Decomposition of cotton by Trichoderma species: influence of temperature, soil type, and nitrogen levels

1989 ◽  
Vol 35 (4) ◽  
pp. 469-473 ◽  
Author(s):  
Paul Widden ◽  
John Cunningham ◽  
Brenda Breil
Keyword(s):  
Tensile Strength ◽  
Soil Nitrogen ◽  
Soil Chemistry ◽  
Silica Sand ◽  
Effect Of Temperature ◽  
White Pine ◽  
Trichoderma Species ◽  
Cellulose Decomposition ◽  
Nitrogen Levels ◽  
Low Nitrogen

The effect of temperature on the ability of five species of Trichoderma to decompose cellulose was evaluated in three types of sterilized soils. The loss in tensile strength of cotton strips was used as an index of cellulose decomposition. The influence of levels of nitrogen on cotton degradation was also evaluated using silica sand as a substitute for soil. A greater loss in cotton tensile strength was obtained with T. virens and T. viride than with T. hamatum, T. polysporum, or T. koningii. All species responded similarly to nitrogen levels and temperature, with decreased activity at low nitrogen and low temperature. The soil also had a large influence on the rate of decomposition of the strips. The soil from a maple forest gave rise to greater losses in tensile strength than did soil from a white pine or Norway spruce plantation. These results emphasize the importance of the soil chemistry in determining fungal activities in the field, and the difficulties of extrapolating results of cellulose utilization studies in the laboratory to the field.Key words: Trichoderma, cellulolysis, soil, nitrogen, temperature.

Exposure to aphids increases alder growth and nitrogen fixation

Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Corinthe Zekveld ◽  
John Markham
Keyword(s):  
Soil Nitrogen ◽  
Plant Nutrition ◽  
Soil Microbes ◽  
Nitrogen Fixing ◽  
Root:Shoot Ratio ◽  
Herbivore Damage ◽  
Resistance Response ◽  
Nitrogen Levels ◽  
Alnus Viridis ◽  
Low Nitrogen

Plants can respond to herbivore damage by mounting a resistance response or by compensating for lost fitness. Both plant nutrition and interactions with soil microbes can affect these responses. It has been shown that resistance responses can occur before plants have been attacked by herbivores. Here we show that a tolerance type of response can occur when plants are exposed to, but not fed on by, herbivores. Alnus viridis (Chaix) DC. spp. crispa (Ait.) Turrill were grown in sealed containers under positive air pressure with either 0.5 mmol·L–1 or 2.0 mmol·L–1 nitrate and either inoculated or not inoculated with Frankia , their nitrogen-fixing symbiont. Plants were then exposed to the genus-specific aphid Prociphilus tessallatus Fitch, which failed to establish feeding colonies. Exposure to aphids, formation of nitrogen-fixing nodules, and elevated soil nitrogen levels all significantly increased plant yield with no interaction among these factors. A combination of high soil nitrogen, nodulation, and exposure to aphids resulted in the lowest plant root:shoot ratio. Plants that were grown with low nitrogen and were exposed to aphids showed increased nitrogen-fixing activity within a day of being exposed. These results provide further evidence to support the observation that plants can respond to cues from other organisms prior to receiving herbivore damage.

INORGANIC NITROGEN LEVELS AND NITRIFICATION POTENTIAL IN LOWBUSH BLUEBERRY SOILS

1988 ◽  
Vol 68 (1) ◽  
pp. 63-75 ◽  
Author(s):  
LEONARD J. EATON ◽  
DAVID G. PATRIQUIN
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulfate ◽  
Soil Nitrogen ◽  
Plant Uptake ◽  
Inorganic Nitrogen ◽  
Garden Soil ◽  
Laboratory Studies ◽  
Vaccinium Angustifolium ◽  
Nitrogen Levels ◽  
Lowbush Blueberry

