The growth of the lucerne plant after cutting: I. The effects of cutting at different stages of maturity and at different intensities

1968 ◽  
Vol 19 (4) ◽  
pp. 517 ◽  
Author(s):  
GJ Leach
Keyword(s):  
Dry Matter ◽  
Shoot Growth ◽  
Extension Growth ◽  
Grazing Management ◽  
Shoot Number ◽  
Shoot Size ◽  
Shoot Growth Rate ◽  
Main Effects ◽  
Pasture Plants

Variation in shoot number, shoot size, and yield of dry matter occurring in the regrowth from lucerne plants cut at different stages of maturity and at different intensities is reported. The main effects of the treatments arose through variation in shoot number and changes in the time at which each shoot commenced extension growth; a linear regression utilizing this information about the population of shoots accounted for nearly all the variation in yield. Less severe, or later, cutting resulted in greater yields of dry matter in a 4 week period of regrowth. Changes in shoot number and shoot size both contributed to the variation in the yield of regrowth. Shoot size was mainly determined by the time at which the shoot resumed extension growth, and once such growth was resumed the shoot growth rate was apparently independent of the cutting treatment applied. The results are discussed in relation to currently held concepts on the role of "reserves" and of residual leaf area in promoting the regrowth of pasture plants. The development of lucerne adapted to grazing management is also considered.

Growth and Development of Field Horsetail (Equisetum arvenseL.)

Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 271-275 ◽  
Author(s):  
George Marshall
Keyword(s):  
Growth And Development ◽  
Dry Matter ◽  
Shoot Growth ◽  
Equisetum Arvense ◽  
Shoot Height ◽  
Potted Plants ◽  
Shoot Number ◽  
Herbicide Treatments ◽  
Shoot Growth Rate ◽  
Rhizome System

The growth and development of field horsetail (Equisetum arvenseL. # EQUAR) was measured outdoors using potted plants grown from one-node rhizome fragments. Shoot growth rate increased slowly after planting in March, accelerating to a maximum during July with maximas for shoot height during August and shoot number in September. Rhizome system growth rates initially followed a similar pattern to that of the shoots achieving a maximum during July. Dry matter accumulated in the rhizomes until October and declined thereafter throughout the winter. Tubers initiated during August grew in size and number until November, well beyond the period of active shoot growth and onset of senescence. The characteristics of the growth and development of field horsetail are discussed in relation to achieving weed control via cultural and herbicide treatments.

Shoot growth on lucerne plants cut at different heights

1970 ◽  
Vol 21 (4) ◽  
pp. 583 ◽  
Author(s):  
GJ Leach
Keyword(s):  
Medicago Sativa ◽  
Dry Matter ◽  
Shoot Growth ◽  
Total Yield ◽  
Extension Growth ◽  
Medicago Sativa L ◽  
Cutting Height ◽  
Two Stages

Lucerne (Medicago sativa L.) plants grown to two stages of maturity were cut at 2, 5, or 10 cm above the crown. In addition, the leaf on the stubble and on basal shoots was either removed or retained. The change in the number and size of the regrowth shoots growing from different heights above the crown, and the total yield of dry matter, were observed for 4 weeks after cutting. Nearly all the regrowth shoots arose from very near to the crown, either on the crown itself or from within the first 2 cm above it, so that cutting at higher levels increased shoot numbers only slightly. Also most of the shoots arising from near the crown resumed extension growth earlier, and therefore grew larger, than the shoots arising from higher positions. In general the growth of shoots from one stubble segment was not influenced by whether segments were still present above. Increasing the cutting height above 2 cm consequently produced little effect on the yield of dry matter 2 and 4 weeks after cutting. Retaining stubble leaf and basal shoot leaf increased the shoot yield 2 and 4 weeks later, because the basal shoots resuming growth first grew larger than those on plants from which leaves were removed. The effect of retaining leaves was independent of the stage of maturity when the plants were cut and of the cutting height.

scholarly journals Growth of Rooted `Gala' Apple Microcuttings ex Vitro as Influenced by Initial Adventitious Root Count

