scholarly journals LEAVES AREA AND PHOTOSYNTHETIC PIGMENTS OF DOMINANT PLANTS OF RURAL PASTURES IN THE STEPPE BELT OF MOUNT ARAGATS IN ARMENIA

2020 ◽  
pp. 57-64
Author(s):  
Т.А. Саргсян ◽  
М.А. Навасардян ◽  
Б.Х. Межунц
Keyword(s):  
Medicago Sativa ◽  
Leaf Area ◽  
Photosynthetic Pigments ◽  
Individual Species ◽  
Hordeum Bulbosum ◽  
Artemisia Absinthium ◽  
Aegilops Cylindrica ◽  
Tanacetum Vulgare ◽  
Steppe Belt ◽  
Agropyron Repens

В статье обобщены результаты исследований ассимиляционной поверхности и содержания фотосинтетических пигментов в листьях растений основных луговых групп юго-западного склона горы Арагац (1300-1900 м н.у.м.). Данные территории находятся под сильным воздействием экологических и антропогенных факторов, отличаются низкой продуктивностью, следовательно, нуждаются в коренном улучшении. В рамках настоящей работы была поставлена задача создать базу экспериментальных данных по биологическим параметрам, ответственным за формирование урожая. Объектами исследований были следующие виды злаковых – Коленница (Aegilops cylindrica), Костер (Bromus tectorium), Мятлик (Poa bulbosa), Пырей (Agropyron repens), Ячмень (Hordeum bulbosum), бобовых – Эспарцет (Onobrychis radiata), Клевер (Trifolium pratense), Вика (Vicia variabilis), Люцерна (Medicago sativa) и разнотравных растений – Молочай (Euphorbia virgata), Пижма (Tanacetum vulgare), Скабиоза (Scabiosa bipinnata), Котовник (Nepeta Мussini), Тысячелистник (Achillea millefolium), Полынь (Artemisia absinthium). Площадь листьев определялась весовым методом, экстракция пигментов проводилась с помощью диметилсульфоксида, а измерение их содержания – на спектрофотометре СФ-16. Выявлен широкий диапазон колебаний площади листьев у индивидуальных видов (0,9-11,5), тогда как разница между луговыми группами была незначительной (4,0-5,9 дм2/растение). Сумма пигментов в листьях разнотравных растений на 22 % была меньше, чем у злаковых и бобовых, а соотношение хлорофиллов А и Б колебалось в пределах 1,8-3,5. Таким образом, на исследуемых кормовых угодьях максимальные размеры площади листьев обнаружены у многолетних злаковых, сумма пигментов и хлорофилл А – бобовых, а хлорофилл Б – разнотравных растений. The article summarizes the scientific results on the assimilation surface and the content of photosynthetic pigments in the leaves of plants in the main meadow groups of the southwestern slope of Mount Aragats (1300-1900 m above sea level). Under the strong influence of environmental and anthropogenic factors these territories are characterized by low productivity, therefore, they need efficient improvement. Within the framework of this scientific article, the task was set to create a database of experimental data on biological parameters responsible for the yield farming. The objects of the current research were the following types of cereals – Goatgrass (Aegilops cylindrica), Cheat grass (Bromus tectorium), Bluegrass (Poa bulbosa), Wheatgrass (Agropyron repens), Barley (Hordeum bulbosum), legumes – Sainfoins (Onobrychis radiata), Clover (Trifolium pratenium), Cow vetch (Vicia variabilis), Alfalfa (Medicago sativa), and herbs – Leafy spurge (Euphorbia virgata), Tansy (Tanacetum vulgare), Scabiosa (Scabiosa bipinnata), Catnip (Nepeta Mussini), Yarrow (Achillea milleteminium), Wormwood (Artemisia absinthium). The leaf area was determined by the gravimetric method, pigment extraction was carried out using dimethyl sulfoxide, and their content was measured on an SF-16 spectrophotometer. A wide range of fluctuations in the leaf area in individual species was revealed (0.9-11.5), while the difference between meadow groups was insignificant (4.0-5.9 dm2/plant). The amount of pigments in the leaves of herbs was 22% less than that in cereals and legumes, and the ratio of chlorophylls A and B varied within 1.8-3.5. Thus, on the studied foraging grounds, the maximum leaf area was found in perennial cereals, the sum of pigments and chlorophyll A – in legumes, and chlorophyll B – in herbs. leaves area, photosynthetic pigments, wild plants, natural pastures, steppe belt

scholarly journals Interactive Effects of Nitrogen and Sulfur Nutrition on Growth, Development, and Physiology of Brassica carinata A. Braun and Brassica napus L.

