Effects of close cutting and nitrogen fertilizer on growth of a Siratro (Phaseolus atropurpureus) pasture at Samford, south-eastern Queensland

1967 ◽  
Vol 7 (25) ◽  
pp. 157 ◽  
Author(s):  
RJ Jones
Keyword(s):  
Growth Rate ◽  
White Clover ◽  
Low Temperatures ◽  
Dry Matter ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Cutting Frequency ◽  
Cutting Interval ◽  
The Mean ◽  
Tropical Grass

Uninterrupted growth of Siratro (Phaseolus atropurpureus) in a Siratro-grass pasture was slow in spring, increased rapidly in mid-December, and attained a maximum growth rate of 79 lb dry matter an acre a day in February-March. The slow spring growth appeared to be associated with low temperatures. Yield and percentage of Siratro increased for at least 191 days after commencement of growth in spring. Yields of Siratro increased linearly from 1400 lb to 6500 lb dry matter an acre as the cutting interval increased from 4 to 16 weeks. Yields of other species declined as the cutting interval increased. With a 4-weekly cutting regime, the stand of Siratro was greatly reduced after one season. Lucerne subjected to the same treatment gave higher yields and the stand remained good. Urea reduced the mean yield of Siratro by 16 per cent and 33 per cent at the N,, and N,,, levels respectively, but increased total dry matter yields. The response of Siratro to cutting frequency was quite different from that reported for white clover. This difference may be of fundamental importance in the management of sub-tropical grass-legume pastures.

The effect of cutting frequency and root segregation on the yield from perennial ryegrass-white clover associations

1967 ◽  
Vol 69 (3) ◽  
pp. 391-397 ◽  
Author(s):  
B. F. Bland
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
The Third ◽  
Nitrogen Yield ◽  
Cutting Frequency ◽  
Nitrogen Yields ◽  
Below Ground ◽  
The Mean ◽  
Defoliation Frequency

1. Dry-matter and nitrogen yields were recorded from perennial ryegrass-white clover associations which were defoliated 2, 4 or 6 times a year during the period 1963 to 1965.2. The average yearly output of dry matter was approximately 4000, 7000 and 6000 lb/acre for 1963, 1964 and 1965 respectively. Nitrogen harvested amounted to 132, 184 and 179 lb N/acre.3. The mean annual dry-matter yields from 2, 4 and 6 defoliations were 5300, 6100 and 6000 lb/acre and the corresponding figures for nitrogen yields were 112, 166 and 217 lb N/acre.4. Both segregation of the species below ground and increasing the defoliation frequency were responsible for higher contributions towards drymatter and nitrogen yield from the clover component.5. A comparison of the nitrogen yields between the plots with species segregated rather than integrated below ground suggests that the effects of underground nitrogen transference from 30–31 lb N/acre could first be demonstrated in the spring of the third year.

The growth and development of a crop of bulrush millet (Pennisetum typhoides S. & H.)

1965 ◽  
Vol 65 (3) ◽  
pp. 341-349 ◽  
Author(s):  
J. E. Begg
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Dry Matter ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Internode Elongation ◽  
Area Index ◽  
Pennisetum Typhoides ◽  
General Flowering ◽  
Cutting Height

The growth and development of a crop of Bulrush millet (Pennisetum typhoides S. & H.) was evaluated by a series of ‘first’ harvests at weekly intervals during the growing season. A final harvest was taken at the end of the season to measure the regrowth.Tillers emerged from the second, until the 5th week after emergence where full light interception was recorded. Then a marked increase in dry-matter production, internode elongation and leaf area index occurred and a peak growth rate of 44 ± 4 g. of dry matter per square metre per day was recorded during the 9th week. General flowering occurred during the 13th week and at 16 weeks the crop yielded 21,735 kg. of dry matter per hectare.Regrowth yields were high following defoliations made at an early vegetative stage when the apical meristem was below the cutting height and then declined as internode elongation raised increasing numbers of apices above the cutting height. Extensive areas of the stand died when defoliated as it approached its period of maximum growth rate.

scholarly journals 528 Modeling of Fruit Set in Apple—Approaches, Model Structure, and Initial Results

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 486B-486
Author(s):  
Alan N. Lakso ◽  
Michael D. White
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Empirical Studies ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Fruit Growth ◽  
Carbon Availability ◽  
Matter Production ◽  
Available Carbon ◽  
Initial Results

