Effect of previous cutting interval and of leaf area remaining after cutting on regrowth of Macroptilium atropurpureum cv. Siratro

1974 ◽  
Vol 14 (68) ◽  
pp. 343 ◽  
Author(s):  
RJ Jones
Keyword(s):  
Leaf Area ◽  
Practical Implication ◽  
Soluble Sugars ◽  
Ground Level ◽  
Fold Increase ◽  
Water Soluble ◽  
Hot Water ◽  
Lag Phase ◽  
Area Index ◽  
Plant Yield

Experiments with Siratro were conducted at Samford, south east Queensland to study the effects of previous cutting and defoliation treatments on regrowth. In the first experiment, swards of Siratro were cut at 7.5 cm above ground level every 4 weeks, every 8 weeks or cut once at 16 weeks during spring and summer. Regrowth of all treatments over ten weeks was measured after varying (by leaf removal) the stubble leaf area index (LAI) of the plots cut every four weeks. Pattern of regrowth yield was similar for all treatments with a pronounced lag phase after cutting. Regrowth yield after 10 weeks differed between treatments and was linearly related (P < 0.01 ) to residual LAI in the stubble at the start of regrowth. In the absence of stubble leaves, plots previously cut at 16 weeks or at 8 weeks yielded marginally more than those cut every 4 weeks. There were no marked treatment differences in gross root morphology other than a two fold increase in stolon rooting for the 16-week treatment. Nitrogen content of the roots (mean 1.38 per cent) was unaffected by treatment, but the per cent hot water soluble sugars were lower for the 16 week defoliation treatment than for the 8-week and the 4-week treatments. In the second experiment individual plants were cut to a uniform stubble every 4 weeks and either 0, 5, or 10 leaves were left. Dry weight of regrowth and stolon development were greatest when most leaves were left. Two thirds of the plants died after six cuttings with complete defoliation but none died when either 5 or 10 leaves were retained. Plant survival was not related to plant yield or degree of stoloniferous development. However, there was a strong correlation between stolon number and plant yield under this intensive cutting regime. The practical implication of the results in the management of Siratro is discussed.

Effects of defoliation management on the productivity of an irrigated Persian clover sward

1994 ◽  
Vol 34 (2) ◽  
pp. 205 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Ground Level ◽  
Maximum Growth ◽  
Fungal Disease ◽  
Area Index ◽  
Herbage Yield ◽  
Defoliation Treatment ◽  
Negative Effect ◽  
Persian Clover

A field experiment investigated the effects of frequency and height of defoliation on the productivity of an irrigated Persian clover (Trifolium resupinatum) sward. Combinations of 4 intervals of harvest (3, 6, 9, 12 weeks) and 2 heights of defoliation (to ground level or 5 cm above ground level) were used in a randomised block experiment, with 2 additional treatments of 4 and 18 weeks between harvests defoliated to ground level. Total herbage accumulation ranged from 8.46 to 13.90 t DM/ha and varied according to defoliation management. Except for the very short defoliation intervals, harvesting to 5 cm was less productive than harvesting to ground level. The effects of leaf area index, herbage yield, and infection with leaf fungal disease on growth rates were assessed. Leaf area had a positive effect, and fungal disease a negative effect, on herbage growth rates, while maximum growth rates in autumn-winter were achieved when herbage yield reached about 2.0 t DM/ha. Dead matter accumulation increased with the interval between harvests, and weeds invaded the plots at both the shortest and longest defoliation intervals. The quality of seed produced (seed weight) was not influenced by defoliation treatment (0.1112 g/100 seeds, on average). Defoliation interval was positively related to number of inflorescences and quantity of seed set, but height of defoliation did not significantly affect these variables. It was concluded that the optimum interval of harvest was 6-9 weeks. Height of defoliation had only minor effects, due to the small difference in residual dry matter between the treatments.

