments by monitoring the efflux of CO2 from the potted soil mass. An estimate of root-growth respiration was calculated as the difference between total and maintenance respiration. Total root respiration increased from three- to five-fold as soil temperature increased over the 20 °C experimental range. Growth-respiration response was species specific, occurring only at 5 °C soil temperature in A. crispa, at both 15 and 25 °C in P. balsamifera, and at all three soil temperatures in P. tremuloides. Growth respiration of the roots was a nearly constant fraction of total root respiration within a species, averaging 0.17 mg CO2•h−1•g root dry weight−1 in A. crispa and P. balsamifera, but nearly twice that, 0.33 mg CO2•h−1•g root dry weight−1, in P. tremuloides. Growth respiration was not determined for B. papyrifera.

Effect of soil temperature, seeding depth and cultivar on wheat tolerance to simulated ethalfluralin carryover

1997 ◽  
Vol 77 (1) ◽  
pp. 181-188
Author(s):  
A. L. Darwent ◽  
L. P. Lefkovitch ◽  
P. F. Mills
Keyword(s):  
Soil Temperature ◽  
Plant Density ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Minor Effect ◽  
Cultivar Selection ◽  
Soil Temperatures ◽  
Environment Experiment ◽  
A Minor

Field and controlled environment experiments were conducted at Beaverlodge, Alberta to determine the effect of soil temperature, seeding depth and cultivar on wheat (Triticum aestivum L.) tolerance to ethalfluralin. In one experiment, ethalfluralin was applied and incorporated, and wheat was seeded at several depths in late April/early May when soil temperatures were lowest or in late May when soil temperatures had increased. Mean 3-yr wheat yields decreased by 45% as the rate of ethalfluralin increased from 0 to 0.75 kg ha−1 and by 21% as the depth of seeding increased from 4 to 12.5 cm but the effect of ethalfluralin on yields was similar regardless of the soil temperature (time of seeding). Mean plant density decreased by 55% as the rate of ethalfluralin increased and by 25% as the depth of seeding increased. Reductions in mean plant density from ethalfluralin were slightly greater when seeded into the warmer soils. In another experiment, the effect of ethalfluralin on the yields of three wheat cultivars, Laura, Conway and Biggar was similar, i.e. the cultivar × rate of ethalfluralin interaction was not significant. However, the mean plant density of Biggar, averaged over rates of ethalfluralin, was less than that of the other cultivars in 1 of 2 yr. In a controlled environment experiment, the oven-dry weight and percent emergence of wheat shoots of the cultivars, Katepwa, Laura and Conway, seeded at 1.5 or 4 cm into soils containing ethalfluralin at concentrations of 0 to 4 ppm and maintained at temperatures of 4.5 or 15 °C, were reduced by decreases in temperature and increases in the rate of herbicide and depth of seeding. However, the interaction of soil temperature × rate of ethalfluralin was not significant for the oven-dry weight of the wheat shoots and the reduction in percent emergence of the wheat shoots as the rate of ethalfluralin increased was only slightly greater at 4.5 °C than at 15 °C. These results indicate that soil temperature and cultivar selection have a minor effect on wheat tolerance to ethalfluralin while herbicide concentration and depth of seeding have a major impact. Key words: Ethalfluralin, wheat, seeding depth, soil temperature, cultivar

scholarly journals Light Effects on Wax Begonia: Photosynthesis, Growth Respiration, Maintenance Respiration, and Carbon Use Efficiency

2004 ◽  
Vol 129 (3) ◽  
pp. 416-424 ◽  
Author(s):  
Krishna S. Nemali ◽  
M.W. van Iersel
Keyword(s):  
Growth Period ◽  
Dry Weight ◽  
Carbon Gain ◽  
Maintenance Respiration ◽  
Gross Photosynthesis ◽  
Carbon Use Efficiency ◽  
Whole Plant ◽  
Growth Respiration ◽  
Use Efficiency ◽  
Gas Exchange System