2021 ◽  
Vol 13 (13) ◽  
pp. 7355
Author(s):  
Shivendra Kumar ◽  
Ramdeo Seepaul ◽  
Ian M. Small ◽  
Sheeja George ◽  
George Kelly O’Brien ◽  
...  
Keyword(s):  
Electron Transport ◽  
Leaf Area ◽  
Photosynthetic Pigments ◽  
Net Photosynthesis ◽  
Brassica Carinata ◽  
Internode Length ◽  
Erucic Acid Content ◽  
Total Biomass ◽  
Node Number ◽  
S 100

Brassica carinata (carinata) has emerged as a potential biofuel source due to its high erucic acid content, making it desirable for various industrial applications. Nitrogen (N) and sulfur (S) are required as primary sources of nutrition for growth and development in different oilseed crops and their utilization is interdependent. The purpose of the study was to analyze the interactive effect of N and S nutrition on the growth and other physiological activities of carinata and B. napus (napus). Four treatments, i.e., optimum NS (+N+S, 100% N and 100% S); N limited (−N+S, 0% N, 100% S); S limited (+N−S, 100% N, 0% S), and NS limited (−N−S, 0% N and 0% S) of N and S in full-strength Hoagland solution were imposed in the current study. Effect of different NS treatments was observed on vegetative traits such as number of primary and secondary branches, total leaf area, total biomass production and allocation, and physiological traits such as production of photosynthetic pigments, net photosynthesis, electron transport, and other aspects for both carinata and napus. The traits of stem elongation, number of nodes, node addition rate, internode length, number of primary and secondary branches were 60%, 36%, 50%, 35%, 56%, and 83% lower, respectively, in napus in comparison to carinata. Different NS treatments also positively influenced the production of photosynthetic pigments such as chlorophyll (Chl) a and b and carotenoids in carinata and napus. The concentration of Chla was 11% higher in napus in comparison to carinata. The rate of net photosynthesis, electron transport, and fluorescence was 12%, 8%, and 5% higher based on overall value, respectively, in napus compared to carinata. On the other hand, the overall value for stomatal conductance decreased by 5% in napus when compared to carinata. Different growth-related traits such as vegetative (plant height, node number, internode length, leaf area, number of primary and secondary branches), reproductive (pod number, pod length, seeds per pod), and photosynthetic capacity in oilseed brassicas are correlated with the final seed and oil yield and chemical composition which are of economic importance for the adoption of the crop. Thus, the analysis of these traits will help to determine the effect of NS interaction on crop productivity of carinata and napus.

Characterizing the light environment in Sierra Nevada mixed-conifer forests using a spatially explicit light model

2004 ◽  
Vol 34 (6) ◽  
pp. 1332-1342 ◽  
Author(s):  
Rolf Gersonde ◽  
John J Battles ◽  
Kevin L O'Hara
Keyword(s):  
Leaf Area ◽  
Sierra Nevada ◽  
Forest Type ◽  
Individual Species ◽  
Spatially Explicit ◽  
Conifer Forests ◽  
Prediction Equations ◽  
Mixed Conifer ◽  
Sapwood Area ◽  
Mixed Conifer Forests

The spatially explicit light model tRAYci was calibrated to conditions in multi-aged Sierra Nevada mixed-conifer forests. To reflect conditions that are important to growth and regeneration of this forest type, we sampled a variety of managed mature stands with multiple canopy layers and cohorts. Calibration of the light model included determining leaf area density for individual species with the use of leaf area – sapwood area prediction equations. Prediction equations differed between species and could be improved using site index. The light model predicted point measurements from hemispherical photographs well over a range of 27%–63% light. Simplifying the crown representation in the tRAYci model to average values for species and canopy strata resulted in little reduction in model performance and makes the model more useful to applications with lower sampling intensity. Vertical light profiles in managed mixed-conifer stands could be divided into homogeneous, sigmiodal, and continuous gradients, depending on stand structure and foliage distribution. Concentration of leaf area in the upper canopy concentrates light resources on dominant trees in continuous canopies. Irregular canopies of multiaged stands, however, provide more light resources to mid-size trees and could support growth of shade-intolerant species. Knowledge of the vertical distribution of light intensity in connection with stand structural information can guide regulation of irregular stand structures to meet forest management objectives.