HortScience ◽  
1993 ◽  
Vol 28 (6) ◽  
pp. 664-666 ◽  
Author(s):  
Dennis P. Stimart ◽  
James F. Harbage
Keyword(s):  
Adventitious Root ◽  
Significant Interaction ◽  
Adventitious Roots ◽  
Shoot Growth ◽  
Ex Vitro ◽  
Subsequent Growth ◽  
Root And Shoot Growth ◽  
Main Effects

The role of the number of adventitious roots of Malus domestics Borkh. `Gala' microcuttings in vitro on ex vitro root and shoot growth was investigated. Root initiation treatments consisted of IBA at 0, 0.15, 1.5, 15, and 150 μm in factorial combination with media at pH 5.5, 6.3, and 7.0. IBA concentrations significantly influenced final root count and shoot fresh and dry weights, but not plant height, leaf count, or root fresh and dry weights at 116 days. Between 0 and 0.15 μm IBA, final root counts were similar, but at 1.5, 15, and 150 μm IBA, root counts increased by 45%, 141%, and 159%, respectively, over the control. The pH levels did not affect observed characteristics significantly. There was no significant interaction between main effects. A significant positive linear relationship was found between initial and final root count. The results suggest a limited association between high initial adventitious root count and subsequent growth. Chemical name used: 1 H -indole-3-butyric acid (IBA).

scholarly journals Effects of Planting Density on Water Use and Productivity of Pearl Millet (Pennisetum Typhoides) Grown on Stored Water. I. Growth of Roots and Shoots

1984 ◽  
Vol 20 (3) ◽  
pp. 203-214 ◽  
Author(s):  
S. N. Azam-Ali ◽  
P. J. Gregory ◽  
J. L. Monteith
Keyword(s):  
Pearl Millet ◽  
Water Use ◽  
Dry Matter ◽  
Shoot Growth ◽  
Planting Density ◽  
Soil Cores ◽  
Physiological Basis ◽  
Pennisetum Typhoides ◽  
Different Populations

SUMMARYPearl millet (Pennisetum typhoides) was grown on stored water at Niamey, Niger, using three row spacings (38, 75 and 150 cm), to determine the physiological basis of exploitation and conservation of water by crops during drought Between 18 and 32 days after sowing, roots grew rapidly beneath all crops reaching 140 cm in the narrow spacing, but there were differences between crops in the pattern of growth. Soil cores and trench profiles indicated that plants in wider rows had fewer, deeper roots. Substantial differences in both the amount and pattern of shoot growth were recorded in the different populations. Initially growth was fastest at the narrow spacing but stopped by day 45 and eventually the wide spacing produced most dry matter due mainly to greater survival of tillers. The partitioning of above ground dry matter into vegetative and reproductive fractions was similar at all three spacings and was consistent with figures for comparable crops elsewhere. The important role of tillers is discussed in relation to the development and maintenance of a canopy.

Screening cereals for genotypic variation in efficiency of phosphorus uptake and utilisation

2002 ◽  
Vol 53 (3) ◽  
pp. 295 ◽  
Author(s):  
L. D. Osborne ◽  
Z. Rengel
Keyword(s):  
Dry Matter ◽  
Shoot Growth ◽  
Genotypic Variation ◽  
Phosphorus Uptake ◽  
Dry Weight ◽  
P Efficiency ◽  
P Content ◽  
Shoot Growth Rate ◽  
Utilisation Efficiency ◽  
P Supply

One hundred and six Australian cereal genotypes, including wheat, triticale, and rye, were screened for their ability to take up and utilise soluble phosphorus at different rates of P supply. Plants were screened in outdoor tanks irrigated at regular intervals with nutrient solution amended with 3 rates of P. Genotypes were ranked according to the following 3 criteria: shoot growth at deficient P supply, the relative shoot growth rate (dry weight at deficient P/dry weight at sufficient P), and phosphorus utilisation efficiency (amount of dry matter produced per unit of P accumulated in shoots corrected for seed P content). Considerable genotypic variation in growth and P utilisation efficiency was found in the cereal germplasm. Rye and triticale were generally more efficient in taking up and utilising P than wheat at low rates of P supply. Wheat genotypes Egret and Durati showed relatively high, and genotype Cadoux relatively low, P efficiency.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

