Temat: leaf area - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Growth analysis using curve fitting method in early and late sown sunflower.
Autorzy:: Parmar, N.G.
Chanda, S.V.
Tematy:: growth analysis
sunflower
relative growth rate
net assimilation rate
leaf area ratio
specific leaf area
leaf weight ratio; Pokaż więcej
Wydawca:: Instytut Hodowli i Aklimatyzacji Roślin
Powiązania:: https://bibliotekanauki.pl/articles/55928726.pdf Link otwiera się w nowym oknie
Opis:: Effect of sowing time on productivity of sunflower was studied. Sunflower seeds were first sown in August (early) and the second sowing was done in September (late). Growth analysis was done at an interval of 5-6 days from germination to maturation. Growth was measured in terms of dry weight and leaf area. Various growth indices like RGR, RLGR, NAR, LAR, LWR, SLA, etc. were calculated. Cubic polynomial was the best fit for all the growth parameters. The dry matter accumulation, leaf area, leaf dry weight and leaf number were significantly more in late grown crop than early grown one. The rate of total dry weight, leaf area and leaf dry weight were higher in late grown crop as compared to early grown one. RGR, RLGR and NAR were higher in the late grown crop from the beginning, which gradually decreased later on, in both the crops. LAR was distinctly more in late grown crop between d 30-40. Changes in SLA were similar to LAR while LWR was more in the beginning and decreased afterwards. RGR showed more correlation with NAR and very low correlation with LAR in both the crops. Thus it is concluded that the late sown crop had better growth, but still, to obtain maximum productivity in sunflower, improvement in RGR and NAR is required.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Growth analysis using curve fitting method in early and late sown sunflower.
Autorzy:: Parmar, N.G.
Chanda, S.V.
Tematy:: growth analysis
sunflower
relative growth rate
net assimilation rate
leaf area ratio
specific leaf area
leaf weight ratio; Pokaż więcej
Wydawca:: Instytut Hodowli i Aklimatyzacji Roślin
Powiązania:: https://bibliotekanauki.pl/articles/2198853.pdf Link otwiera się w nowym oknie
Opis:: Effect of sowing time on productivity of sunflower was studied. Sunflower seeds were first sown in August (early) and the second sowing was done in September (late). Growth analysis was done at an interval of 5-6 days from germination to maturation. Growth was measured in terms of dry weight and leaf area. Various growth indices like RGR, RLGR, NAR, LAR, LWR, SLA, etc. were calculated. Cubic polynomial was the best fit for all the growth parameters. The dry matter accumulation, leaf area, leaf dry weight and leaf number were significantly more in late grown crop than early grown one. The rate of total dry weight, leaf area and leaf dry weight were higher in late grown crop as compared to early grown one. RGR, RLGR and NAR were higher in the late grown crop from the beginning, which gradually decreased later on, in both the crops. LAR was distinctly more in late grown crop between d 30-40. Changes in SLA were similar to LAR while LWR was more in the beginning and decreased afterwards. RGR showed more correlation with NAR and very low correlation with LAR in both the crops. Thus it is concluded that the late sown crop had better growth, but still, to obtain maximum productivity in sunflower, improvement in RGR and NAR is required.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Above- and below-ground tree parameters and their development after modelling of thinning in young elm stands
Autorzy:: Šrámek, Martin
Hurt, Václav
Čermák, Jan
Tematy:: elm
leaf area
absorptive root area
biomass
thinning; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Dendrologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/956995.pdf Link otwiera się w nowym oknie
Opis:: During the last century almost two-thirds of all elms were lost due to the Dutch elm disease. Therefore, elms are an endangered species with a lasting lack of knowledge about ecosystem functions of elms in forest stands. The study describes several above- and below-ground tree parameters and their changes after simulation of thinning in one young forest stand with dominant Ulmus laevis Pall. in the Czech Republic. The distribution of the leaves was measured using the ‘cloud’ technique. The absorptive root area was measured with the aid of the modified earth impedance method to evaluate below-ground tree parameters. Using allometric equations, it was possible to calculate certain tree parameters of individual trees as well as the entire forest stand. The modelling of four thinning intensities (low, medium, high and very high) helped to establish the changes of these tree parameters after treatment. The leaf area index of the stand was 5.6, the absorptive root area index was 1.7 and the total biomass of foliage was 8.5 Mg ha–1 prior to the treatment. The absorptive root area amounted to 30% of the foliage area. The exponential models were developed to predict the above- and below-ground tree parameters. Under the different thinning intensities, the following were found: a negative correlation with the number of trees for the leaf area index, the foliage biomass and the absorptive root area index. This knowledge is important in the process of maintaining the presence of endangered elms in forest stands and in ecosystem services (e.g. carbon storage) throughout Europe.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Leaf area – sapwood area relationship in Scots pine (Pinus sylvestris L.) under mistletoe (Viscum album ssp. austriacum) infection
Autorzy:: Bilgili, E.
