A STUDY OF THE DEGREE OF CREEPING ROOTEDNESS IN RELATION TO BREEDING INTERMEDIATE WHEATGRASS

1965 ◽  
Vol 45 (5) ◽  
pp. 467-470
Author(s):  
T. Lawrence
Keyword(s):  
Dry Matter ◽  
Ground Cover ◽  
The Other ◽  
Dry Matter Yield ◽  
Intermediate Wheatgrass ◽  
Agropyron Intermedium ◽  
Clonal Lines ◽  
Root Character ◽  
Relationship Of ◽  
The Relationship

Twenty clonal lines of intermediate wheatgrass, Agropyron intermedium (Host.) Beauv., were selected to represent the range in creep development to be found in a breeding nursery. Polycross progenies of these clonal lines were studied to determine the relationship of the degree of creeping rootedness of the 20 clones with the dry matter yield, basal ground cover, and winterkilling of their polycross progenies. This was done to determine the emphasis that should be placed on selecting for or against the creeping root character in a breeding program.No strong relationships between creep and the other characteristics were found on either dryland or irrigated land. However, there was some indication under irrigation that better initial stands were obtained with lines showing reduced creep and that these same lines were more subject to invasion by weeds in later years.It is apparent that the degree of creeping rootedness requires little consideration in breeding intermediate wheatgrass.

EFFECT OF NITROGEN FERTILIZER AND CLIPPING FREQUENCY ON THE DRY MATTER YIELD AND PERSISTENCY OF INTERMEDIATE WHEATGRASS

1969 ◽  
Vol 49 (4) ◽  
pp. 435-446 ◽  
Author(s):  
T. Lawrence ◽  
R. Ashford
Keyword(s):  
Regression Analysis ◽  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Statistical Approach ◽  
Ground Cover ◽  
N Fertilizer ◽  
Dry Matter Yield ◽  
Intermediate Wheatgrass ◽  
Agropyron Intermedium ◽  
Management Factors

The effects of six rates of N fertilizer and five frequencies of clipping on the dry matter yield and persistency of irrigated intermediate wheatgrass, Agropyron intermedium (Host.) Beauv., were studied during 1961–62 at one site, and 1963–65 at a second site.The dry matter yield increased with increasing rates of N fertilizer, and with longer intervals between clippings. Highest yields were obtained with the 375-kg/ha rate of N fertilizer and the 8-week clipping interval.Fertilizer level did not have a significant effect on either the basal ground cover of grass or the degree of winter injury suffered by intermediate wheat-grass. However, clipping frequency was closely related to both of these factors.Application of a regression analysis to the study of significant interactions among management factors proved to be a very useful statistical approach.

THE PRODUCTIVITY OF INTERMEDIATE WHEATGRASS AS AFFECTED BY INITIAL HARVEST DATES AND RECOVERY PERIODS

1966 ◽  
Vol 46 (1) ◽  
pp. 9-15 ◽  
Author(s):  
T. Lawrence ◽  
R. Ashford
Keyword(s):  
Dry Matter ◽  
Recovery Period ◽  
Harvest Date ◽  
Dry Matter Yield ◽  
Intermediate Wheatgrass ◽  
Agropyron Intermedium ◽  
Harvest Dates ◽  
Critical Phase

The productivity of Agropyron intermedium (Host.) Beauv., as influenced by variation in the date of initial harvest and length of recovery period between cuttings, was studied on irrigated land over a 2-year period. Ten initial cutting dates, each spaced 3 days apart, and two recovery periods of 21 days and 42 days, were used. Delaying the initial harvest date resulted in progressively greater dry-matter yields at the first cutting and progressively lower yields at the second cutting. Earlier and later initial cuttings gave higher yields than at the shotblade stage when this species seems to be in a critical phase of development. Grass given a 42-day recovery period between cuttings produced an average dry-matter yield of 3.63 tons per acre over the 2-year period, and 1.71 tons of root material per acre in the first crop year. Comparable yields in tons per acre for grass given a 21-day recovery period were 2.29 for dry matter and 1.31 for root material. Likewise, grass given a 21-day recovery period showed a rapid stand deterioration, whereas that given a 42-day recovery period did not show a reduction. Intermediate wheatgrass is high-yielding if managed properly and not abused by intensive cutting or grazing. It appears to be more suitable for hay production than for pasture.

