Effect of species, plant part, and season of harvest on n-alkane concentrations in the cuticular wax of common rangeland grasses from southern Africa

2001 ◽  
Vol 52 (9) ◽  
pp. 875 ◽  
Author(s):  
D. G. Smith ◽  
R. W. Mayes ◽  
J. G. Raats
Keyword(s):  
Southern Africa ◽  
Diet Composition ◽  
Common Species ◽  
Flower Head ◽  
Grass Species ◽  
Wet Season ◽  
Reliable Technique ◽  
Plant Parts ◽  
Plant Samples ◽  
Whole Plant

The use of plant alkane concentrations to measure diet composition of herbivores has been shown to be a reliable technique in animals grazing temperate, sown pastures that contain a relatively small number of plant species. There is potential to develop this technique for use with free-range animals foraging upon species-rich rangeland. In order for the technique to be effective, the alkane concentration patterns (ACP) of the component species of the diet must be distinct from one another. Common species of grasses from southern Africa were analysed for their alkane concentrations in order to evaluate the use of the alkane technique for measuring diet composition under complex rangeland conditions. The alkane profiles were determined in different plant parts from 40 grass species gathered during the wet season and 23 gathered during the dry season. Statistical analysis, using ANOVA, showed that there were highly significant differences (P < 0.001) in the C 25, C 27 , C 29 C 31 , C 33 , and C 35 alkane concentrations between flower head and stem during both the dry and wet seasons. Similar statistical differences were apparent in the C 25 , C 27 , C 29 , and C 31 alkane concentrations of leaf and stem during both seasons; differences in C 33 and C 35 concentrations were significant but at a lower level (P < 0.01 and P < 0.05, respectively). Differences in C 25 , C 27 , and C 29 alkane concentrations between flower head and leaf were only significant (P < 0.001) during the wet season. Statistical differences (P < 0.001) between whole plant samples obtained in different seasons were due to changes in the proportion of flower head, leaf, and stem. Cluster analysis often showed less similarity between plant parts of the same species than between whole plant samples of different species. It was concluded that ACPs measured in the selected species were probably too similar and thus, plants could not be identified using the alkane technique. However, it was possible to use the alkane technique to determine the proportions of flower-head, leaf, and stem in the diet.

N-alkane profiles of common rangeland species in northern China and the influence of drying method on their concentrations

2008 ◽  
Vol 88 (1) ◽  
pp. 137-141 ◽  
Author(s):  
Bin Shu ◽  
Lijun Lin ◽  
Yingjun Zhang ◽  
Hai Wang ◽  
Hailing Luo
Keyword(s):  
Key Words ◽  
Diet Composition ◽  
Northern China ◽  
Common Species ◽  
Drying Methods ◽  
Drying Method ◽  
Plant Parts ◽  
Internal Markers ◽  
Steppe Grassland ◽  
Plant Wax

Plant wax alkanes have been used as internal markers to estimate diet composition of grazing animals. However, alkane contents in samples may vary depending on the drying method used. This study was undertaken to determine the alkane profiles and concentrations of 17 common range land species in northern China with two different drying methods. The results showed that regardless of drying methods, the odd-chain alkanes, particular C29 and C33, predominated in cuticular wax in all 17 common species and their component plant parts. The alkane patterns of plant species within the same genus were relatively similar and the differences in alkanes between stem and leaf were generally smaller than those between inflorescences and leaf or stem. The influence of drying methods on alkane concentrations varied depending on family and individual alkane. The effect of drying methods on C29 seemed to be smaller than other alkanes in all the samples. The oven-dry method produced higher concentrations (P < 0.05) in the three major alkanes (C23, C31 and C33) in the Gramineae family than the freeze-dry method. Therefore, studies dealing with alkane concentrations should use the same drying method for all samples. Key words: Alkane pattern, steppe grassland, oven-dry, freeze-dry

Effect of phosphorus on three perennial Stylosanthes species in tropical Australia. II. Phosphorus and nitrogen within the plant and implications for grazing animals

1989 ◽  
Vol 40 (6) ◽  
pp. 1205 ◽  
Author(s):  
MA Gilbert ◽  
DG Edwards ◽  
KA Shaw ◽  
RK Jones
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
Soil P ◽  
Plant Parts ◽  
Whole Plant ◽  
Nitrogen Concentrations ◽  
Tropical Australia ◽  
Whole Plants ◽  
Phosphorus Application ◽  
Green Stem