Coskuner, K.A.
Ozturk, M.
Tematy:: Leaf area
sapwood area
Scots pine
pine mistletoe; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Dendrologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/2078159.pdf Link otwiera się w nowym oknie
Opis:: Leaf area is linearly correlated with sapwood area in trees. The linearity of this relationship can be affected by some biotic and abiotic factors. Mistletoes are hemi parasitic plants that take up water and mineral nutrients from their hosts and affect host physiological responses. There is no conclusive evidence to show the effect of pine mistletoe (Viscum album ssp. austriacum) on leaf area and sapwood area relationship in Scots pine trees (Pinus sylvestris L.) at tree level. The aim of this study is to determine and quantify the effect of pine mistletoe on the structural variation of leaf area and sapwood area relationship at tree level in Scots pine. A total of 18 mistletoe infected and 12 uninfected Scots pine trees were destructively sampled. All needles and mistletoes were completely removed from sampled trees to determine needle and mistletoe characteristics, biomass and leaf area. Sapwood areas at breast height (BH) and at crown base height (CBH) were determined from wood discs taken from BH (1.3m) and CBH. Sapwood area was delineated by benzidine staining method. Pearson correlation, t-test and regression analyses were conducted to determine the relationship between sapwood area and needle-mistletoe leaf area relationships. The results indicated that both the relationships between sapwood area and leaf area in uninfected, and sapwood area and total leaf area (needle plus mistletoe leaf only) in infected trees were linear. However, the slope of regression equation for mistletoe infected trees was considerably lower when compared to the uninfected trees. As for the variation of the sapwood area along the stem below live crown, there was a slight difference between sapwood area at BH and CBH. The study showed also that mistletoe infection led to a significant reduction in needle size (length, width, area and weight) in Scots pine trees. Significant relationships were found between the sapwood area and leaf area in this study. The results of this study may help fill the gap in the knowledge concerning the impacts of pine mistletoe on the dynamics of Scots pine trees.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Effect of titanium on assimilation leaf area and chlorophyll content of very early-maturing potato cultivars
Wpływ tytanu na powierzchnię asymilacyjną liści i zawartość chlorofilu bardzo wczesnych odmian ziemniaka
Autorzy:: Wadas, Wanda
Kalinowski, Krzysztof
Tematy:: assimilation leaf area
leaf area index (LAI)
leaf greenness index (SPAD)
Tytanit ®
specific leaf area (SLA)
ciężar jednostki powierzchni liści (SLA)
powierzchnia asymilacyjna liści
Tytanit®
wskaźnik pokrycia liściowego (LAI)
wskaźnik zieloności liści (SPAD); Pokaż więcej
Wydawca:: Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydawnictwo PB
Powiązania:: https://bibliotekanauki.pl/articles/2223312.pdf Link otwiera się w nowym oknie
Opis:: Background. Titanium applied via roots or leaves stimulates plant growth. Titanium exerts a favourable effect on plant growth only at low concentration, while at higher concentrations it may exhibit toxic effects. Determining the optimal doses and dates of titanium application are very important in the optimisation of early potato production. Material and methods. The effect of dose (0.2 $dm^3·ha^(-1)$ or 0.4 $dm^3·ha^(-1)$) and date (leaf development stage – BBCH 14-16, tuber formation stage – BBCH 41-43, and at both leaf development stage and tuber formation stage) of a Tytanit ® application (8.5 g Ti in 1 dm3) on the assimilation leaf area and chlorophyll content of very early-maturing potato cultivars was investigated. The field experiment was established as a split-block-split-plot design with a control object without Tytanit®. The assimilation leaf area was measured by the weight method and the chlorophyll content was estimated using a chlorophyll meter SPAD-502. Results. Tytanit ® caused an enlargement of the assimilation leaf area and an increase in chlorophyll content in leaves, particularly under stress conditions. Under thermal and moisture conditions unfavourable for the growth of very early-maturing potato cultivars, a Tytanit ® dose of 0.4 $dm^3·ha^(-1)$ stimulated the growth of leaves more strongly than a dose of 0.2 $dm^3·ha^(-1)$. The plants produced a greater assimilation leaf area when Tytanit ® was only applied once, in the leaf development stage (BBCH 14-16) or in the tuber formation stage (BBCH 41-43). A double Tytanit ® application resulted in a reduction in the assimilation leaf area compared with a single treatment. Following Tytanit ® application, the leaf area index (LAI) averaged 4.13 and was higher by 0.42 compared with the cultivation without growth stimulant, while the specific leaf area (SLA) averaged 3.290 m2·kg-1 and was higher by 0.129 $m^2·kg^(-1)$ than in the cultivation without growth stimulant. The SLA was the highest when Tytanit ® was only applied once in the tuber formation stage (BBCH 41-43). The dose and date of Tytanit® application slightly affected the leaf greenness index (SPAD). Conclusion. The present study demonstrated the stimulating effects of titanium ions (Tytanit®) on the assimilation leaf area and chlorophyll biosynthesis in leaves of very-early maturing potato cultivars under stress conditions.