Several models of apple tree carbon balance have been developed, including a simplified model by our lab. Tree photosynthesis and total dry matter production is the best characterized except for root growth and root respiration. Once dry matter is produced and partitioned to the different organs (another key problem for modeling), the effects of carbon availability to the fruits on their growth and abscission needs to be modeled. Our approach is based on an observed relationship between increased abscission with decreased fruit growth rate of populations of fruit. From several empirical studies of fruit growth and abscission during chemical thinning or imposed stress early in the season, a relationship was found between % abscission and classes of fruit growth rates. It appears to be best if the fruit growth rate is expressed as a percent of the growth rate of the fastest growing group of fruits in each study. Thus in the model the fruit growth allowed by the available carbon each day is compared to a pre-determined maximum growth rate for the cultivar. The percent-of-maximum growth rate then determines how much abscission will occur. Then the growth rate of the remaining fruit is calculated. Additional parameters of the model allowed for a multiple-day buffer of carbon availability, an imposed fruit number reduction (i.e. equivalent to hand thinning), and temperature effects. Although there are more improvements planned, the initial tests have been promising with the simulations showing realistic patterns of fruit abscission and fruit growth.

Yield and persistence of irrigated lucernes cut at different frequencies, at Tamworth, New South Wales.

1986 ◽  
Vol 26 (2) ◽  
pp. 165 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Dry Matter ◽  
New South ◽  
Total Yield ◽  
Dry Matter Yield ◽  
South Wales ◽  
Cutting Frequency ◽  
Plant Persistence ◽  
Cutting Interval ◽  
The Mean ◽  
The Individual

Three irrigated lucerne cultivars, Pioneer Brand 545 (winter dormant), Condura 73 Brand (semiwinter dormant), and CUF 101 (highly winter active), were harvested at fixed cutting intervals of either 25, 28 ,35, 42 or 48 days from September to April in each of four years. This paper reports the effects of these cutting frequencies on the dry matter yield, leaf to stem ratio and persistence of these cultivars. The effect of cutting frequency on mean total yield (the sum of the mean yields for each harvest) was significant (P<0.05) in each year of the experiment, except year 3. Yields were highest in the 35-day cutting frequency in years 1 and 2. In the fourth year of the experiment the mean total yield of Pioneer Brand 545 and Condura 73 Brand was 29% higher (P<0.05) than CUF 101. By the fourth year substantial amounts of grass were present in the 25- and 28-day cutting interval plots. The contrasts between dormant and active cultivars for the dry matter yield of each of the individual harvests were not consistent in the first two years. In the third and fourth years the active initially outyielded the dormant cultivars at all cutting intervals, but yields of both were generally similar at the end of the season. Increasing the interval between successive harvests generally decreased the mean leaf to stem ratio. The ratio of leaf to stem for CUF 101 was significantly lower (P<0.05) than that for Pioneer Brand 545, with Condura 73 Brand tending to be intermediate. Within cutting intervals, mean declines in plant persistence were similar for cultivars from the different dormancy groups. Largest changes in plant frequency occurred in the fourth year when the mean frequency for the 25- and 28-day plots decreased from 69 to 12% compared with a mean decline from 74 to 65% for the 42- and 48-day cutting intervals. Productive stand life in this experiment was 3 years, even though disease was negligible. Under these conditions grass invasion was mainly related to harvest interval and much less to cultivar dormancy.

scholarly journals Growth rate and haploidization of Aspergillus niger on medium containing p-fluorophenylalanine

1968 ◽  
Vol 12 (3) ◽  
pp. 305-315 ◽  
Author(s):  
Pol Lhoas
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Curves ◽  
Dry Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Complete Medium ◽  
Acid Analogue ◽  
Mean Size ◽  
The Mean

1. The comparison of the dry weight of thin layer haploid and diploid colonies of A. niger on complete medium and complete medium supplemented with p-fluoro-phenylalanine led to the conclusion that there is a difference in growth rates of hyphae under these different conditions.2. The growth curves of the same strains on both media were established. On complete medium, haploids and diploid show a growth rate increasing linearly for about 20 h after germination and reaching a maximum which is then maintained. On p-fluorophenylalanine, the haploids show a similar curve, although the maximum growth rate reached and maintained is about half that on complete medium; for the diploid, however, the maximum is less than the corresponding one in the haploid and, once this maximum has been reached, the growth rate goes down linearly to a very low value which is then maintained.3. The cytological study of the hyphal tip cell showed, in the presence of the amino acid analogue, a reduction of the mean size of the diploid nuclei together with an increase of the number of nuclear fragments. This explains the growth rates observed and is accepted as a confirmation that p-fluorophenylalanine, by its action on the mitosis, favours chromosome losses which lead finally to the production of haploid nuclei.