The effect of increasing daily light integral (DLI; 5.3, 9.5, 14.4, and 19.4 mol·m-2·d-1) on photosynthesis and respiration of wax begonia (Begonia semperflorens-cultorum Hort.) was examined by measuring CO2 exchange rates (CER) for a period of 25 d in a whole-plant gas exchange system. Although plant growth rate (GR, increase in dry weight per day) increased linearly with increasing DLI, plants grown at low DLI (5.3 or 9.5 mol·m-2·d-1) respired more carbohydrates than were fixed in photosynthesis during the early growth period (13 and 4 d, respectively), resulting in a negative daily carbon gain (DCG) and GR. Carbon use efficiency [CUE, the ratio of carbon incorporated into the plant to C fixed in gross photosynthesis (Pg)] of plants grown at low DLI was low, since these plants used most of the C fixed in Pg for maintenance respiration (Rm), leaving few, if any, C for growth and growth respiration (Rg). Maintenance respiration accounted for a smaller fraction of the total respiration with increasing DLI. In addition, the importance of Rm in the carbon balance of the plants decreased over time, resulting in an increase in CUE. At harvest, crop dry weight (DWCROP) increased linearly with increasing DLI, due to the increased photosynthesis and CUE at high PPF.

EFFETS DES TEMPERATURES DU SOL, DES DATES DE SEMIS ET DES MAUVAISES HERBES SUR LES COMPOSANTES DU RENDEMENT DE L’AVOINE

1980 ◽  
Vol 60 (1) ◽  
pp. 61-68 ◽  
Author(s):  
J. M. DESCHENES ◽  
C. A. ST-PIERRE
Keyword(s):  
Soil Temperature ◽  
Grain Yield ◽  
Field Experiments ◽  
Sandy Loam ◽  
Dry Weight ◽  
Soil Types ◽  
Grain Yields ◽  
Soil Temperatures ◽  
Weed Infestation ◽  
Hand Weeding

On a St-André sandy loam and on a Kamouraska clay, the effect of soil temperature on oats (Avena sativa L.) was measured in the greenhouse using a system described by Deschênes et al. in 1974 and in the field, using two dates of seeding. The effect of weeds was measured by using un weeded and hand-weeded treatments. In the greenhouse, cool soil temperatures have delayed maturity and decreased straw and grain yields as well as total phytomass of oats on the two soil types. The dry weight of weeds in un weeded pots increased slightly. The effect of hand-weeding on oats was especially noticeable on the St-André sandy loam where three times as many weeds were observed. The straw yield and the total phytomass of oats were higher in the field experiment following an early seeding of oats on both soil types. On the other hand, grain yield was lower on plots seeded early and located on St-André sandy loam while the opposite was true on Kamouraska clay. The dry weight of weeds was lower on unweeded plots seeded early. The weeds reduced straw and grain yields on the St-André sandy loam but had no effect on Kamouraska clay because of the low weed infestation on the latter. The greenhouse and field experiments suggest that soil temperature is not the main factor in explaining the increase in grain yield observed with early-seeded cereals.

Predicting fine root production and turnover by monitoring root starch and soil temperature

1985 ◽  
Vol 15 (5) ◽  
pp. 791-800 ◽  
Author(s):  
J. D. Marshall ◽  
R. H. Waring
Keyword(s):  
Soil Temperature ◽  
Carbon Balance ◽  
Fine Root ◽  
Dry Weight ◽  
Root Production ◽  
Maintenance Respiration ◽  
Root Carbon ◽  
Respiration Rates ◽  
Root Starch ◽  
Maintenance Requirements

To determine how the longevity of fine roots (those without secondary thickening) is controlled, shoots of Douglas-fir (Pseudotsugamenziesii Mirb. (Franco)) seedlings were exposed to light or maintained in darkness while roots were maintained at 10, 20, or 30 °C. Fine root maintenance respiration rates, estimated from rates of starch and sugar depletion in the seedlings maintained in darkness, ranged from 0.83 to 3.25 mg starch g dry weight−1 day−1. At 20 and 30 °C, starch deposition was curtailed and previously deposited starch was used to maintain the older roots, whether current photosynthate was entering the root system or not. On the other hand, at 10 °C starch was deposited in the roots whenever the root systems grew. Based on these results, we suggest that starch deposition in a fine root occurs only when the root is being formed and the root carbon balance is positive. Starch is subsequently respired to meet maintenance requirements exclusively. A simple means of estimating root biomass production and turnover based on root starch and soil temperature is described and compared with field estimates.