Tytan podany dokorzeniowo lub dolistnie stymuluje wzrost roślin w sposób specyficzny dla gatunku. Ma korzystny wpływ na wzrost roślin tylko w małym stężeniu, natomiast w wyższych stężeniach może wykazywać działanie toksyczne. Badano wpływ dawki (0,2 $dm^3·ha^(-1)$ i 0,4 $dm^3·ha^(-1)$) i terminu (faza rozwoju liści – BBCH 14-16, faza zawiązywania bulw – BBCH 41-43, faza rozwoju liści i faza zawiązywania bulw) stosowania Tytanitu ® (8,5 g Ti w 1 dm3) na powierzchnię asymilacyjną liści i zawartość chlorofilu bardzo wczesnych odmian ziemniaka. Tytanit ® powodował zwiększenie powierzchni asymilacyjnej liści i zawartości chlorofilu w liściach, szczególnie w warunkach stresowych. W warunkach termicznych i wilgotnościowych, niekorzystnych do wzrostu bardzo wczesnych odmian ziemniaka, dawka Tytanitu ® 0,4 $dm^3·ha^(-1)$ stymulowała wzrost liści bardziej niż 0,2 $dm^3·ha^(-1)$. Powierzchnia asymilacyjna liści była większa, gdy Tytanit ® był stosowany tylko raz, w fazie rozwoju liści (BBCH 14-16) lub w fazie zawiązywania bulw (BBCH 41-43). Po zastosowaniu Tytanitu ® wskaźnik pokrycia liściowego (LAI) wynosił średnio 4,13 i był większy o 0,42 w porównaniu z uprawą bez stymulatora wzrostu, natomiast ciężar jednostki powierzchni liści (SLA) wynosił 3,290 $m^2·kg^(-1)$ i był większy o 0,129 $m^2·kg^(-1)$ niż w uprawie bez stymulatora wzrostu. SLA był największy, gdy Tytanit® był stosowany tylko w fazie zawiązywania bulw (BBCH 41-43). Tytanit ® stymulował biosyntezę chlorofilu w liściach. Dawka i termin stosowania Tytanitu® miały niewielki wpływ na wskaźnik zieloności liści (SPAD).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Metoda oceny wskaźnika powierzchni liści z zastosowanim lotniczego skaningu lidarowego
Method for assessing of leaf area index using lidar data
Autorzy:: Popov, M.
Semko, I.
Kozak, I.
