scholarly journals Growth and chlorophyll indices in seedlings of Calotropis procera (Aiton) W. T. Aiton submitted to different levels of shading

2019 ◽  
Vol 13 ◽  
pp. 164
Author(s):  
Francisco Romário Andrade Figueiredo ◽  
João Everthon Da Silva Ribeiro ◽  
Ester Dos Santos Coêlho ◽  
Jackson Silva Nóbrega ◽  
Manoel Bandeira De Albuquerque
Keyword(s):  
Leaf Area ◽  
Chlorophyll A ◽  
Specific Leaf Area ◽  
Polynomial Regression ◽  
Abiotic Factors ◽  
Specific Weight ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Calotropis Procera ◽  
Area Index

Several abiotic factors may influence the growth and development of forest species. Among these, luminosity is one of the most important, because it affects plant physiological processes and control their metabolism. The objective of this study was to evaluate the effect of different shading levels under growth and chlorophyll indices on Calotropis procera plants. The experiment was conducted in a greenhouse in a completely randomized design with 5 treatments (0, 30, 50, 70 and 90% of shading), 8 replicates and one plant per plot. Growth characteristics (leaf area, leaf area index, specific leaf area, leaf area ratio and leaf specific weight) and chlorophyll a, b, total index and chlorophyll a/b ratio were evaluated. The data were submitted to analysis of variance by the F test and in the cases of significance a linear and polynomial regression analysis was performed. Shade levels in the 40% range provide higher leaf area and leaf area index in silk flower plants. The specific leaf area and the leaf area ratio are positively influenced by shading. In shaded environments silk flower plants have reduced chlorophyll indices.

scholarly journals GROWTH AND SEED YIELD OF SUNFLOWER ON SOIL FERTILIZED WITH CASSAVA WASTEWATER

2017 ◽  
Vol 30 (4) ◽  
pp. 963-970 ◽  
Author(s):  
MARA SUYANE MARQUES DANTAS ◽  
MARIO MONTEIRO ROLIM ◽  
ELVIRA MARIA REGIS PEDROSA ◽  
MANASSÉS MESQUITA DA SILVA ◽  
DANIEL DA COSTA DANTAS
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Seed Yield ◽  
Specific Leaf Area ◽  
Weight Ratio ◽  
Dry Mass ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Area Index ◽  
Cassava Wastewater

ABSTRACT Cassava wastewater is the liquid residue of the cassava flour processing and its application to the soil as fertilizer for agricultural crops is a good alternative to sources of nutrients for plants. In this context, the objective of this work was to evaluate the growth and seed yield of sunflower on soil fertilized with cassava wastewater. A randomized block experimental design with four replications was used, with six cassava wastewater rates (0, 8.5, 17, 34, 68 and 136 m3 ha-1) and six plant sampling times (15, 30, 45, 60, 75 and 90 days after sowing), using the sunflower cultivar Helio-250. The evaluated variables were total leaf area, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, shoot dry mass and sunflower seed yield. The use of cassava wastewater rate of 136 m3 ha-1 increases the seed yield, leaf area, leaf area index and shoot dry mass, and results in lower leaf area ratio, specific leaf area and leaf weight ratio of sunflower (cv. Helio-250) crops.

scholarly journals DIFFERENT SHADING NETS IN ESCAROLE GROWTH

2017 ◽  
Vol 26 (4) ◽  
pp. 584-595
Author(s):  
Daniela Meira ◽  
Daniele Cristina Fontana ◽  
Carla Janaina Werner ◽  
Thais Pollon Zanatta ◽  
Patricia Brezolin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Block Design ◽  
Weight Ratio ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Biological Productivity ◽  
Area Index ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of work was to verify the effect of different shading levels in escarole crop, during summer in the northwest of Rio Grande do Sul. The experiment was conducted at the Federal University of Santa Maria, Frederico Westphalen RS Campus, in 2015 with Escarola Lisa escarole cultivar. The experimental design was a randomized complete block design with three shading levels (0%, 30%, 50%), with six replications. Growth evaluation were performed in destructive manner every seven days, from transplant to harvest point. From the information obtained, traits were determined: leaf area, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, biological productivity, absolute growth rate, relative growth rate, net assimilation rate. The data obtained were analyzed by the statistical program Genes, the Tukey test at 5% of error probability. The shading level 30% provided greater leaf area, higher biological productivity and absolute growth rate. However, the leaf area ratio was higher when shading level 50% was tested. However, it can be said that the shading levels favor growth of escarole crop.

scholarly journals The performance of perennial ryegrass in binary mixtures with lucerne and red clover under N fertilization