A note on growth curves of rabbit lines selected on growth rate or litter size

1993 ◽  
Vol 57 (2) ◽  
pp. 332-334 ◽  
Author(s):  
A. Blasco ◽  
E. Gómez
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Growth Curves ◽  
Live Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Standard Errors ◽  
Adult Weight ◽  
Weight Growth ◽  
Using Data

Two synthetic lines of rabbits were used in the experiment. Line V, selected on litter size, and line R, selected on growth rate. Ninety-six animals were randomly collected from 48 litters, taking a male and a female each time. Richards and Gompertz growth curves were fitted. Sexual dimorphism appeared in the line V but not in the R. Values for b and k were similar in all curves. Maximum growth rate took place in weeks 7 to 8. A break due to weaning could be observed in weeks 4 to 5. Although there is a remarkable similarity of the values of all the parameters using data from the first 20 weeks only, the higher standard errors on adult weight would make 30 weeks the preferable time to take data for live-weight growth curves.

Reassessment of Maximum Growth Rates for C3 and C4 Crops

1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growing Season ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Crop Growth ◽  
Close Inspection ◽  
Similar Difference ◽  
Photosynthetic Efficiencies

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.

Interpretation of Experimental Data with Regard to the Activated Sludge Model No.1 and Calibration of the Model for Municipal Wastewater Treatment Plants

1992 ◽  
Vol 25 (6) ◽  
pp. 167-183 ◽  
Author(s):  
H. Siegrist ◽  
M. Tschui
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Municipal Wastewater Treatment ◽  
Activated Sludge Model

The wastewater of the municipal treatment plants Zürich-Werdhölzli (350000 population equivalents), Zürich-Glatt (110000), and Wattwil (20000) have been characterized with regard to the activated sludge model Nr.1 of the IAWPRC task group. Zürich-Glatt and Wattwil are partly nitrifying treatment plants and Zürich-Werdhölzli is fully nitrifying. The mixing characteristics of the aeration tanks at Werdhölzli and Glatt were determined with sodium bromide as a tracer. The experimental data were used to calibrate hydrolysis, heterotrophic growth and nitrification. Problems arising by calibrating hydrolysis of the paniculate material and by measuring oxygen consumption of heterotrophic and nitrifying microorganisms are discussed. For hydrolysis the experimental data indicate first-order kinetics. For nitrification a maximum growth rate of 0.40±0.07 d−1, corresponding to an observed growth rate of 0.26±0.04 d−1 was calculated at 10°C. The half velocity constant found for 12 and 20°C was 2 mg NH4-N/l. The calibrated model was verified with experimental dam of me Zürich-Werdhölzli treatment plant during ammonia shock load.

Dietary Protein Requirements of Fishes — A Reassessment

1987 ◽  
Vol 44 (11) ◽  
pp. 1995-2001 ◽  
Author(s):  
Stephen H. Bowen
Keyword(s):  
Growth Rate ◽  
Dietary Protein ◽  
Protein Concentration ◽  
Trophic Ecology ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Intake Rate ◽  
Protein Requirement ◽  
Fish Physiology ◽  
Protein Retention

It is widely believed that fishes require more dietary protein than other vertebrates. Many aspects of fish physiology, nutrition, and trophic ecology have been interpreted within the context of this high protein requirement. Here, fishes are compared with terrestrial homeotherms in terms of (1) protein requirement for maintenance, (2) relative protein concentration in the diet required for maximum growth rate, (3) protein intake rate required for maximum growth rate, (4) efficiency of protein retention in growth, and (5) weight of growth achieved per weight of protein ingested. The two animal groups compared differ only in relative protein concentration in the diet required for maximum growth rate. This difference is explained in terms of homeotherms' greater requirement for energy and does not reflect absolute differences in protein requirement. The remaining measures of protein requirement suggest that fishes and terrestrial homeotherms are remarkably similar in their use of protein as a nutritional resource. Reinterpretation of the role of protein in fish physiology, nutrition, and trophic ecology is perhaps in order.

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