Tematy:: drzewostany sosnowe
powierzchnia lisci
wskaznik powierzchni lisciowej
lotniczy skaning lidarowy
regresja wielokrotna
pine stand
leaf area
leaf area index
multiple regression; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/35944.pdf Link otwiera się w nowym oknie
Opis:: Zaproponowana została metoda zdalnej oceny LAI z zastosowaniem materiałów lotniczego skaningu lidarowego. Obliczeniowa część metody opiera się na modelu regresji pomiędzy wartościami wskaźnika LAI i danymi lotniczego skaningu lidarowego. Opracowane zostały równania regresji wielokrotnej. Przedstawione zostały wyniki testowania proponowanej metody, które potwierdzają jej wydajność i wysoką dokładność. Przedstawiony został przegląd nowoczesnych metod oceny wskaźnika powierzchni liści (LAI) – jednego z najbardziej kompleksowych i obiektywnych wskaźników produkcyjnej aktywności roślinności. Krótko opisano naziemne metody oceny LAI oraz ich oprzyrządowanie. Zauważono, że główną i niewątpliwą zaletą naziemnej metody oceny LAI jest wiarygodność uzyskanych wyników. Przy konieczności oceny poziomu aktywności roślinności na dużych obszarach i przy ograniczonych zasobach czasowych, zastosowanie technik naziemnych napotyka poważne trudności. W takich przypadkach bardziej obiecującym okazuje się podejście związane z zastosowaniem zdalnych technik i technologii. Pokazano kierunki ewentualnych dalszych kroków do zwiększenia dokładności metody.
A remote sensing method for assessing LAI index using airborne lidar data is proposed. A calculation body of the proposed method is based on regression model which couples LAI value and lidar data derivatives. Multiple regression equation is constructed. The results of experi-mental investigation confirm the effectiveness and high accuracy of the proposed method. The paper presents a review of the contemporary approaches to the assessment of leaf area index (LAI) as one of most comprehensive and objective indicators of photosynthesis processes activity of vegetation. Methods for LAI in-situ assessing, its procedures and instrumental support are described in brief. It is emphasized that the main and absolute advantage of in-situ methods is the reliability of calculated LAI estimates. However, the application of in-situ methods is connected with significant problems when it is necessary to assess photosynthesis processes activity level for vegetation in cases of vast areas with time limitations. As the authors observe, for similar cases is more promising to use remote sensing techniques and technologies. Directions for further research to improve the precision of the method are outlined therewith.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Using Vegetative Indices to Quantify Agricultural Crop Characteristics
Autorzy:: Kokhan, Svitlana
Vostokov, Anatoliy
Tematy:: vegetation indice
aboveground biomass
leaf area index
leaf nitrogen concentration; Pokaż więcej
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:: https://bibliotekanauki.pl/articles/123155.pdf Link otwiera się w nowym oknie
Opis:: In this study, the winter wheat aboveground biomass (AGB), leaf area index (LAI) and leaf nitrogen concentration (LNC) were estimated using the vegetation indices, derived from a high spatial resolution Pleiades imagery. The AGB, LAI and LNC estimation equations were established between the selected VIs, such as NDVI, EVI and SAVI. Regression models (linear and exponential) were examined to determine the best empirical regression equations for estimating the crop characteristics. The results showed that all three vegetation indices provide the AGB, LAI and LNC estimations. The application of NDVI showed the smallest value of RMSE for the aboveground biomass estimation at stem elongation and heading of winter wheat. EVI gave the best significant estimation of LNC and showed better results to quantify winter wheat vegetation characteristics at stem elongation phase. This study demonstrated that Pleiades high spatial resolution imagery provides in-situ crop monitoring.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Reed canopy transparency under different levels of diffuse radiation
Przezroczystość trzcinowiska w różnych warunkach rozproszenia promieniowania słonecznego
Autorzy:: Harenda, K.
Piatyszek, M.
Chojnicki, B.H.
Tematy:: diffuse radiation
solar radiation
reed
leaf area index
ecosystem
canopy; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/36026.pdf Link otwiera się w nowym oknie
Opis:: Diffused solar radiation increases ecosystem productivity. One of the explanations for this phenomenon is the fact that this type of radiation penetrates the vegetation layer more efficiently, thus changing radiation conditions under the plant canopy. The study of reed transparency under different radiation diffusion conditions makes it possible to estimate the amount of radiation energy that reaches plants living under the reed canopy. The presented radiation parameters were obtained using the SS1 probe (Delta-T Devices Ltd. UK.). The measurements were carried out in September 2014 in a reed canopy in the Rzecin peatland (52°45′N, 16°18′E, 54 m a.s.l.). Analyses showed that the transparency of the reed canopy (Tr) is directly proportional to the degree of diffusion (D*) of the radiation which reaches the plant surface and the reed Tr value is always greater at cloudy conditions than during periods of low radiation diffusion. At the same time, Tr is inversely proportional to the leaf area index (LAI). Under high diffusion of radiation the plants growing under the reed canopy gain approximately 38% radiation energy in comparison with periods characterised by low values of D*.