This paper describes the effect of phosphorus application on concentrations and distribution of phosphorus (P) and nitrogen (N) in three Stylosanthm specics (S. scabra cv. Scca, S. guiunensis cv. Schofield and S. viscosa CPI 34904) grown in the field on a soil of low acid-extractable (0.005 M H2SO4) P status (4 mg/kg). Over a two-year period (May 1978 to September 1979), regular measurements were made of P and N in whole plant shoots, leaves, stems, inflorescence, seed and litter.Phosphorus application increased P concentrations in all three legumes, but did not affect its pattern of seasonal change throughout the year. The P (and N) concentrations in most plant parts decreased through the wet season to reach minima in the late dry season. However, with seed there was little seasonal variation. In the second year, Seca was more efficient at taking up P and utilizing it for growth under low soil P conditions than Schofield. CPI 34904 was less efficient than Seca at taking up P, but also used P efficiently for growth. The efficient utilization of P in the leaves and stems of Seca and CPI 34904 meant that P levels were often below the level (0.12%) considered adequate for growth of grazing cattle. Dry season P concentrations in all legumes were inadequate. When P was applied, P concentrations in leaf and green stem of all species were higher than 0.12% during the wet season, but green stem of Seca and CPI 34904 fell below this level during the dry season.Applied P slightly increased N concentrations in leaves, green stems and whole plants of all species. Nitrogen concentrations were adequate (> 1.1% N) for maintenance of cattle weight at most times. Only in the late dry season did green stem of Seca contain insufficient N.Phosphorus application had little effect on the distribution of P and N within the plants. All species held a large percentage (20-50%) of these nutrients in green stems, but CPI 34904 was exceptional in directing up to 60% of the P and N to inflorescence and seed at the expense of leaf and stem.

scholarly journals Delayed Senescence in Soybean: Terminology, Research Update, and Survey Results from Growers

2016 ◽  
Vol 17 (2) ◽  
pp. 76-83 ◽  
Author(s):  
C. J. Harbach ◽  
T. W. Allen ◽  
C. R. Bowen ◽  
J. A. Davis ◽  
C. B. Hill ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Biotic Factors ◽  
Delayed Senescence ◽  
Plant Parts ◽  
Whole Plant ◽  
Research Findings ◽  
Survey Results ◽  
Soybean Plants ◽  
Grower Survey ◽  
Specific Symptoms

The terms used to describe symptoms of delayed senescence in soybean often are used inconsistently or interchangeably and do not adequately distinguish the observed symptoms in the field. Various causes have been proposed to explain the development of delayed senescence symptoms. In this article, we review published reports on delayed senescence symptoms in soybean, summarize current research findings, provide examples of terms related to specific symptoms, and present an overview of the results of a multi-state survey directed to soybean growers to understand their concerns about delayed soybean senescence. Some of these terms, such as green bean syndrome and green stem syndrome, describe symptoms induced by biotic factors, while other terms describe symptoms associated with abiotic factors. Some delayed senescence terms involve the whole plant remaining green while other terms include just the stem and other plant parts such as pods. In the grower survey, 77% reported observing soybean plants or plant parts that remained green after most plants in the field were fully mature with ripe seed. Most respondents attributed these symptoms to changes in breeding and choice of cultivars. At the end of this article, we standardized the terms used to describe delayed senescence in soybean. Accepted for publication 23 March 2016. Published 15 April 2016.

The efficacy of seasonal terrestrial water storage forecasts for predicting vegetation activity over Africa

2021 ◽  
Author(s):  
Benjamin I Cook ◽  
Kimberly Slinski ◽  
Christa Peters-Lidard ◽  
Amy McNally ◽  
Kristi Arsenault ◽  
...  
Keyword(s):  
Regression Model ◽  
Southern Africa ◽  
Water Storage ◽  
Dry Season ◽  
Forecast Skill ◽  
Terrestrial Water Storage ◽  
Wet Season ◽  
Area Index ◽  
Vegetation Activity ◽  
Terrestrial Water

AbstractTerrestrial water storage (TWS) provides important information on terrestrial hydroclimate and may have value for seasonal forecasting because of its strong persistence. We use the NASA Hydrological Forecast and Analysis System (NHyFAS) to investigate TWS forecast skill over Africa and assess its value for predicting vegetation activity from satellite estimates of leaf area index (LAI). Forecast skill is high over East and Southern Africa, extending up to 3–6 months in some cases, with more modest skill over West Africa. Highest skill generally occurs during the dry season or beginning of the wet season when TWS anomalies from the previous wet season are most likely to carry forward in time. In East Africa, this occurs prior to and during the transition into the spring “Long Rains” from January–March, while in Southern Africa this period of highest skill starts at the beginning of the dry season in April and extends through to the start of the wet season in October. TWS is highly and positively correlated with LAI, and a logistic regression model shows high cross-validation skill in predicting above or below normal LAI using TWS. Combining the LAI regression model with the NHyFAS forecasts, 1-month lead LAI predictions have high accuracy over East and Southern Africa, with reduced but significant skill at 3-month leads over smaller sub-regions. This highlights the potential value of TWS as an additional source of information for seasonal forecasts over Africa, with direct applications to some of the most vulnerable agricultural regions on the continent.