Comparison of Fall-Applied Pronamide with Spring-Applied Sethoxydim for Quackgrass (Agropyron repens) Control in Established Alfalfa (Medicago sativa)

Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Gilles D. Leroux ◽  
Robert G. Harvey
Keyword(s):  
Chemical Composition ◽  
Medicago Sativa ◽  
Crude Protein ◽  
Total Yield ◽  
Late Spring ◽  
Neutral Detergent Fiber ◽  
Acid Detergent Fiber ◽  
Herbicide Treatments ◽  
Agropyron Repens

Established stands of alfalfa (Medicago sativaL.) at two field locations were treated at one date in the fall with pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynil) benzamide] at 0.8 and 1.6 kg ai/ha and at two dates in the spring with sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} at 0.3 and 0.6 kg ai/ha for the control of quackgrass [Agropyron repens(L.) Beauv. # AGRRE]. Herbicide efficacy was compared by measuring botanical and chemical composition and yield of forage. Both chemicals suppressed quackgrass in first-cutting herbage. While sethoxydim at the higher rate was equivalent to pronamide for increasing the proportion of alfalfa in forage, pronamide was superior for increasing seasonal total yield. Late postemergence applications of sethoxydim were more effective for quackgrass regrowth control than earlier spring applications. Controlling quackgrass in late spring resulted in lower crude protein (CP) content in first-cutting forage than did controlling it in fall. Alfalfa competing with untreated quackgrass had a lower CP content than where quackgrass was controlled with herbicides. All herbicide treatments reduced the neutral-detergent fiber (NDF) of the herbage. As measured by the acid-detergent fiber (ADF) concentration of alfalfa, sethoxydim slightly retarded spring growth of the legume.

The leaf area of an Australian heathland with reference to seasonal changes and the contribution of individual species

1968 ◽  
Vol 16 (3) ◽  
pp. 579 ◽  
Author(s):  
R Jones
Keyword(s):  
Leaf Area ◽  
Seasonal Changes ◽  
Individual Species ◽  
Seasonal Growth ◽  
Seasonal Fluctuations ◽  
Total Leaf Area ◽  
Area Index ◽  
Total Community ◽  
Community Area ◽  
Community Growth

The leaf area of an Australian heathland was determined on harvested material for a series of monthly harvests over 2 years. The leaf area index (LAI) varied from 1 .8 to 3.2. Seasonal growth flushes accounted for the high values, while leaf fall induced by water stress restored the equilibrium to approximately 2.0. The dominant shrub, Leptospermum myrsinoides, contributed 53.5% of the total leaf area, and this species alone caused the seasonal fluctuations in community area. Only three other species contributed more than 5 % to the total. Community growth was characterized by the behaviour of L. myrsinoides. Detailed analyses of this species showed the need for seasonal measurements to fully describe the LAI of evergreen communities.

Effects of Frost and Maturity on Glyphosate Phytotoxicity, Uptake, and Translocation

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 110-114 ◽  
Author(s):  
H. E. Davis ◽  
R. S. Fawcett ◽  
R. G. Harvey
Keyword(s):  
Medicago Sativa ◽  
Controlled Environment ◽  
Plant Maturity ◽  
Agropyron Repens

The effect of temperatures below 0 C and plant maturity on the phytotoxicity of glyphosate [N-(phosphonomethyl)glycine] on rapidly growing alfalfa (Medicago sativaL. ‘Vernal’) and quackgrass [Agropyron repens(L.) Beauv.] plants was studied in a controlled environment. Pretreatment at −4 C partially protected alfalfa from injury by 0.8 kg/ha of glyphosate at six alfalfa maturities. This same treatment had no significant effect on glyphosate phytotoxicity to quackgrass. Pretreatment at −4 C increased translocation of glyphosate in quackgrass but reduced its translocation in alfalfa. A greater reduction in translocation occurred in the smaller alfalfa plants.

scholarly journals Composition of phytoplankton in the Puck Bay and the open Baltic Sea

2017 ◽  
Author(s):  
Klaudia Świacka ◽  
Alicja Michnowska ◽  
Jakub Maculewicz ◽  
Izabela Przednowek ◽  
Iga Ogrodowczyk ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Photosynthetic Pigments ◽  
Outer Part ◽  
Individual Species ◽  
Hydrodynamic Conditions ◽  
Phytoplankton Composition ◽  
Puck Bay

The Puck Bay is an area characterised by specific hydrodynamic conditions that determine the distribution and composition of phytoplankton. The aim of this study was to investigate the differences in the phytoplankton composition and the content of photosynthetic pigments between the Puck Bay and open Baltic Sea. The material was collected from four stands which were localised in the inner and outer part of Hel Peninsula. In this study, it has been demonstrated that the composition of individual species of phytoplankton differed between stands in the inner and outer part of the Puck Bay. This investigation has also shown that the number of phytoplankton taxa was similar in three stands and it was much lower on the last stand (Stand 4). The differences in the concentration of photosynthetic pigments between all stands have also been observed.