Response of red chilli (Capsicum annuum L.) to fertigation and mulching

2017 ◽  
Vol 2 (02) ◽  
pp. 169-173
Author(s):  
G. Chandramohan Reddy ◽  
S. S. Hebbar
Keyword(s):  
Leaf Area ◽  
Capsicum Annuum ◽  
Growth Parameters ◽  
Fruit Yield ◽  
Water Soluble ◽  
Growth And Yield ◽  
Index Number ◽  
Area Index ◽  
Capsicum Annuum L ◽  
Dry Fruit

Experiments were conducted to evaluate the performance of red chilli (Capsicum annuum L.) during 2015-16 at the Division of vegetable crops, Indian Institute of Horticulture Research, Hessaraghatta, Bangalore to determine the effect of different fertigation sources and mulching on growth parameters, yield and fertilizer use efficiency (FUE). Fertigation was done both water soluble fertilizers and normal fertilizers with different doses. The results revealed that significantly higher growth and yield parameters viz., plant height (cm), number of branches per plant, leaf area and leaf area index, number of fruits per plant, length of the fruit (cm), girth of the fruit (cm), fruit weight (g) dry fruit yield per plant (g), dry fruit yield per hectare (t) were observed by the treatments viz., application of water soluble fertilizers 100 per cent (Recommended dose of fertilizers) RDF using urea, 19:19:19 and KNO3 through fertigation with mulching, followed by Normal fertilizers 100 per cent RDF using Urea, DAP, MOP through fertigation with mulching. From this investigation it is concluded that water soluble fertilizers as well as normal fertilizers fertigation with mulching ideal for maximum growth and yield of the chilli crop.

Predicting the effects of hardwood competition on red pine seedling growth

1992 ◽  
Vol 22 (10) ◽  
pp. 1510-1515 ◽  
Author(s):  
Alan S. White ◽  
Katherine J. Elliott
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Negative Impact ◽  
Ground Level ◽  
Red Pine ◽  
Area Index ◽  
Clear Cut ◽  
Site Characteristics ◽  
Early Effects ◽  
Highly Correlated

Pin cherry (Prunuspensylvanica L.f.) and striped maple (Acerpensylvanicum L.) are potentially important competitors of red pine (Pinusresinosa Ait.) planted on recently clear-cut hardwood sites. By experimentally manipulating initial competitor densities on 2.0-m2 plots, we were able to quantify and compare the effects of competitor species on red pine seedlings 2 years after planting on two sites in western Maine. Various measures of competitor biomass and leaf area index (LAI) were highly correlated; thus, we used LAI to quantify competitor abundance. On the site with poorer growth for both competitors and red pine, the only red pine variable significantly correlated with competitor LAI was specific leaf area (SLA) of current needles. On the site with better growth for all species, various measures of red pine biomass as well as diameter at ground level and SLA were significantly correlated with competitor LAI. Seedling height was not significantly correlated with competitor LAI at either site. Although there were no significant differences between competitor species in terms of their effect per unit of LAI, pin cherry tended to achieve much higher LAI (and biomass) than did striped maple and thus had a greater negative impact on red pine seedling growth. We conclude that general predictions of the early effects of competition under field conditions are possible, but that the strength of the relationships may be influenced by the extent to which microsite factors and site characteristics are incorporated.

scholarly journals In Vitro Evaluation of Cocoa Pod Husk Pectin as a Carrier for Chronodelivery of Hydrocortisone Intended for Adrenal Insufficiency

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Ofosua Adi-Dako ◽  
Kwabena Ofori-Kwakye ◽  
Mariam El Boakye-Gyasi ◽  
Samuel Oppong Bekoe ◽  
Samuel Okyem
Keyword(s):  
Drug Release ◽  
Adrenal Insufficiency ◽  
Aqueous Medium ◽  
Water Soluble ◽  
Hot Water ◽  
Matrix Tablets ◽  
Lag Phase ◽  
Wet Granulation ◽  
Cocoa Pod Husk

This study evaluated the in vitro potential of cocoa pod husk (CPH) pectin as a carrier for chronodelivery of hydrocortisone intended for adrenal insufficiency. FTIR studies found no drug-CPH pectin interactions, and chemometric analysis showed that pure hydrocortisone bears closer similarity to hydrocortisone in hot water soluble pectin (HWSP) than hydrocortisone in citric acid soluble pectin (CASP). CPH pectin-based hydrocortisone matrix tablets (~300 mg) were prepared by direct compression and wet granulation techniques, and the tablet cores were film-coated with a 15% HPMC formulation for timed release, followed by a 12.5% Eudragit® S100 formulation for acid resistance. In vitro drug release studies of the uncoated and coated matrix tablets in simulated gastrointestinal conditions showed that wet granulation tablets exhibit greater retardation of drug release in aqueous medium than directly compressed tablets. CASP showed greater suppression of drug release in aqueous medium than HWSP. Wet granulation HWSP-based matrix tablets coated to a final coat weight gain of ~25% w/w were optimized for chronodelivery of hydrocortisone in the colon. The optimized tablets exhibited a lag phase of ~6 h followed by accelerated drug release in the colonic region and have potential to control night time cortisol levels in patients with adrenal insufficiency.