scholarly journals Production of cabbage grown in pots containing legumes' root and shoot

Revista CERES ◽  
2012 ◽  
Vol 59 (5) ◽  
pp. 689-694 ◽  
Author(s):  
Thiago de Oliveira Vargas ◽  
Ellen Rúbia Diniz ◽  
Ricardo Henrique Silva Santos ◽  
Alysson Roberto de Almeida ◽  
Segundo Urquiaga ◽  
...  
Keyword(s):  
Block Design ◽  
Mineral Fertilizer ◽  
Dry Weight ◽  
N Fertilization ◽  
Recommended Dose ◽  
Legume Species ◽  
Mineral Fertilization ◽  
Mineral N ◽  
Plant Parts ◽  
Whole Plant

Roots effect is not generally considered in studies assessing the performance of crops in response to green manuring. However, such effect can contribute to a better understanding of crop rotation. The aim of this study was to assess the effect of root and shoot of two legumes on the production of cabbage. The experiment was conducted in pots of 10 liters containing substrate of 2:1 soil/sand. The experiment was arranged in a factorial scheme (2x3 + 2) in a randomized block design with five replicates using two legume species (Crotalaria juncea L. and Canavalia ensiformis L), three plant parts (root, shoot, or whole plant), and two additional treatments (mineral fertilization with 100% and 50% of the recommended dose of N for growing cabbage). Pots with legume treatments received mineral fertilizer with 50% of the recommended dose of N for growing cabbage. The experimental plot consisted of a pot containing one plant of cabbage. Legumes were grown in pots and harvested at 78 days. The root biomass was determined in extra pots. Production was assessed using head fresh and dry weight. The application of the whole plant of both legume species reduced cabbage production. However, root or shoot of both legume species was equivalent to 50% of mineral N fertilization required for the cultivation of cabbage.

scholarly journals Phytotoxic Activity of Parthenium Against Wheat and Canola Differ With Plant Parts and Bioassays Techniques

2016 ◽  
Vol 34 (1) ◽  
pp. 11-24 ◽  
Author(s):  
A. KHALIQ ◽  
F ASLAM ◽  
A MATLOOB ◽  
A JAVAID ◽  
A TANVEER ◽  
...  
Keyword(s):  
Seedling Growth ◽  
Filter Paper ◽  
Leaf Extracts ◽  
Invasive Weed ◽  
Test Species ◽  
Chlorophyll Contents ◽  
Phenolic Contents ◽  
Plant Parts ◽  
Phytotoxic Activity ◽  
Whole Plant

Phytotoxic effects of invasive weed Parthenium hysterophorus were studied by using whole plant, leaf and root aqueous extracts at 0, 2.5, 5.0, 7.5 and 10% (w/v) concentrations against germination and early seedling growth of wheat and canola. Studies were carried out both in Petri plates with filter paper as substratum placed in controlled conditions and soil-filled plastic pots placed in open environments. Pronounced variation was noted for phytotoxic activity of different plant parts of parthenium, aqueous extract concentrations, test species, and bioassay techniques. Aqueous parthenium extracts either inhibited or delayed the germination and suppressed seedling growth of test species over control. For both test species, all the germination attributes were suppressed to a greater extent in Petri plates than in plastic pots. Leaf extracts were more suppressive to germination of test species than whole plant and root extracts. Increasing extract concentration beyond 2.5% caused significant reduction in seedling dry biomass of both test species. Aqueous parthenium extract diminished chlorophyll contents of wheat and canola by 32-63% and 29 69%, respectively. Nevertheless, an increase of 9-172% and 22-60% in phenolic contents of wheat and canola was recorded. Canola appeared to be more susceptible than wheat at all extract concentrations. Present study concluded that bioassays conducted under controlled condition using filter paper as substratum may be misleading due to over estimation of allelopathic response and variation in potential of receiver and donor species. Furthermore, it implies that threshold concentrations of allelochemicals for test species in Petri plates are rarely reached under field conditions.

scholarly journals Later Wet Seasons with More Intense Rainfall over Africa under Future Climate Change

2018 ◽  
Vol 31 (23) ◽  
pp. 9719-9738 ◽  
Author(s):  
Caroline M. Dunning ◽  
Emily Black ◽  
Richard P. Allan
Keyword(s):  
Southern Africa ◽  
Crop Yields ◽  
Central Africa ◽  
Cmip5 Models ◽  
Future Climate Change ◽  
Boreal Summer ◽  
Wet Season ◽  
Socioeconomic Impacts ◽  
Continental Scale ◽  
Rainfall Frequency

