Factors affecting transfer and spread of Phellinusweirii mycelium in roots of second-growth Douglas-fir

1982 ◽  
Vol 12 (2) ◽  
pp. 424-427 ◽  
Author(s):  
W. J. Bloomberg ◽  
G. Reynolds
Keyword(s):  
Relative Position ◽  
Soil Depth ◽  
Root Surface ◽  
Contact Length ◽  
Root Diameter ◽  
Douglas Fir ◽  
Factors Affecting ◽  
Second Growth ◽  
Root Collar ◽  
Successful Transfer

Effects of site, root diameter, soil depth of interroot contact, length of root surface in contact, type of contact, and relative position of roots were investigated on the frequency of transfer of Phellinusweirii (Murr.) Gilbertson mycelium between roots and its spread along roots of second-growth Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). Successful transfer of P. weirii as ectotrophic or endotrophic mycelium occurred in 32 and 3%, respectively, of total number of interroot contacts. Unsuccessful transfers occurred in 4 and 62%, respectively, with the balance of contacts having undetermined transfers, owing to extension of mycelium to the root collar of both roots in contact. A Pseudotsuga–Polystichum site had a higher frequency of unsuccessful transfer than two Pseudotsuga–Gaultheria sites. Average root diameter was greater and average depth was less in contacts with successful transfers than in those with unsuccessful transfers. Type or length of contact or relative position of roots had no significant effects on transfers. There was a highly significant inverse relationship between root diameter and length of endotrophic mycelial spread as measured by decay column. The regression of endotrophic on ectotrophic mycelial spread along roots was highly significant for both proximal and distal spread. In most roots, ectotrophic mycelium had spread distally to the tip and proximally to the stump, whereas endotrophic mycelium had not.

Fungal deterioration of second-growth Douglas-fir logs in coastal British Columbia

1970 ◽  
Vol 48 (9) ◽  
pp. 1541-1551 ◽  
Author(s):  
R. B. Smith ◽  
H. M. Craig ◽  
D. Chu
Keyword(s):  
Seasonal Pattern ◽  
Wood Decay ◽  
Late Summer ◽  
Douglas Fir ◽  
White Rot ◽  
Decay Fungi ◽  
Deterioration Rate ◽  
Second Growth ◽  
Autumn And Winter ◽  
Fungal Deterioration

Fungal deterioration of second-growth Douglas-fir logs, felled each month from August 1961 to May 1962, was studied 2, 4, and 6 years after felling. Decay increased from 10% of log volumes after 2 years to 47% after 6 years. The rate of decay, particularly for the brown cubical type, was greater for autumn- and winter-felled logs than for those felled in the spring and late summer, and closely paralleled the seasonal pattern of ambrosia beetle attack.Decay rates increased with decreasing log size, increasing percentage of sapwood, and increasing height of log above ground. For the same diameter of log, base logs decayed less rapidly than second logs, possibly because of their lower proportion of sapwood in relation to heartwood.Decay expressed as a percentage of total log volume (Y) may be estimated (R2 = 0.71) with the following equation: Y = 13.2 + 10.7X1 − 3.2X2, where X1 = years elapsed and X2 = d.i.b. (diameter inside bark) top of log.Of 30 wood-decay fungi isolated, Naematoloma sp. (N. capnoides or N. fasciculare), which causes a white rot, was associated with the most decay. Fomes pinicola was mainly responsible for brown cubical sap rot, while Poria monticola and P. carbonica caused a brown cubical heart rot at the ends of logs.The significance of variations in deterioration rate and fungal associates is discussed in relation to log durability and salvability.

Structural Properties of Second-Growth Douglas-Fir Logging Spars

1987 ◽  
Vol 30 (1) ◽  
pp. 0065-0069 ◽  
Author(s):  
Marvin R. Pyles
Keyword(s):  
Structural Properties ◽  
Douglas Fir ◽  
Second Growth

scholarly journals Effect of Aqueous Neem Leaf Extracts in Controlling Fusarium Wilt, Soil Physicochemical Properties and Growth Performance of Banana (Musa spp.)