Growth analysis of poppies (Papaver somniferum L.)

1982 ◽  
Vol 33 (2) ◽  
pp. 233 ◽  
Author(s):  
B Chung
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Growth Analysis ◽  
Crop Growth ◽  
Maximum Difference ◽  
Area Index ◽  
Crop Growth Rate ◽  
Plant Yield ◽  
Total Plant

A growth analysis study of the effects of two contrasting environments on the yield of field grown poppies (Papaver somnifevum L.) was undertaken using regression techniques. The change in total plant yield during the 1977-78 season was found to be adequately fitted by a cubic polynomial equation. In contrast, the change in total plant yield during the 1976-77 season and the development of leaf area index in both seasons were found to be adequately fitted by quartic polynomial equations. The total plant yield in the 1977-78 season was considerably higher than that in the 1976-77 season from the beginning of December to dry maturity with a maximum difference of 2 200 kg/ha on 15 January. This yield difference can be attributed to the higher crop growth rate in the 1977-78 season from 30 November to 18 January with a maximum difference of 12 g/m2/day on 30 December. Leaf area index was considered to be more important than net assimilation rate in influencing the crop growth rate up to 20 December. The differences in leaf area between the two seasons could be attributed to the climatic conditions. Under Tasmanian conditions, poppy yields could be expected to be reasonably stable from year to year, provided that the crop is encouraged to grow at its optimum during the whole season.

scholarly journals Particle Retention Capacity, Efficiency, and Mechanism of Selected Plant Species: Implications for Urban Planting for Improving Urban Air Quality

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2109
Author(s):  
Huixia Wang ◽  
Hui Shi
Keyword(s):  
Leaf Area ◽  
Plant Species ◽  
Water Soluble ◽  
Eriobotrya Japonica ◽  
Urban Greening ◽  
Retention Capacity ◽  
Retention Efficiency ◽  
Individual Tree ◽  
Area Index ◽  
Green Area

Atmospheric particulate matter (PM) has been of concern owing to its negative effects on human health and its role in environmental degradation. For mitigation purposes, it is important to select the most efficient plant species in urban greening. Here, a fast, cost-saving methodology was first added to the conventional method to investigate the size-resolved PM retention capacity and efficiency of twenty plant species. Surface PM (SPM), which can be removed by water and brushing, accounted for 44.9%−66.9% of total PM, in which the water-soluble PM (DPM) accounted for 12.9%−22.1% of total PM. A large mass proportion of in-wax PM (14.1%−31.7%) was also observed. Platycladus orientalis, Eriobotrya japonica, Viburnum odoratissimum, Magnolia grandiflora had the highest AEleaf (retention efficiency on per unit leaf area) to retain SPM within different diameter classes (DPM, PM0.1-2.5, PM2.5-10, PM>10). AEplant (retention efficiency of individual tree) varied greatly among different plant species, mainly due to the dependence on the total area of a tree. AEland (retention efficiency on per unit green area) is a suitable index for PM retention ability and efficiency. In general, P. orientalis, V. odoratissimum, Pittosporum tobira, Photinia serrulate, M. grandiflora, E. japonica were the efficient species in retaining PM at different scales (i.e., leaf, individual tree, green area). The species like Trifolium repens, Phyllostachys viridis, were the least efficient plant species. The investigated species are all evergreen species, which will remove PM throughout the whole year, even in winter. So, we recommended that the plant species with the highest PM retention efficiency can be used in urban greening. Meanwhile, horticulture practices should also be considered to improve the leaf area index to improve their PM retention and air purification abilities.

scholarly journals Genetic Analysis and Trait Association in Multi-parent Advanced Generation Inter-Cross (MAGIC) F2 Population of Tobacco (Nicotiana tabacum L.)