The Role of Positive and Negative Affectivity in Healthy and Unhealthy Work-Related Behavior and Experiences

2019 ◽  
Vol 26 (2) ◽  
pp. 56-67 ◽  
Author(s):  
Hanna Hofmann ◽  
Carl-Walter Kohlmann
Keyword(s):  
Negative Affectivity ◽  
Coping Behavior ◽  
Common Method ◽  
Positive Affectivity ◽  
Work Related ◽  
Teacher Students ◽  
And Behaviors ◽  
Main Effects ◽  
Positive And Negative Affectivity

Abstract. Positive affectivity (PA) and negative affectivity (NA) are basic traits that affect work-related perceptions and behaviors and should be considered in any assessment of these variables. A quite common method to assess healthy or unhealthy types of work-related perceptions and behaviors is the questionnaire on Work-Related Coping Behavior and Experience Patterns (WCEP). However, the association of PA and NA with WCEP remained unclear. In a sample of teachers, physiotherapists, and teacher students ( N = 745; Mage = 35.07, SD = 12.49; 78% females), we aimed to identify the relevance of these basic traits. After controlling for age, gender, and type of occupation, we found main effects of PA and NA, with the specific combination of PA and NA being decisive for predicting the assignment to a WCEP type. The results highlight the need to include PA and NA in future assessments with the WCEP questionnaire.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

Grazed pasture parameters. I. Pasture dry-matter production and availability in a stocking rate and grazing management experiment with dairy cows

1966 ◽  
Vol 67 (2) ◽  
pp. 199-210 ◽  
Author(s):  
A.G. Campbell
Keyword(s):  
Dairy Cow ◽  
Dry Matter ◽  
Grazing Management ◽  
Dry Matter Production ◽  
Small Scale ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Pasture Production ◽  
Grazed Pasture ◽  
Matter Production

1. Net pasture dry matter production and available pasture dry matter were measured over 3 years in a small-scale replica of the study of the effects of dairy cow grazing management and stocking rate reported by McMeekan & Walshe (1963).2. The four treatments were(i) Controlled rotational grazing, light stocking rate (0.95 cows/acre).(ii) Controlled rotational grazing, heavy stocking rate (1.19 cows/acre).(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cows/acre).(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).3. The pasture measurement technique employed measured net pasture production (gains through new growth minus losses from all sources). It is argued that this parameter, rather than absolute pasture production, governs the changes in the dry matter feed supply to the grazing animal.

scholarly journals Epistasis for Three Grain Yield Components in Rice (Oryxa sativa L.)

Genetics ◽  
1997 ◽  
Vol 145 (2) ◽  
pp. 453-465 ◽  
Author(s):  
Zhikang Li ◽  
Shannon R M Pinson ◽  
William D Park ◽  
Andrew H Paterson ◽  
James W Stansel
Keyword(s):  
Grain Yield ◽  
Complex Traits ◽  
Yield Components ◽  
Genetic Basis ◽  
Kernel Weight ◽  
Progeny Testing ◽  
Grain Yield Components ◽  
Main Effects ◽  
Grain Number Per Panicle

The genetic basis for three grain yield components of rice, 1000 kernel weight (KW), grain number per panicle (GN), and grain weight per panicle (GWP), was investigated using restriction fragment length polymorphism markers and F4 progeny testing from a cross between rice subspecies japonica (cultivar Lemont from USA) and indica (cv. Teqing from China). Following identification of 19 QTL affecting these traits, we investigated the role of epistasis in genetic control of these phenotypes. Among 63 markers distributed throughout the genome that appeared to be involved in 79 highly significant (P < 0.001) interactions, most (46 or 73%) did not appear to have “main” effects on the relevant traits, but influenced the trait(s) predominantly through interactions. These results indicate that epistasis is an important genetic basis for complex traits such as yield components, especially traits of low heritability such as GN and GWP. The identification of epistatic loci is an important step toward resolution of discrepancies between quantitative trait loci mapping and classical genetic dogma, contributes to better understanding of the persistence of quantitative genetic variation in populations, and impels reconsideration of optimal mapping methodology and marker-assisted breeding strategies for improvement of complex traits.

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