2021 ◽  
Vol 13 (22) ◽  
pp. 12335
Author(s):  
Ung Yi ◽  
Sakimin Siti Zaharah ◽  
Siti Izera Ismail ◽  
Mohamed Hanafi Musa
Keyword(s):  
Physicochemical Properties ◽  
Growth Performance ◽  
Fusarium Wilt ◽  
Root Surface ◽  
Root Diameter ◽  
Plant Diseases ◽  
Root Surface Area ◽  
Soil Physicochemical Properties ◽  
Leaf Extracts ◽  
Root Shoot Ratio

Neem leaf extracts (NLEs) have frequently been used to inhibit plant diseases and for the development of bio-fertilizer, leading to the commercial exploitation of this tree. However, previous studies have indicated contradictory outcomes when NLE was used as an antifungal disease treatment and bio-fertilizer applied through the soil on several crops, including banana. Therefore, the present investigation was undertaken to examine the physicochemical properties of soil, the growth performance of crops, and the severity of diseases caused by Fusarium oxysporum (Foc) on Cavendish bananas treated with aqueous NLE. Banana plants associated with the fungus were significantly affected by high disease severity and symptoms index (external leaves and internal rhizome), a high infection percentage of Fusarium wilt (%), dropping off of leaves as well as rotting of the root. Meanwhile, it was observed that the application of extract significantly improved the crop height, stem diameter, root size and distribution (root surface area, root diameter, and root volume), root–shoot ratio, as well as the soil physicochemical properties (CEC, N, p, K, Ca, and Mg), which enhanced resistance to Fusarium wilt diseases. We conclude that the application of NLE solution promotes better growth of Cavendish banana plants, soil physicochemical properties, and resistance to Fusarium wilt infection.

scholarly journals Profiles of C- and N-trace gas production in N-saturated forest soils

2005 ◽  
Vol 2 (4) ◽  
pp. 1127-1157 ◽  
Author(s):  
K. Butterbach-Bahl ◽  
U. Berger ◽  
N. Brüggemann ◽  
J. Duyzer
Keyword(s):  
Forest Soils ◽  
Forest Floor ◽  
Soil Depth ◽  
Douglas Fir ◽  
Anaerobic Incubation ◽  
N2o Production ◽  
Time Activity ◽  
Soil Layers ◽  
Clear Cut ◽  
First Time

Abstract. This study provides for the first time data on the stratification of NO and N2O production with soil depth under aerobic and anaerobic incubation conditions for different temperate forest sites in Germany (spruce, beech, clear-cut) and the Netherlands (Douglas fir). Results show that the NO and N2O production activity is highest in the forest floor and decreases exponentially with increasing soil depth. Under anaerobic incubation conditions NO and N2O production was in all soil layers up to 2-3 orders of magnitude higher then under aerobic incubation conditions. Furthermore, significant differences between sites could be demonstrated with respect to the magnitude or predominance of NO and N2O production. These were driven by stand properties (beech or spruce) or management (clear-cut versus control). With regard to CH4 the most striking result was the lack of CH4 uptake activity in soil samples taken from the Dutch Douglas fir site at Speulderbos, which is most likely a consequence of chronically high rates of atmospheric N deposition. In addition, we could also demonstrate that CH4 fluxes at the soil surface are obviously the result of simultaneously occurring uptake and production processes, since even under aerobic conditions a net production of CH4 in forest floor samples was found. The provided dataset will be very useful for the development and testing of process oriented models, since for the first time activity data stratified for several soil layers for N2O, NO, and CH4 production/oxidation activity for forest soils are provided.