2017 ◽  
Vol 33 (3) ◽  
pp. 349-360
Author(s):  
Zorica Bijelic ◽  
Violeta Mandic ◽  
Vesna Krnjaja ◽  
Dragana Ruzic-Muslic ◽  
Aleksandar Simic ◽  
...  
Keyword(s):  
Leaf Area ◽  
Perennial Ryegrass ◽  
Specific Leaf Area ◽  
Red Clover ◽  
N Fertilization ◽  
Area Ratio ◽  
Grass Species ◽  
Seeding Rate ◽  
Area Index ◽  
Different Levels

Perennial ryegrass is a very important and widespread grass species used for livestock nutrition, in particularly ruminants. As a species that is most commonly used on grasslands, it is grown in mixtures with other types of grasses and legumes. The objective of the research was to investigate the performance of perennial ryegrass at various proportions in the mixtures with red clover and lucerne, and how different levels of N fertilization affect its competitiveness. Ryegrass achieved the highest yield with lucerne at seeding rate 50:50 and with red clover at seeding rate 70:30. Relative grass yield (RYg) of mixtures ranged from 1.01 to 1.55 respectively, which means that ryegrass in mixtures achieved 0.1-55% greater yield than pure ryegrass crop. N fertilization increased DMY and RYg, leaf : steam ratio, specific leaf area (SLA), leaf area ratio (LAR) and leaf area index (LAI) in both years thus increasing the competitive capability of perennial ryegrass.

scholarly journals Weed Suppression by Cover Plants in the Amazonian

2019 ◽  
Vol 11 (7) ◽  
pp. 148
Author(s):  
Leandro Amorim Damasceno ◽  
José Eduardo Borges Carvalho ◽  
Francisco Alisson Xavier ◽  
Ansselmo Ferreira dos Santos ◽  
Gerlândio Suassuna Gonçalves ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Cover Crops ◽  
Dry Matter ◽  
Block Design ◽  
Area Ratio ◽  
Weed Suppression ◽  
Leaf Area Ratio ◽  
Area Index ◽  
Jack Bean

The productivity of citrus plants has not reached its maximum potential due to the action of several factors that directly affect agricultural profitability. Among these factors, weed interference has a great importance since it causes a reduction in crop productivity. The aim of this study was to assess the effect of different cover crops on suppression of weeds in an orange orchard. The research was conducted in a commercial orange production area located in Rio Preto da Eva, AM, Brazil. The experimental design was a randomized block design with six treatments and four replications. Treatments were control, millet, jack bean, forage turnip, brachiaria, millet + jack bean. The evaluated characteristics were weed density, soil cover percentage, total weed dry matter, total cover plant dry matter and growth indices (leaf area index, leaf area ratio, and specific leaf area). Cover plants provided a good dry matter production and had a suppressive effect on weed growth, except for forage turnip. Brachiaria and jack bean presented the highest values of leaf area index and leaf area ratio.

scholarly journals An Improved Canopy Integration Scheme for a Land Surface Model with Prognostic Canopy Structure

2007 ◽  
Vol 20 (15) ◽  
pp. 3902-3923 ◽  
Author(s):  
Peter E. Thornton ◽  
Niklaus E. Zimmermann
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Land Surface ◽  
Temperate Climate ◽  
Integration Scheme ◽  
Surface Model ◽  
Area Index ◽  
Climate System Model ◽  
Community Land Model ◽  
Canopy Model

Abstract A new logical framework relating the structural and functional characteristics of a vegetation canopy is presented, based on the hypothesis that the ratio of leaf area to leaf mass (specific leaf area) varies linearly with overlying leaf area index within the canopy. Measurements of vertical gradients in specific leaf area and leaf carbon:nitrogen ratio for five species (two deciduous and three evergreen) in a temperate climate support this hypothesis. This new logic is combined with a two-leaf (sunlit and shaded) canopy model to arrive at a new canopy integration scheme for use in the land surface component of a climate system model. An inconsistency in the released model radiation code is identified and corrected. Also introduced here is a prognostic canopy model with coupled carbon and nitrogen cycle dynamics. The new scheme is implemented within the Community Land Model and tested in both diagnostic and prognostic canopy modes. The new scheme increases global gross primary production by 66% (from 65 to 108 Pg carbon yr−1) for diagnostic model simulations driven with reanalysis surface weather, with similar results (117 PgC yr−1) for the new prognostic model. Comparison of model predictions to global syntheses of observations shows generally good agreement for net primary productivity (NPP) across a range of vegetation types, with likely underestimation of NPP in tundra and larch communities. Vegetation carbon stocks are higher than observed in forest systems, but the ranking of stocks by vegetation type is accurately captured.

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