Effect of Root Temperature on Growth and Seed Yield in Cowpea (Vigna Unguiculata)

1976 ◽  
Vol 12 (3) ◽  
pp. 279-288 ◽  
Author(s):  
F.R. Minchin ◽  
P.A. Huxley ◽  
R.J. Summerfield
Keyword(s):  
Soil Temperature ◽  
Seed Yield ◽  
Vegetative Growth ◽  
Dry Weight ◽  
Leaf Production ◽  
Cowpea Cultivars ◽  
Temperature Regimes ◽  
Soil Temperatures ◽  
The Uk ◽  
Seed Yields

The effects of different soil temperature regimes on vegetative growth, symbiotic nitrogen fixation and seed yield of two cowpea cultivars (K 2809 and Prima) were investigated in experiments carried out in plastic houses during the UK summer. Mean maximum soil temperatures above 32°C significantly reduced vegetative growth of both cultivars, through their effects on branch, peduncle and root dry weight per plant and, to a lesser extent, leaf production. The warmest temperature regime (35.4°C) also reduced nodule activity, especially in cv. Prima. Seed yields were adversely affected, due largely to changes in the number of peduncles per plant, as mean maximum soil temperature increased from 25.8 to 35.4°C.

Influence of soil temperature on the development of pea root rot

1969 ◽  
Vol 47 (4) ◽  
pp. 567-574 ◽  
Author(s):  
W. G. Benedict
Keyword(s):  
Soil Temperature ◽  
Root Rot ◽  
Seed Weight ◽  
Day Length ◽  
Control Soil ◽  
Fusarium Spp ◽  
Plant Weight ◽  
Wide Range ◽  
Soil Temperatures ◽  
Pea Root Rot

Pisum sativum vars. Early June, Early Sweet, and Sweet were grown in five root-rot soils and a sterilized control soil maintained at 28°, 26°, 24°, 22°, 18°, 16°, 14°, and 10 °C. Light intensity, day length, and soil moisture were kept constant. Data were recorded from seeding to mature plant development on loss of seed weight, gain in plant weight and height, losses due to preemergence killing and postemergence wilting, lesioning on the subterranean part of the epicotyls, and the fungi and nematodes found associated with the diseased tissues. Results showed that soil temperature generally, with distinct exceptions, had a definite influence on the growth of the peas, according to varieties, in the root rot soils. One fungus predominated as the causal agent of root rot for each variety: Fusarium spp. for var. Early June, which was highly tolerant to root rot soil, and Rhizoctonia solani for Early Sweet and Sweet, which were later maturing varieties. Pythium spp. was also involved in the root rot. The number of seedlings lost as a result of preemergence killing showed greater variation in relation to pea variety and root-rot soil than soil temperature, but postemergence wilting was correlated more closely with soil temperature. The variety Early Sweet was so susceptible to root rot over a wide range of soil temperatures as to preclude its general use in pea-growing areas.

scholarly journals 593 Water Stress Influences Soil/Root Respiration Rate and Root Morphology of Young Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 549B-549
Author(s):  
Georgios Psarras ◽  
Ian A. Merwin
Keyword(s):  
Water Stress ◽  
Root Morphology ◽  
Root Respiration ◽  
Dry Weight ◽  
Root Systems ◽  
Respiration Rates ◽  
Electric Capacitance ◽  
Root Dry Weight ◽  
Root Size ◽  
Root Capacitance