Twenty-year survival of Phellinus (Poria) weirii in Douglas-fir stumps

1976 ◽  
Vol 6 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Everett M. Hansen
Keyword(s):  
Root Systems ◽  
Root Diameter ◽  
Douglas Fir ◽  
Hand Tools ◽  
Outer Limit ◽  
Dying Back

Fungus survival was examined in root systems of stumps of trees that were harvested 20 years previously. Roots were excavated with dynamite and hand tools to the outer limit of living P. weirii or until the roots went deeper than 45 cm. Sixty-nine stumps infected before harvest were excavated; P. weirii was still viable in 94%. The fungus was dying back in 68% of the stumps. Some roots as small as 1.3 cm had viable P. weirii, but the margin between living and dead P. weirii occurred at an average root diameter of 12.5 cm.The margin between living and dead P. weirii was often marked by a black zone line. The fungus survived only within roots with intact bark. Ectotrophic mycelium occurred in discontinuous patches on roots of 33% of the stumps.

scholarly journals Plant Growth Regulator Effects on Germination and Root Traits of ‘Lambada’ and ‘Don Victor’ Onion Cultivars

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1759-1764
Author(s):  
Maria A. Macias-Leon ◽  
Daniel I. Leskovar
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Synergistic Effects ◽  
Field Performance ◽  
Root Traits ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Relative Growth ◽  
Relative Growth Rates

Onions (Allium cepa L.) are easily outcompeted by weeds because of slow germination and relative growth rates. Therefore, high percentage of seed germination and root vigor are important traits to improve field performance. The effects of exogenous plant growth regulators (PGRs), 2-chloroethylphosphonic acid (ethephon, Eth), indole-3-acetic acid (IAA), trans-zeatin (tZ), and 1-aminocyclopropane-1-carboxylic acid (ACC) were evaluated on the germination and root growth of ‘Don Victor’ (yellow) and ‘Lambada’ (red) onion seedlings. Seeds were soaked for 10 hours in hormonal solutions and water (hydro-priming). Seed germination improved with Eth (30 and 100 μm), Eth (100 μm) + IAA (10 μm), and IAA (3 μm) treatments. Root surface area (RSA) increased in response to Eth at 30 and 100 μm, Eth + IAA, and 3 μm IAA. Root length (RL) and root diameter (RD) were enhanced by 1 μm tZ and 100 μm ACC. Eth reduced RL and RD, whereas IAA showed no effects. A subsequent experiment evaluated synergistic effects of different PGRs. Treatment of seeds with ACC (250 μm) + tZ (0.5 μm) and ACC (250 μm) + tZ (0.5 μm) + Eth (20 μm) enhanced RL and RD. RSA was unaffected by ACC + tZ + Eth. The results suggest that exogenous PGRs could be useful to enhance germination, RL, and RSA of onion seedlings.

Load-Carrying Capacity of Second-Growth Douglas-Fir Stump Anchors

1987 ◽  
Vol 2 (3) ◽  
pp. 77-80 ◽  
Author(s):  
Marvin R. Pyles ◽  
Joan Stoupa
Keyword(s):  
Carrying Capacity ◽  
Deformation Behavior ◽  
Ultimate Load ◽  
Douglas Fir ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Tree Diameter ◽  
Second Growth ◽  
Load Carrying ◽  
Load Tests

Abstract In order to quantify the stump anchor capacity of small second-growth Douglas-fir (Pseudotsuga menziesii [Mirb]. Franco) trees, load tests to failure were conducted on 18 stumps from trees 7 to 16.5 in dbh. The tests produced ultimate loads that varied as the square of the tree diameter. However, the ultimate load typically occurred at stump system deformations that were far in excess of that which would be considered failure of a stump anchor. A hyperbolic equation was used to describe the load-deformation behavior of each stump tested and was generalized to describe all the test results. West. J. Appl. For. 2(3):72-80, July 1987.

scholarly journals Comparison of Root System Morphology of Cucurbit Rootstocks for Use in Watermelon Grafting

2018 ◽  
Vol 28 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Matthew B. Bertucci ◽  
David H. Suchoff ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Christopher C. Gunter ◽  
...  
Keyword(s):  
Root System ◽  
Surface Area ◽  
Root Length ◽  
Dry Weight ◽  
Root Systems ◽  
Root Surface ◽  
Root Diameter ◽  
Root Surface Area ◽  
Diameter Class ◽  
Main Effect