2017 ◽  
Vol 9 (3) ◽  
pp. 392-396
Author(s):  
Chakravarthi V.N. DHAVALA ◽  
Uma Mahesh PAPIDANDLA ◽  
Chidanand ULLAGADDI ◽  
Ganesh C. THIMMEGOWDA ◽  
Saiprasad V.S. GANDRA
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Soluble Sugars ◽  
Stem Diameter ◽  
Total Soluble Sugars ◽  
Area Index ◽  
F2 Population ◽  
Leaf Yield ◽  
Grade Index ◽  
Advanced Generation

Genetic variability studies offers basic information related to genetic properties of the population based on which breeding methods could be formulated for further improvement of the crop. The estimates of heritability, coefficients of variability and genetic advance was calculated in a multi-parent advanced generation inter-cross (MAGIC) F2 segregating populations for 10 traits including nicotine percentage, total soluble sugars and yield contributing traits during 2015 seasons at Northern Light Soils (NLS). The estimates of phenotypic coefficients of variation (PCV) were high and moderate for plant height (18.16%), number of leaves (15.96%), leaf area index (27.35%), internodal length (21.01%), stem diameter (16.73%), grade index (13.86%), nicotine percentage (19.87%), total soluble sugars (39.81%), chlorides (23.35%) and leaf yield (13.27%) in MAGIC-F2 segregating populations at NLS 2015 season. High heritability coupled with high and moderate genetic advance was observed for all the traits studied. Correlation studies revealed that total soluble sugars was positively and significantly correlated with leaf area index, stem diameter, grade index and leaf yield. However total soluble sugars was negatively correlated with nicotine as total nicotine alkaloid and with chlorides percentage. Path coefficient analysis revealed that total percentage of sugars could be improved through selection of grade index, stem diameter, leaf area index and cured leaf yield which were positively correlated with total soluble sugar percentage. The current study also revealed that the MAGIC F2 population could be used for development high sugar lines with moderate or low levels of nicotine and chlorides in tobacco.

scholarly journals Predicting the denitrification capacity of sandy aquifers from shorter-term incubation experiments and sediment properties

2013 ◽  
Vol 10 (2) ◽  
pp. 1013-1035 ◽  
Author(s):  
W. Eschenbach ◽  
R. Well
Keyword(s):  
Organic Carbon ◽  
Water Soluble ◽  
Hot Water ◽  
15N Tracer ◽  
Lag Phase ◽  
Aquifer Material ◽  
Abstract Knowledge ◽  
Pleistocene Aquifers ◽  
One Year ◽  
Sandy Aquifers

Abstract. Knowledge about the spatial variability of denitrification rates and the lifetime of denitrification in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, regression models were derived to estimate the measured cumulative denitrification of aquifer sediments after one year of incubation from initial denitrification rates and several sediment parameters, namely total sulphur, total organic carbon, extractable sulphate, extractable dissolved organic carbon, hot water soluble organic carbon and potassium permanganate labile organic carbon. For this purpose, we incubated aquifer material from two sandy Pleistocene aquifers in Northern Germany under anaerobic conditions in the laboratory using the 15N tracer technique. The measured amount of denitrification ranged from 0.19 to 56.2 mg N kg−1 yr−1. The laboratory incubations exhibited high differences between non-sulphidic and sulphidic aquifer material in both aquifers with respect to all investigated sediment parameters. Denitrification rates and the estimated lifetime of denitrification were higher in the sulphidic samples. For these samples, the cumulative denitrification measured during one year of incubation (Dcum(365)) exhibited distinct linear regressions with the stock of reduced compounds in the investigated aquifer samples. Dcum(365) was predictable from sediment variables within a range of uncertainty of 0.5 to 2 (calculated Dcum(365)/measured Dcum(365)) for aquifer material with a Dcum(365) > 20 mg N kg−1 yr−1. Predictions were poor for samples with lower Dcum(365), such as samples from the NO3− bearing groundwater zone, which includes the non-sulphidic samples, from the upper part of both aquifers where denitrification is not sufficient to protect groundwater from anthropogenic NO3− input. Calculation of Dcum(365) from initial denitrification rates was only successful for samples from the NO3−-bearing zone, whereas a lag-phase of denitrification in samples from deeper zones of NO3− free groundwater caused imprecise predictions. In our study, Dcum(365) of two sandy Pleistocene aquifers was predictable using a combination of short-term incubations and analysis of sediment parameters. Moreover, the protective lifetime of denitrification sufficient to remove NO3− from groundwater in the investigated aquifers is limited, which demonstrates the need to minimise anthropogenic NO3− input.