One-year-old potted `Mutsu' apple (Malus domestica) trees on MM.111 and M.9 rootstocks were grown outdoors from May to Nov. 1997, under three levels of soil-water availability (–20, –80, and –200 kPa), to evaluate the effects of water stress on soil/root respiration and root morphology. At weekly intervals, we measured soil/root respiration using a portable infrared gas analyzer and rootsystem size or functional activity using an electric capacitance meter. These observations were tested as nondestructive methods to estimate relative differences in root size and morphology in situ compared with final dry weight and form of excavated apple rootstocks. Root size-class distributions were estimated by digital imaging and analysis of harvested root systems. Root growth was substantially reduced by water stress; the magnitude of reduction was similar for both rootstocks, but the percentage of shoot growth reduction was higher for MM.111. Root: shoot ratios were higher and average specific respiration rates over the growing season were lower for M.9 root systems. Water stress increased the root: shoot ratio, specific root length, and carbon costs of root maintenance as indicated by specific respiration rates. Soil/root respiration was more closely correlated than root electric capacitance with actual root system size. The observed r2 values between root capacitance and root dry weight were as high as 0.73, but root capacitance was also confounded by other factors, limiting its usefulness for nondestructive estimation of root size or activity. Rootstock genotype significantly affected root capacitance, which provided better estimates of root dry weight for M.9 than for MM.111.

scholarly journals Photoperiod of Poinsettia Stock Plants Influences Adventitious Rooting of Cuttings

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 567a-567
Author(s):  
Michael J. Roll ◽  
Steven E. Newman
Keyword(s):  
Dry Weight ◽  
Adventitious Rooting ◽  
Day Length ◽  
Root Weight ◽  
Flower Initiation ◽  
Stock Plant ◽  
Root Dry Weight ◽  
Plant Stage ◽  
Rooting Of Cuttings

The rooting efficiency of cuttings from three poinsettia cultivars were evaluated after regulating the photoperiod during the stock plant stage. `Freedom Red', `Monet', and `V-17 Angelika Marble' stock plants were exposed to an extended photoperiod and to natural day length during September 1995. `Freedom Red' cuttings rooted more quickly under an extended photoperiod compared to those under natural day length. Furthermore, root dry weight from these cuttings was greater than cuttings from stock plants grown under natural day length. `Monet' cuttings also rooted more quickly when the stock plants were under an extended photoperiod, and showed similar differences in root weight as `Freedom Red'. Cuttings from `V-17 Angelika Marble' were not influenced by photoperiod. Lighting stock plants to block flower initiation produces a higher quality cutting when propagation takes place after the critical day length for flowering has passed.

scholarly journals Soil Temperature and Precipitation Affect the Rooting Ability of Dormant Hardwood Cuttings of Populus

2005 ◽  
Vol 54 (1-6) ◽  
pp. 47-58 ◽  
Author(s):  
R. S. Zalesny ◽  
R. B. Hall ◽  
E. O. Bauer ◽  
D. E. Riemenschneider
Keyword(s):  
Soil Temperature ◽  
Root Length ◽  
Dry Weight ◽  
Precipitation Event ◽  
Base Temperature ◽  
Planting Dates ◽  
Growing Period ◽  
Rooting Ability ◽  
Temperature And Precipitation ◽  
Soil Temperatures

Abstract In addition to genetic control, responses to environmental stimuli affect the success of rooting. Our objectives were to: 1) assess the variation in rooting ability among 21 Populus clones grown under varying soil temperatures and amounts of precipitation and 2) identify combinations of soil temperature and precipitation that promote rooting. The clones belonged to five genomic groups ([P. trichocarpa Torr. & Gray x P. deltoides Bartr. ex Marsh] x P. deltoides ‘BC’; P. deltoides ‘D’; P. deltoides x P. maximowiczii A. Henry ‘DM’; P. deltoides x P. nigra L. ‘DN’; P. nigra x P. maximowiczii ‘NM’). Cuttings, 20 cm long, were planted in Iowa and Minnesota, USA, in randomized complete blocks at 1.2- x 2.4-m spacing across three planting dates during 2001 and 2002. Soil temperatures were converted to belowground growing degree days (GDD) (base temperature = 10°C) accumulated over 14 days. Genomic groups responded similarly for root dry weight, number of roots, total root length, and mean root length, that increased as belowground GDD increased. Belowground GDD and precipitation governed rooting throughout the 14-d growing period. A minimum of four days above 14°C, along with sufficiently dispersed precipitation (e.g. no more than 3 d without a precipitation event), were needed to sustain aboveaverage rooting. Therefore, we recommend using a base temperature of 14°C for future models estimating belowground GDD in northern temperate zones.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

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