Soil ammonium and nitrate in the top 15 cm of soil were monitored after application of ammonium nitrate and ammonium sulfate to plots at 14 PF (previously fertilized) and 12 NF (never fertilized) lowbush blueberry (Vaccinium angustifolium Ait.) stands representing a range of soil types and management histories. Overall, nitrate values in unfertilized and ammonium sulfate plots were higher at PF than at NF sites, suggesting greater nitrification at PF sites. In laboratory incubation studies, nitrification proceeded immediately in soil from a PF site, but only after a 4-wk lag in that from an adjacent NF site. Nitrification rates were low compared to that in a garden soil (pH 6.6). N-Serve inhibited nitrification in both soils. In ammonium nitrate plots, "excess" N values (N values in fertilized plots minus values in unfertilized plots) were higher for PF than for NF sites, suggesting greater immobilization, plant uptake or loss of N at NF sites. There was no evidence, in laboratory studies, of immobilization of added N by soil from either type of site. Rhizome N concentration increased significantly in response to fertilization at an NF site, but not at a PF site. Key words: Blueberry (lowbush), fertilizer and soil nitrogen

The effect of temperature and strain rate on the tensile strength of a fast-gas-cooled uranium-2 wt% molybdenum alloy

1985 ◽  
Vol 132 (2) ◽  
pp. 181-191 ◽  
Author(s):  
G.A.C. Boyd ◽  
J. Harding ◽  
P.A. Bleasdale ◽  
K. Dunn ◽  
G.I. Turner
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Molybdenum Alloy ◽  
Effect Of Temperature

Soil chemistry changes after 27 years under four tree species in southern Ontario

1989 ◽  
Vol 19 (12) ◽  
pp. 1648-1650 ◽  
Author(s):  
Elizabeth Anne France ◽  
Dan Binkley ◽  
David Valentine
Keyword(s):  
Forest Floor ◽  
Soil Chemistry ◽  
Mineral Soil ◽  
White Spruce ◽  
Stand Development ◽  
Acid Neutralization ◽  
White Pine ◽  
Southern Ontario ◽  
Silver Maple ◽  
Paper Birch

After 27 years of stand development, the accumulated forest floor under replicated plots of white pine (Pinusstrobus L.), white spruce (Piceaglauca (Moench) Voss), paper birch (Betulapapyrifera Marsh.), and silver maple (Acersaccharinum L.) ranged from 240 g/m2 under maple to 3680 g/m2 under white pine. Forest floor pH ranged from a low under maple of 3.7 to a high under white spruce of 5.9. No significant differences were found in pH in 0–15 cm depth mineral soil; however, substantial differences in the acid neutralization capacities were evident among species, with soils under maple showing the lowest capacity to resist further acidification.

The association of dry-matter yield with nitrogen and soluble-carbohydrate concentration in perennial ryegrass (Lolium perenne L.)

1979 ◽  
Vol 93 (3) ◽  
pp. 657-667 ◽  
Author(s):  
J. Valentine ◽  
A. H. Charles
Keyword(s):  
Nitrogen Concentration ◽  
High Yield ◽  
Soluble Carbohydrate ◽  
Nitrogen Application ◽  
Simple Correlation ◽  
Nitrogen Levels ◽  
Carbohydrate Concentration ◽  
Growth Room ◽  
Selection For ◽  
Low Nitrogen

SUMMARYThe associations between yield, nitrogen and soluble-carbohydrate concentration within S. 23 perennial ryegrass were investigated at three levels of nitrogen application. Controlled growth room conditions were used.The simple correlation between yield and nitrogen concentration was negative at the low rate of nitrogen application, not present at the intermediate rate of nitrogen and positive though not significant at the high rate of nitrogen. Yield and soluble-carbohydrate concentration were only correlated (positively) at the low nitrogen rate.At low nitrogen there were ‘efficient’ genotypes with relatively high yield and low nitrogen concentration. ‘Inefficient’ genotypes had relatively low yields and high nitrogen concentration. The majority of genotypes were neither markedly efficient or inefficient. The efficient genotypes at low nitrogen maintained their yield advantage at higher nitrogen levels with average nitrogen concentration and high numbers of tillers. Inefficient genotypes remained relatively stable in yield, numbers of tillers and nitrogen concentration.Partial correlation indicated an underlying high degree of dependence between yield, nitrogen and soluble-carbohydrate concentration at all nitrogen levels. The association of yield and nitrogen concentration showed a similar trend over nitrogen levels to that obtained using simple correlation. Yield and soluble-carbohydrate concentration were positively related, and nitrogen and soluble-carbohydrate concentration inversely related, when the effects of the remaining attribute were eliminated.Data extracted from Lee et al. (1977) confirmed that yield and nitrogen concentration for varieties under field conditions varied with level of nitrogen application in a similar manner to genotypes in the controlled growth room. The variety (Melle) could be characterized as being particularly efficient.Both sets of results indicate that selection for high yield of nitrogen in herbage can best be achieved through selection for yield alone.