Grafting of watermelon (Citrullus lanatus) is an established production practice that provides resistance to soilborne diseases or tolerance to abiotic stresses. Watermelon may be grafted on several cucurbit species (interspecific grafting); however, little research exists to describe root systems of these diverse rootstocks. A greenhouse study was conducted to compare root system morphology of nine commercially available cucurbit rootstocks, representing four species: pumpkin (Cucurbita maxima), squash (Cucurbita pepo), bottle gourd (Lagenaria siceraria), and an interspecific hybrid squash (C. maxima × C. moschata). Rootstocks were grafted with a triploid watermelon scion (‘Exclamation’), and root systems were compared with nongrafted (NG) and self-grafted (SG) ‘Exclamation’. Plants were harvested destructively at 1, 2, and 3 weeks after transplant (WAT), and data were collected on scion dry weight, total root length (TRL), average root diameter, root surface area, root:shoot dry-weight ratio, root diameter class proportions, and specific root length. For all response variables, the main effect of rootstock and rootstock species was significant (P < 0.05). The main effect of harvest was significant (P < 0.05) for all response variables, with the exception of TRL proportion in diameter class 2. ‘Ferro’ rootstock produced the largest TRL and root surface area, with observed values 122% and 120% greater than the smallest root system (‘Exclamation’ SG), respectively. Among rootstock species, pumpkin produced the largest TRL and root surface area, with observed values 100% and 82% greater than those of watermelon, respectively. These results demonstrate that substantial differences exist during the initial 3 WAT in root system morphology of rootstocks and rootstock species available for watermelon grafting and that morphologic differences of root systems can be characterized using image analysis.

FACTORS AFFECTING THE VIABILITY AND GERMINATION BEHAVIOR OF CONIFEROUS SEED. IV. STRATIFICATION PERIOD AND INCUBATION TEMPERATURE, PSEUDOTSUGA MENZESII (MIRB.) FRANCO

1960 ◽  
Vol 36 (1) ◽  
pp. 18-29 ◽  
Author(s):  
G. S. Allen
Keyword(s):  
Incubation Temperature ◽  
Douglas Fir ◽  
Factors Affecting ◽  
Cold Spring ◽  
Geographic Sources

Douglas fir seed from 10 geographic sources was stratified for periods of up to 150 days in length and incubated at 10, 15, 20, 25, and 30 °C. The relatively rapid germination at 10 °C following the longer periods of stratification indicates advantages for nurseries subject to cold spring weather. The observed decrease of germination per cent (and apparent germinative capacity) after long periods of stratification of some lots suggests that long stratification may be used as a test of vigor or durability. Separation of Coastal seed lots from Interior seed lots, and further separation of these into broad classes appears possible on the basis of germination behavior at 10 °C or 15 °C following a specific period of stratification such as 20 or 40 days.

Differential Root Morphology between Metallicolous and Non-Metallicolous Populations of Rumex japonicus under Copper Stress

2013 ◽  
Vol 726-731 ◽  
pp. 81-84
Author(s):  
Wu Xing Huang ◽  
Cong Ren ◽  
Jing Qing Gao
Keyword(s):  
Root Morphology ◽  
Root Surface ◽  
Root Diameter ◽  
Copper Stress ◽  
Shoot Biomass ◽  
Root Surface Area ◽  
Cu Stress ◽  
Root Shoot Ratio ◽  
Rumex Japonicus ◽  
Two Populations

Two Rumex japonicus populations, one from copper (Cu) mine and the other from uncontaminated site, were studied for root morphology and biomass under Cu stress. Main root length and number of tips of the two populations were both significantly inhibited by Cu treatments. However, those of metallicolous population (MP) were higher than non-metallicolous population (NMP) under Cu stress. Cu treatments significantly inhibited root surface area in NMP while MP showed little difference from control. Cu treatments inhibited average root diameter and root/shoot ratio in NMP, but those in MP were significantly higher than control. Cu treatments significantly inhibited shoot biomass and root biomass in NMP. These results suggested that more assimilates allocated to root and the average root diameter increased under Cu stress to form a greater and stronger root might be partly reasons why R. japonicus can colonize the Cu enriched soils.

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