scholarly journals Biologically Active Compounds and Antioxidant Activity of the Plants from CSBG SB RAS Collection of the Asteraceae Family

2021 ◽  
Vol 38 ◽  
pp. 00055
Author(s):  
Elena Khramova ◽  
Tatyana Kukushkina ◽  
Tatyana Shaldaeva ◽  
Yuliya Pshenichkina
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Achillea Millefolium ◽  
Artemisia Absinthium ◽  
Tanacetum Vulgare ◽  
Active Compounds ◽  
Artemisia Dracunculus ◽  
Pectin Substances

The article presents Data on the content of biologically active compounds (BAC) and the total phenolic antioxidants activity (TPA) evaluated for leaves and inflorescences of Achillea millefolium, Anthemis tinctoria, Artemisia absinthium, A. dracunculus, Leucanthemum vulgare, Pyrethrum balsamita, P. macrophyllum, Tanacetum vulgare. The leaves and inflorescences of the plants contain flavonols, catechins, tannins, carotenoids, pectin substances. High content of phenolic compounds was found in Artemisia dracunculus and Achillea millefolium (352.34 – 398.99 mg/g of DW). The highest level of catechins was registered in inflorescences (8.01 mg/g) and leaves (4.58 mg/g) of Artemisia absinthium. The content of pectin substances in the studied plants was quite high, with the biggest share of protopectins (50.6 – 95.9 mg/g). The maximum quantity of pectins was found in the leaves and inflorescences of Leucanthemum vulgare (11.2-12.7 mg/g), protopectins – in the leaves of Tanacetum vulgare (95.9 mg/g). The highest content of carotenoids was found in the leaves of plants, except for Leucanthemum vulgare. The highest antioxidant activity was recorded for water-ethanol extracts from leaves of Achillea millefolium (up to 1.09 mg/g) and inflorescences of Artemisia dracunculus (0.94 mg/g) plants due to the increased content of phenolic compounds, in particular flavonols and tannins, compared to the other species.

Influence of Quackgrass (Agropyron repens) Density and Duration of Interference on Soybeans (Glycine max)

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 614-619 ◽  
Author(s):  
Frank L. Young ◽  
Donald L. Wyse ◽  
Robert J. Jones
Keyword(s):  
Glycine Max ◽  
Leaf Area ◽  
Dry Weight ◽  
Assimilation Rate ◽  
Soybean Yield ◽  
Soybean Leaf ◽  
Net Assimilation ◽  
Density Study ◽  
Number Of Branches ◽  
Agropyron Repens

The effect of quackgrass [Agropyron repens(L.) Beauv.] density and duration of interference on soybeans [Glycine max(L.) Merr.] was investigated in two studies. In the density study, the average reduction in soybean yield by quackgrass densities of 520 and 910 shoots/m2was 19 and 55%, respectively. Quackgrass densities of 95 and 160 shoots/m2did not significantly reduce soybean yields. The number of branches that produced pods, the number of pods and seeds per plant, and soybean height were reduced by the two highest densities. In 1980, quackgrass densities of 265 and 595 shoots/m2reduced soybean leaf area and plant dry weight. Leaf area partitioning (LAP), leaf weight partitioning (LWP), and net assimilation rate (NAR) of soybeans were reduced by a quackgrass density of 595 shoots/m2. In the duration study, interference by a natural stand of quackgrass for 6 weeks, 8 weeks, and full-season decreased soybean yield an average of 11, 23, and 33%, respectively. Results from the duration study suggest that a selective postemergence herbicide for the control of quackgrass in soybeans would be beneficial if available.

Control of Quackgrass with Pyriclor

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 439-441 ◽  
Author(s):  
K. P. Buchholtz
Keyword(s):  
Zea Mays ◽  
Medicago Sativa ◽  
Avena Sativa ◽  
Agropyron Repens

Quackgrass (Agropyron repens (L.) Beauv.) was controlled with applications 1 to 8 months prior to plowing and planting of from 1 to 4 lb/A 2,3,5-trichloro-4-pyridinol (pyriclor). Corn (Zea mays L., hybrid W530) planted on pyriclor-treated plots grew normally and yielded as well as on plots given the standard preplow treatment of 2 lb/A of 2-chloro-4-ethylamino-6-isopropylamino-5-triazine (atrazine). Oats (Avena sativa L., var. Portage) was injured by soil residues of pyriclor from 2-lb/A applications made 20 months previously. Alfalfa (Medicago sativa L., var. Vernal) was somewhat more tolerant of pyriclor than was oats.

Sign in / Sign up

Export Citation Format

Share Document