Influence of zinc supply on the phytotoxicity of cadmium in maize (Zea mays L.) grown on cadmium-contaminated soil

2012 ◽  
Vol 60 (1) ◽  
pp. 37-46 ◽  
Author(s):  
M. Khurana ◽  
B. Kansal
Keyword(s):  
Dry Matter ◽  
Sandy Loam ◽  
Cadmium Concentration ◽  
Dry Matter Yield ◽  
Phytotoxic Effect ◽  
Loam Soil ◽  
Relationship Of ◽  
The Relationship ◽  
Zinc Application ◽  
Cadmium Contaminated Soil

Zinc and cadmium have been found to interact with each other differently under different conditions. The zinc supply may enhance or offset the phytotoxicity of Cd. Therefore, in a pot experiment, a sandy loam soil (Typic Ustipsamments) was treated with cadmium at rates of 0, 10, 20 and 40 mg kg−1 and with zinc at rates of 0 and 20 mg kg−1 soil to assess their effect on dry matter yield and the concentrations of Cd and micronutrients. There was a significant decrease in dry matter yield due to the phytotoxic effect of Cd. The dry matter yield was not affected by the application of zinc at any rate of Cd application. The concentration and uptake of Cd in the crop increased gradually at increasing rates of cadmium application. The increase in cadmium concentration was greater in the presence of zinc than in its absence. This suggests that the effect of soilapplied Zn is reflected in the enhancement of the Cd content in plants. Thus, zinc application cannot offset the toxic effect of Cd. The relationship of Cd with Zn and Fe was synergistic at all rates of Cd application, whereas Mn and Cu exhibited an antagonistic relationship.

PRODUCTIVITY OF INTERMEDIATE WHEATGRASS AS INFLUENCED BY DATE OF INITIAL CUTTING, HEIGHT OF CUTTING, AND N FERTILIZER

1973 ◽  
Vol 53 (2) ◽  
pp. 295-301 ◽  
Author(s):  
T. LAWRENCE
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Matter ◽  
N Fertilizer ◽  
Protein Yield ◽  
Dry Matter Yield ◽  
Crude Protein Content ◽  
Intermediate Wheatgrass ◽  
Agropyron Intermedium ◽  
Cutting Height

The interactions of three dates of initial cutting followed by one or two subsequent cuttings, three heights of cutting, and four fertilizer treatments on the dry matter yield, crude protein content, and crude protein yield of intermediate wheatgrass (Agropyron intermedium (Host.) Beauv.) were studied on irrigated land for 2 yr. Cutting on 15 June during the shot blade stage resulted in severe summer killing. Variation in height of cutting and N fertilizer levels resulted in differences in annual yields. On the basis of the 2-yr mean yield, however, these differences were masked by interaction of these factors with years. Crude protein content of the forage at cut 1 decreased with the deferment of the first cut, was not influenced by height of cutting, but increased with increases in N fertilizer. The yield of crude protein increased with increasing levels of N fertilizer and showed significant interactions for year × date of initial cutting × fertilizer and years × date of initial cutting × height of cutting. Split applications of N fertilizer showed no advantage over a single spring application in either year.

scholarly journals On Newcomb's method of investigating periodicities and its application to Brückner's weather cycle

1914 ◽  
Vol 90 (619) ◽  
pp. 349-355
Keyword(s):  
Thermal Radiation ◽  
The Other ◽  
New Method ◽  
Critical Examination ◽  
Numerical Work ◽  
Average Value ◽  
Other Hand ◽  
Relationship Of ◽  
The Relationship ◽  
Great Simplicity

During the last few years of his life Prof. Simon Newcomb was keenly interested in the problem of periodicities, and devised a new method for their investigation. This method is explained, and to some extent applied, in a paper entitled "A Search for Fluctuations in the Sun's Thermal Radiation through their Influence on Terrestrial Temperature." The importance of the question justifies a critical examination of the relationship of the older methods to that of Newcomb, and though I do not agree with his contention that his process gives us more than can be obtained from Fourier's analysis, it has the advantage of great simplicity in its numerical work, and should prove useful in a certain, though I am afraid, very limited field. Let f ( t ) represent a function of a variable which we may take to be the time, and let the average value of the function be zero. Newcomb examines the sum of the series f ( t 1 ) f ( t 1 + τ) + f ( t 2 ) f ( t 2 + τ) + f ( t 3 ) f ( t 3 + τ) + ..., where t 1 , t 2 , etc., are definite values of the variable which are taken to lie at equal distances from each other. If the function be periodic so as to repeat itself after an interval τ, the products are all squares and each term is positive. If, on the other hand, the periodic time be 2τ, each product will be negative and the sum itself therefore negative. It is easy to see that if τ be varied continuously the sum of the series passes through maxima and minima, and the maxima will indicated the periodic time, or any of its multiples.

Effect of weeds and nitrogen fertiliser on yield and grain protein concentration of wheat

1996 ◽  
Vol 36 (4) ◽  
pp. 443 ◽  
Author(s):  
MG Mason ◽  
RW Madin
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Dry Matter ◽  
Protein Concentration ◽  
The Other ◽  
Grain Protein ◽  
Dry Matter Yield ◽  
Wheat Grain ◽  
Grain Protein Concentration ◽  
Nitrogen Fertiliser