Rozproszone promieniowanie słoneczne powoduje wzrost produktywności ekosystemów. Jest to spowodowane między innymi tym, że ten rodzaj promieniowania lepiej penetruje roślinność, zmieniając tym samym warunki radiacyjne pod okapem roślin. Badanie przezroczystości trzcinowiska w różnych warunkach rozpraszania promieniowania pozwala na określenie warunków (ilości docierającej energii promienistej) bytowania roślin żyjących pod okapem trzcin. Prezentowane dane są wynikiem pomiarów wykonanych za pomocą sondy SS1 firmy Detla-T służącej do oceny warunków oraz parametrów radiacyjnych roślin. Badania przeprowadzono we wrześniu 2014 r. w łanie trzcin na torfowisku w Rzecinie (52°45′N, 16°18′E, 54 m n.p.m.). W wyniku przeprowadzonych analiz stwierdzono, iż przezroczystość trzcinowiska (Tr) jest wprost proporcjonalna do stopnia rozproszenia promieniowania docierającego do powierzchni roślin (D*), a jej wartość jest zawsze większa w warunkach D* = 1.0 od wartości Tr w okresach o małym rozpraszaniu promieniowania. Jednocześnie Tr jest odwrotnie proporcjonalne do wartości współczynnika ulistnienia (LAI). W warunkach pełnego rozproszenia ilość energii promienistej docierającej do roślin znajdujących się pod okapem trzcin wzrasta średnio o ok. 38% w porównaniu do okresów o niskich wartościach D*.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Spatial mapping of the leaf area index using remote sensing and ground measurements – the Biebrza National Park case study
Autorzy:: Ignar, Stefan
Szporak-Wasilewska, Sylwia
Gregorczyk, Małgorzata
Tematy:: leaf area index
wetlands
remote sensing
spectral vegetation indices
Biebrza; Pokaż więcej
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Powiązania:: https://bibliotekanauki.pl/articles/36062944.pdf Link otwiera się w nowym oknie
Opis:: The purpose of the described research was an attempt to estimate the leaf area index (LAI) parameter describing the structure of the vegetation based on the Landsat 5TM satellite imagery and field measurements made with the use of an optical plant canopy analyzer. The study was carried out in north-eastern Poland in the Biebrza river valley within the boundaries of the Biebrza National Park during the growing season of the year 2007. There were 13 spectral indices given in the literature known to be correlated with the LAI. The highest coefficient of determination and the highest correlation coefficient were obtained for the normalized difference vegetation index (NDVI) and the soil adjusted vegetation index (SAVI) indices for the wetland areas in the Biebrza river valley. The field measurements of the leaf area index and its spatial representation on satellite image show that the vegetation of natural river valleys is characterized by high spatial and seasonal variability. The study of the LAI on such large natural areas that are extensively used also requires knowledge of the methods of land use and the application of individual agrotechnical measures.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Acclimation of acacia hybrid (Acacia mangium x Acacia auriculiformis) vegetative propagules to soil water deficits
Autorzy:: Alamgir, Kabir M
Rafiqul Hoque, A.T.M.
Kamaluddin, M.
Tematy:: acacia
acacia hybrid
Acacia mangium x Acacia auriculiformis
acclimation
soil water deficit
rooted cutting
biomass
leaf area
specific leaf area
water deficit
soil moisture
Bangladesh; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Dendrologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/41229.pdf Link otwiera się w nowym oknie
Opis:: The aim of the present work was to investigate the acclimation potential of acacia hybrid (Acacia mangium Willd×Acacia auriculiformis A.Cunn.ex Benth)vegetative propagules to soil water stress in the nursery of Institute of Forestry and Environmental Sciences, Chittagong University. Acacia hybrid showed significant decrease in total plant biomass in two months water-stressed conditions. Allocation of assimilates to root growth relative to shoot found to be an important acclimation mechanism. Leaf area ratio (LAR)increased under water-stressed plants with simultaneous increase in specific leaf area (SLA)but almost no change in leaf weight ratio (LWR). Significant increase in LAR with limited water supply by increasing SLA was likely to be an important acclimation potential since this relative increase in leaf area compensated, at least partially, for a lower photosynthesis under water-stressed conditions aswas evident from decreased mean total biomass under water-stressed regimes.
Dostawca treści:: Biblioteka Nauki

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