scholarly journals The Growth and Composition of Wool III. Variations in the Sulphur Content of Wool

1965 ◽  
Vol 18 (3) ◽  
pp. 671 ◽  
Author(s):  
PJ Reis
Keyword(s):  
Growth Rates ◽  
Dry Weight ◽  
Sulphur Content ◽  
Wool Growth ◽  
Different Levels

The sulphur content of wool was measured during experiments in which the nutritive status of sheep was altered by changes in the amount or composition of the diet. Three experiments were carried out, involving 13 sheep and five diets given at different levels of feeding. Wool grown on delineated areas was collected and its clean dry weight and sulphur content were determined. Wool growth rates varied between 0�3 and 1� 8 mg clean dry wool/cm2/day.

scholarly journals Selection of drought tolerant wheat genotypes by osmotic stress imposed at germination and early seedling stage

2018 ◽  
Vol 15 (2) ◽  
pp. 177-192
Author(s):  
RR Saha ◽  
A Hannan ◽  
A Nessa ◽  
MA Malek ◽  
MR Islam
Keyword(s):  
Osmotic Stress ◽  
Dry Weight ◽  
Seedling Stage ◽  
Metabolic Efficiency ◽  
Wheat Genotypes ◽  
Shoot Dry Weight ◽  
Vigour Index ◽  
Peg Treatment ◽  
Early Seedling ◽  
Different Levels

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)

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

1989 ◽  
Vol 40 (2) ◽  
pp. 293 ◽  
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.

The use of urea-molasses supplements for sheep grazing semi-arid tropical pastures

1974 ◽  
Vol 14 (66) ◽  
pp. 17 ◽  
Author(s):  
KW Entwistle ◽  
G Knights
Keyword(s):  
Growth Rates ◽  
Reproductive Factors ◽  
Experimental Period ◽  
Dry Season ◽  
Sheep Grazing ◽  
Tropical Pastures ◽  
Nitrogen Levels ◽  
Wool Growth ◽  
Urea Group ◽  
Semi Arid

The performance of unsupplemented Merino ewes grazing dry season semi-arid tropical pastures was compared with that of other sheep supplemented with either urea-molasses or molasses. Over the experimental period from September 1970 until late January 1971 mean daily intakes per head of urea and molasses respectively were: low urea group, 11.7 g and 35.1 g; high urea group, 15.2 g and 45.6 g; molasses, 38.9 g. Monthly estimates of the proportions of animals consuming the supplement over the period September to January varied from: urea-molasses-71 per cent to 97 per cent; molasses-75 per cent to 96 per cent. Unsupplemented sheep lost significantly more liveweight than did supplemented groups in the period September to February. However, during the period of greatest nutritional stress from December to February, sheep recewing molasses lost significantly more weight than did those supplemented with urea-molasses, and liveweight loss was greater in the low urea group than in the high urea group. Wool growth rates were significantly higher in groups receiving urea-molasses, with highest wool growth rates in animals on the high level of urea. Total fleece weights were unaffected by treatment as were the reproductive factors examined. Faecal nitrogen levels declined until the onset of pasture regrowth in February and were associated with low digestibility of the available forage. Compensatory liveweight gains following pasture regrowth outweighed any advantage of the dry season supplementation. It was concluded that urea-molasses supplements were of little direct benefit to sheep grazing these pastures.

Relationships Between RNA–DNA Ratio, Prey Density, and Growth Rate in Atlantic Cod (Gadus morhua) Larvae

1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley
Keyword(s):  
Growth Rate ◽  
Nutritional Status ◽  
Growth Rates ◽  
Prey Density ◽  
Gadus Morhua ◽  
Slow Growth ◽  
Atlantic Cod ◽  
Larval Fish ◽  
Dry Weight ◽  
Dna And Rna

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod

Sulfur and methionine metabolism in sheep. III.* Excretion and retention of dietary and supplemented sulfur, and production responses to intraruminal infusions of DL-methionine

1979 ◽  
Vol 30 (6) ◽  
pp. 1185 ◽  
Author(s):  
PT Doyle ◽  
RJ Moir
Keyword(s):  
Amino Acid ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Methionine Metabolism ◽  
Sulfate Sulfur ◽  
Wool Growth ◽  
Methionine Supplementation ◽  
Different Levels ◽  
Basal Ration ◽  
Inorganic Sulfate

Two experiments were carried out to study the excretion and retention of nitrogen and sulfur when intraruminal infusions of DL-methionine were given to sheep. Merino wethers were fed on a 50:50 oaten chaff: lucerne chaff ration at different levels of dry matter intake (DMI), either as chaff or ground and pelleted, and with or without intraruminal infusions of DL-methionine. Liveweight gain in experiment 1, and the rate of wool growth and sulfur incorporation into wool were also measured. [35S]L-methionine was used to trace sulfur excretion from the supplement. Increasing the DMI increased (P < 0.001) nitrogen and sulfur excretion in both faeces and urine, but also increased (P < 0.001) the apparent retention of nitrogen and sulfur. The excretion of nitrogen and sulfur was not significantly affected by the form in which the basal ration was supplied, but sulfur retention did improve (P < 0.05) when the ration was given as chaff. DL-methionine supplements resulted in large increases (P < 0.001) in the excretion of total and inorganic sulfate sulfur in urine, and there was a tendency for urinary neutral sulfur excretion to increase. The amino acid supplement did not affect faecal sulfur excretion except at the lower level of feed intake in experiment 2. Differences in the amount of sulfur, from DL-methionine and [35S]L- methionine injections given into the rumen, excreted in faeces and urine indicate possible differences in the metabolism of the amino acid isomers. Increasing DMI resulted in improved (P < 0.001) rates of liveweight gain and wool growth; DL-methionine infusions had no effect. Further, estimates of sulfur incorporation into wool indicate that very little supplementary methionine was utilized at the follicular sites despite increased sulfur retention. The patterns of sulfur excretion suggest that the added methionine was rapidly and virtually completely dissimilated in the rumen. It is concluded that production responses to dietary methionine supplementation occur only under sulfur-deficient conditions or occasionally where degradation is avoided. _____________________ *Part II, Aust. J. Biol. Sci., 32: 65 (1979).