Field trials at Beverley (19911, Salmon Gums (1991; 2 sites) and Merredin (1992; 2 sites), each with 5 rates of nitrogen (N) and 3 levels of weed control, were used to investigate the effect of weeds and N on wheat grain yield and protein concentration during 1991 and 1992. Weeds in the study were grasses (G) and broadleaf (BL). Weeds reduced both vegetative dry matter yield and grain yield of wheat at all sites except for dry matter at Merredin (BL). Nitrogen fertiliser increased wheat dry matter yield at all sites. Nitrogen increased wheat grain yield at Beverley and Merredin (BL), but decreased yield at both Salmon Gums sites in 1991. Nitrogen fertiliser increased grain protein concentration at all 5 sites-at all rates for 3 sites [Salmon Gums (G) and (BL) and Merredin (G)] and at rates of 69 kg N/ha or more at the other 2 sites [Beverley and Merredin (BL)]. However, the effect of weeds on grain protein varied across sites. At Merredin (G) protein concentration was higher where there was no weed control, possibly due to competition for soil moisture by the greater weed burden. At Salmon Gums (G), grain protein concentration was greater when weeds were controlled than in the presence of weeds, probably due to competition for N between crop and weeds. In the other 3 trials, there was no effect of weeds on grain protein. The effect of weeds on grain protein appears complex and depends on competition between crop and weeds for N and for water at the end of the season, and the interaction between the two.

scholarly journals Physical Activity and Psychological Well-Being: Testing Alternative Sociological Interpretations

1990 ◽  
Vol 7 (4) ◽  
pp. 329-346 ◽  
Author(s):  
William McTeer ◽  
James E. Curtis
Keyword(s):  
Physical Activity ◽  
Socioeconomic Status ◽  
Social Interaction ◽  
Physical Fitness ◽  
Well Being ◽  
The Other ◽  
Positive Zero ◽  
Psychological Well Being ◽  
Relationship Of ◽  
The Relationship

This study examines the relationship between physical activity in sport and feelings of well-being, testing alternative interpretations of the relationship between these two variables. It was expected that there would be positive relationships between physical activity on the one hand and physical fitness, feelings of well-being, social interaction in the sport and exercise environment, and socioeconomic status on the other hand. It was also expected that physical fitness, social interaction, and socioeconomic status would be positively related to psychological well-being. Further, it was expected that any positive zero-order relationship of physical activity and well-being would be at least in part a result of the conjoint effects of the other variables. The analyses were conducted separately for the male and female subsamples of a large survey study of Canadian adults. The results, after controls, show a modest positive relationship of physical activity and well-being for males but no such relationship for females. The predicted independent effects of the control factors obtained for both males and females. Interpretations of the results are discussed.

THE RELATIONSHIP OF THE SODIUM, POTASSIUM, AND CHLORIDE CONCENTRATION OF THE FEEDING TO THE WEIGHT GAIN OF PREMATURE INFANTS

PEDIATRICS ◽  
1962 ◽  
Vol 30 (6) ◽  
pp. 909-916
Author(s):  
Herbert I. Goldman ◽  
Samuel Karelitz ◽  
Hedda Acs ◽  
Eli Seifter
Keyword(s):  
Weight Gain ◽  
Sodium Chloride ◽  
Human Milk ◽  
Premature Infants ◽  
Chloride Concentration ◽  
The Other ◽  
Milk Formula ◽  
Sodium Potassium ◽  
Relationship Of ◽  
The Relationship

One hundred four healthy premature infants, of birth weight 1,000 to 1,800 gm, were fed one of five feedings: (1) human milk; (2) human milk plus 13 meq/l of sodium chloride; (3) human milk plus 13 meq/l of sodium chloride and 18 meq/l of potassium chloride; (4) a half-skimmed cows milk formula; and (5) a partially-skimmed vegetable oil, cows milk formula. The infants fed any of the three human milk formulas gained weight at a slower rate than the infants fed either of the two cows milk formulas. Infants whose diets were changed from unmodified human milk to the half-skimmed cows milk gained large amounts of weight, and at times were visibly edematous. Infants whose diets were changed from the human milks with added sodium chloride, to the half-skimmed cows milk, gained lesser amounts of weight and did not become edematous. The infants fed the two cows milk diets gained similar amounts of weight, although one diet provided 6.5 gm/kg/day, the other 3.1 gm/kg/day of protein.

Een beetje onsterfelijk

Lampas ◽  
2019 ◽  
Vol 52 (4) ◽  
pp. 437-452
Author(s):  
Gerard Boter
Keyword(s):  
Present Article ◽  
The Other ◽  
Relationship Of ◽  
The Relationship ◽  
Immortality Of The Soul

Summary The present article discusses three hotly debated interpretational issues in Diotima´s speech in Plato´s Symposium. The first of these is the relationship of Diotima´s speech to other dialogues, such as the Phaedo and the Republic, with regard to the immortality of the soul. It is argued that there is no discrepancy at all, because the immortality of the soul does not play any role in the Symposium. The second issue is the nature of the three classes of posterity: biological, spiritual and philosophical. Whereas the posterity of the first two classes can be relatively easily defined, the character of the philosopher´s posterity, ‘true virtue’, remains rather vague. It may consist in dialectical teaching of the Idea of Beauty by Socrates. Thirdly, it is argued that the philosopher´s immortality differs only gradually from the immortality of the other two classes, that is, the philosopher as a man only survives by means of his posterity.

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