Changes in the seasonality of precipitation over Africa have high potential for detrimental socioeconomic impacts due to high societal dependence upon seasonal rainfall. Here, for the first time we conduct a continental-scale analysis of changes in wet season characteristics under the RCP4.5 and RCP8.5 climate projection scenarios across an ensemble of CMIP5 models using an objective methodology to determine the onset and cessation of the wet season. A delay in the wet season over West Africa and the Sahel of over 5–10 days on average, and later onset of the wet season over southern Africa, is identified and associated with increasing strength of the Saharan heat low in late boreal summer and a northward shift in the position of the tropical rain belt over August–December. Over the Horn of Africa rainfall during the “short rains” season is projected to increase by over 100 mm on average by the end of the twenty-first century under the RCP8.5 scenario. Average rainfall per rainy day is projected to increase, while the number of rainy days in the wet season declines in regions of stable or declining rainfall (western and southern Africa) and remains constant in central Africa, where rainfall is projected to increase. Adaptation strategies should account for shorter wet seasons, increasing rainfall intensity, and decreasing rainfall frequency, which will have implications for crop yields and surface water supplies.

scholarly journals Medicinal plants used by tribal and rural community of Sata Pokhran area of tehsil Pampore of district Pulwama, Jammu and Kashmir-India

2018 ◽  
Vol 7 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Mohd Shahijahan Dar ◽  
◽  
GH. Nabi Joo ◽  
Showkat Ahmad Ganaie ◽  
◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Plant Species ◽  
Rural Community ◽  
Jammu And Kashmir ◽  
Medicinal Uses ◽  
Mode Of Administration ◽  
Plant Parts ◽  
Family Names ◽  
Whole Plant

Man has used plants since time immemorial to alleviate sufferings and ailments. The present study attempts to explore and document the medicinal plants used against several diseases by the tribal and rural community of Sata Pokhran area of district Pulwama. During the survey from March to September 2017, a total of 28 different plant species belonging to equal number of genera and 16 different families were found to be used as effective remedies. The present study revealed that either whole plant or some plant parts are used to cure different diseases. It was also observed that majority of plant species are used to treat more than one disease and likewise more than one plant species is used to treat a particular disease. The scientific, local and family names of these medicinal plants along with their parts used, mode of administration and ethno medicinal uses are presented in this paper

scholarly journals Digestibility of plant fractions from different genotypes and the predictability of quality of forage maize in northwest Europe.

1985 ◽  
Vol 33 (1) ◽  
pp. 56-59
Author(s):  
P.C. Struik
Keyword(s):  
Genetic Factors ◽  
Forage Maize ◽  
Maize Hybrids ◽  
Plant Parts ◽  
Physical Chemical ◽  
Whole Plant ◽  
Northwest Europe ◽  
Total Plant

Differences in digestibility of plant parts from 5 forage maize hybrids are described and related to the differences in whole plant digestibility of crops grown under different conditions. Plant parts differed greatly in digestibility, and the proportions of the DM of the total plant were variable due to numerous physical, chemical, biological and genetic factors. Whole-plant digestibility, however, was fairly constant and predictable. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Allelopathic effects of invasive alien species Parthenium hysterophorus L. on seed germination of paddy and wheat

2018 ◽  
Vol 6 ◽  
pp. 1-5
Author(s):  
Binita Shrestha ◽  
Chandra Bahadur Thapa
Keyword(s):  
Seed Germination ◽  
Parthenium Hysterophorus ◽  
Cereal Crops ◽  
Wheat Roots ◽  
Plant Parts ◽  
Randomized Design ◽  
Whole Plant ◽  
Maximum Inhibition ◽  
Allelopathic Effects ◽  
Stem Leaf

The invasive species are the major cause of crop loss, across the globe, mainly due to their allelopathic effects on the growth of crop plants. In this study, we explored the allelopathic effects of Parthenium hysterophorus on germination of two major cereal crops of Nepal, Rice (Oryza sativa) and Wheat (Triticum aestivum). The experiment was conducted at laboratory of Department of Botany, Prithivi Narayan Campus, Pokhara, Nepal during 2017. In laboratory, seeds of rice and wheat were treated with aqueous extracts of P. hysterophorus plant parts viz. root, stem, leaf, inflorescence and whole plant with concentration of 5, 10, 15 and 20%. The experiment was laid out in a complete randomized design (CRD) in a factorial arrangement with three replicates of each test. The result suggests that the effect was more on wheat than on rice. The maximum inhibition in seed germination of rice was recorded by the inflorescence extract however, in wheat seed germination was inhibited by leaf extract. In both rice and wheat, roots were highly affected than shoots because root first encounters the toxic allelochemicals and absorbs it. The highest concentration (20%) of leaf, inflorescence and whole plant extract was found to be most pernicious whereas root and stem were recorded to have little effects.

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