COMPARATIVE STUDIES OF NORTH AMERICAN AND EUROPEAN CULTURES OF THE ROOT ROT FUNGUS, FOMES ANNOSUS (FR.) COOKE

1955 ◽  
Vol 33 (5) ◽  
pp. 416-428 ◽  
Author(s):  
D. E. Etheridge
Keyword(s):  
Growth Rate ◽  
North American ◽  
Growth Rates ◽  
Root Rot ◽  
Linear Growth ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Cellulolytic Activity ◽  
Ph Optimum ◽  
Two Cultures

Cultures of Fames annosus originating in Europe could not be distinguished from those originating in North America either by colony appearance, growth rate, pH optimum, or cellulolytic activity. Three growth rate types on 2.5% malt agar were recognized and these are ascribed to individual variation rather than to host or geographical influences. Successive subculturing produced variants that fell into three growth classes. Half of the isolates displayed spontaneous, but reversible, changes in growth rate and colony appearance during subculturing and this is discussed from the standpoint of genetical and environmental influences. Cultures displaying different morphological characteristics and linear-growth rates differed little metabolically; each had a similar pH optimum ranging from 4.6 to 5.5, and each proved capable of altering the initial acidity of the medium to a reaction which was more suitable for growth. Two cultures were characterized by double pH optima at 4.6 and 5.5. Cultures having different linear-growth rates produced about the same dry-weight of mycelium on a cellulose substrate in a semisynthetic nutrient solution. On the basis of a statistical analysis of cellulose utilization by representative isolates it was impossible to distinguish between North American and European cultures.

Proximodistal leg regeneration in Carausius morosus: growth, intercalation and proximalization

Development ◽  
1988 ◽  
Vol 102 (1) ◽  
pp. 71-84
Author(s):  
A. Bart
Keyword(s):  
Growth Rates ◽  
Distal Part ◽  
Healing Process ◽  
Differential Growth ◽  
Carausius Morosus ◽  
Positional Value ◽  
Different Levels

The proximodistal epidermal organization of the regenerated insect leg has been studied by grafting between corresponding and noncorresponding levels of the pro- and metathoracic femur and tibia. The results have been studied quantitatively (growth rates of the associated parts and of unsegmented intercalary structures) and qualitatively (nature, length, polarity of intercalary structures). In grafts between equivalent levels, no intercalary structure is formed, but a differential growth has been observed, the distal one fifth of segments growing about 1.5 to 2 times more than the proximal one. In grafts between different levels, unsegmented intercalary structures are formed from the distal part which thereby acquires proximal characteristics (proximalization). However, distal tibial cells do not form femur in this process under an hypothetical femoral influence: there is no ‘dominance’ of femur over tibia. Some segmented intercalary structures have also been observed, but their formation cannot be related clearly to differences in the healing process. To explain proximalization, an hypothesis is presented suggesting that distal cells, which grow faster, would be the first to enter a period when positional value becomes labile and would then adapt to the proximal cells' value.

scholarly journals Effects of different levels of mulch and irrigation on growth traits and essential oil content of basil

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Fatemeh Nejatzadeh-Barandozi
Keyword(s):  
Essential Oil ◽  
Leaf Area ◽  
Wood Chip ◽  
Dry Weight ◽  
Wood Chips ◽  
Growth And Yield ◽  
Oil Yield ◽  
Fresh Weight ◽  
Essential Oil Yield ◽  
Different Levels

Ocimum basilicum L. is an herbaceous plant from the Labiate family that used fresh, as a spice, and as a medicinal plant. Mulch is technique capable of reducing evaporation from the surface of the soil in basil production systems; it has more impacts on yield and essential oil quality of a basil crop. This research was performed in order to study the effects of different mulch types and irrigation regimes on various growth parameters and the essential oil content of basil. Treatments included two mulch types (black plastic, wood chips, and control) and three irrigation levels (100, 80, and 60% of water requirements, calculated by evaporation pan class A), following a randomised complete block design with four replications. Results showed that the effect of irrigation on fresh weight, dry weight, leaf relative water content, leaf area, and essential oil yield was significant (P<0.05). The effect of mulch on fresh weight, dry weight, leaf area, inter-node distance, number of branches, and essential oil yield was significant (P<0.05). Interaction between irrigation and mulch on inter-node distance, fresh weight, dry weight, and leaf area was significant (P<0.05). This study identified wood chips as the best mulch treatment. The highest dry weight yield (38.35 g/plant) and the highest essential oil yield (82.83 L/ha) resulted when wood chip mulch was used in combination with irrigation at 100% of the water requirement. This combination also resulted in the highest water productivity in basil production.   Highlights - Different levels of irrigation alone did not always increase plant growth and yield of basil. - Different levels of mulch alone did not always increase plant growth and yield of basil. - Different levels of irrigation and mulch in combination used, increased, growth and essential oil yield of basil. - This study identified wood chips as the best mulch treatment. - The highest essential oil yield resulted with wood chip mulch and irrigation at 100% of the water requirement.

Sign in / Sign up

Export Citation Format

Share Document