Sulphur metabolism in sheep. IV. The effect of a varied dietary sulphur content on some body fluid sulphate levels and on the utilization of urea-supplemented roughage by sheep

1969 ◽  
Vol 20 (4) ◽  
pp. 759 ◽  
Author(s):  
AC Bray ◽  
JA Hemsley
Keyword(s):  
Body Fluid ◽  
Parotid Saliva ◽  
Crude Fibre ◽  
Nitrogen Levels ◽  
Residual Nitrogen ◽  
Inorganic Sulphate ◽  
Sulphate Sulphur ◽  
Mineral Mixture ◽  
Concentration Changes ◽  
Low Nitrogen

A diet composed of oaten hulls, urea, and mineral mixture was shown to be deficient in sulphur with respect to the nutrition of sheep. Sulphate supplements to the diet increased both crude fibre digestion and nitrogen and sulphur retention. They also increased the concentration of inorganic sulphate in the blood and the levels of total sulphur and total sulphate sulphur in the parotid saliva, but decreased blood urea nitrogen levels and the concentration of residual nitrogen and residual sulphur (protein fraction) in the parotid saliva. The effect of these concentration changes is discussed with particular reference to the feeding of sheep on low sulphur, low nitrogen forages.

Competition between skeleton weed (Chondrila juncea L) and cereals in relation to nitrogen supply

1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
LF Myers ◽  
J Lipsett
Keyword(s):  
Crop Yields ◽  
Nitrogen Supply ◽  
Weed Competition ◽  
Nitrogen Application ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Grain Nitrogen ◽  
Low Nitrogen ◽  
Yield Of Oats ◽  
Plant Growth Regulating Substances

The effect of skeleton weed competition on the yield of wheat and oats was investigated in seasons when rainfall was plentiful. Nitrogen was found to be the major factor limiting crop yields. In soils with comparable nitrogen-supplying powers, skeleton weed density governed the crop's response to applied nitrogen. Competition between skeleton weed and crop was severe at low nitrogen levels, but minor at the high nitrogen levels achieved either by nitrogen application, or when the crop followed a legume-rich pasture. Competition had its effect early in the crop's growth. Temporary removal of competition, by spraying with plant growth regulating substances (JICPA) at different times, was used to determine when competition was critical, and measure its effects. Skeleton weed reduced nitrogen supply early in the crop's growth, and so depressed yield. An application of 1 lb MCPA per acre in the fallow 54 days before sowing, or 10 days after crop emergence, increased the yield of oats from 710 to 1350 lb grain per acre: a response equal to that from 32 lb nitrogen per acre applied at planting in the same experiment. In each case, the response to spraying at the different times was analogous to the effect of a nitrogen application at these times. Early spraying gave responses in yield; later spraying gave responses in grain nitrogen. The results provide a new estimate of the reduction in crop yield due to skeleton weed.

A Study on the Effect of the Temperature on Mechanical Properties of H90 Copper Strip

2019 ◽  
Vol 950 ◽  
pp. 65-69
Author(s):  
Sun Fei ◽  
Xu Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Effect Of Temperature ◽  
Basic Material ◽  
Copper Strip ◽  
Study Results ◽  
Different Temperatures ◽  
Strip Test

In order to study the effect of temperature on the mechanical properties of H90 copper strip material, the H90 copper strip test pieces were heated to different temperatures (20~600 °C) for tensile test; the yield strength, tensile strength, elastic modulus and elongation of H90 copper strip at different temperatures were obtained. Based on the test results, the empirical models of yield strength, tensile strength, elastic modulus of H90 copper strip at high temperature were established; the test showed that, with the increase of temperature, the yield strength, tensile strength and elastic modulus of H90 copper strip decreased greatly, and the elongation after fracture first increased-decreased-increased at 20~600 °C. The study results in this paper provide basic material data for analyzing the effect of temperature on the continuous firing of firearms and other weapons.

Sign in / Sign up

Export Citation Format

Share Document