Agronomic evaluation of a tiller inhibition gene (tin) in wheat. II. Growth and partitioning of assimilate

2005 ◽  
Vol 56 (2) ◽  
pp. 179 ◽  
Author(s):  
B. L. Duggan ◽  
R. A. Richards ◽  
A. F. van Herwaarden
Keyword(s):  
Leaf Area ◽  
Wheat Plant ◽  
Dry Weight ◽  
Light Interception ◽  
Kernel Weight ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Area Index ◽  
Terminal Drought ◽  
Eastern Australia

Wheats with reduced tillering have been proposed for areas regularly subject to a terminal drought. A wheat plant with a genetic disposition to produce fewer stems is now possible through the introgression of a gene that inhibits tillering (tin). This study was conducted to determine the effect of the tin gene on the dynamics of tillering, light interception, and dry-matter production and partitioning in several different cultivars of wheat. Commercial cultivars and their near-isogenic pairs differing in the presence of the tin gene were grown in well-watered tubes and also in the field in south-eastern Australia where terminal drought is common. Tiller number, light interception, leaf area index (LAI), biomass, and the partitioning of biomass were recorded at various intervals throughout the growing season. Water-soluble carbohydrate (WSC) levels in the stems of field-grown plants were also determined in some environments at anthesis and maturity. In tubes and in field environments, lines with the tin gene produced tillers at the same rate as their free tillering counterparts but ceased tillering sooner. Under conditions where the free tillering lines produced over 1000 shoots/m2, lines containing the tin gene produced 600 shoots/m2. However, by maturity, fertile spike numbers were 350 and 450/m2 for lines with and without the tin gene, respectively. Despite the large difference in tillering, there were only small differences in LAI, light interception throughout the season, and biomass. There were small differences in the proportional allocation of biomass, and the tin lines partitioned more of their biomass towards spikes at anthesis and stored more WSC in stems. Dry weight distribution varied with genetic background, but in general the tin gene increased leaf area ratio and root to shoot ratio but decreased specific leaf area. It is concluded that the tin gene may be advantageous under terminal drought. This would come from the reduced light interception prior to anthesis and thereby potential for greater transpiration during grain filling as well as a greater capacity for stem carbohydrate storage and remobilisation. These factors are consistent with a greater harvest index and kernel weight associated with lines containing the tin gene.

scholarly journals Predicting long-term denitrification capacity of sandy aquifers from incubation experiments and sediment properties

2012 ◽  
Vol 9 (7) ◽  
pp. 8807-8858 ◽  
Author(s):  
W. Eschenbach ◽  
R. Well
Keyword(s):  
Organic Carbon ◽  
Water Soluble ◽  
Hot Water ◽  
15N Tracer ◽  
Lag Phase ◽  
Aquifer Material ◽  
Abstract Knowledge ◽  
Pleistocene Aquifers ◽  
Sandy Aquifers

Abstract. Knowledge about the spatial variability of denitrification rates and the lifetime of denitrification in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, regression models were derived to estimate the measured denitrification capacity of incubated aquifer sediments from initial denitrification rates and several sediment parameters, namely total sulphur, total organic carbon, extractable sulfate, extractable dissolved organic carbon, hot water soluble organic carbon and potassium permanganate labile organic carbon. For this purpose, we incubated aquifer material from two sandy Pleistocene aquifers in Northern Germany under anaerobic conditions in the laboratory using the 15N tracer technique. The measured long-term denitrification capacities ranged from 0.18 to 56.2 mg N kg−1 yr−1. The laboratory incubations exhibited high differences between non-sulphidic and sulphidic aquifer material in both aquifers with respect to all investigated sediment parameters. Denitrification rates and the estimated lifetime of denitrification were higher in the sulphidic samples. Denitrification capacity measured during one year of incubation (Dcap) was predictable from sediment variables within a range of uncertainty of 0.5 to 2 (calculated Dcap/measured Dcap) for aquifer material with a Dcap > 20 mg N kg−1 yr−1. Predictions were poor for samples with lower Dcap like samples from the NO3−-bearing groundwater zone, which includes the non-sulphidic samples, from the upper part of both aquifers where Dcap is not sufficient to protect groundwater from anthropogenic NO3− input. Calculation of Dcap from initial denitrification rates was only successful for samples from the NO3−-bearing zone, whereas a lag-phase of denitrification in samples from deeper zones of NO3− free groundwater caused imprecise predictions. Our results thus show that Dcap of sandy Pleistocene aquifers can be predicted using a combination of short-term incubation and analysis of sediment parameters. Moreover, the protective lifetime of denitrification sufficient to remove NO3− from groundwater in the investigated aquifers is limited which demonstrates the need to minimize anthropogenic NO3− input.

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