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 Evaluation of competitive ability of perennial ryegrass in mixtures with red clover and lucerne subjected to different levels of N

2018 ◽  
Vol 34 (4) ◽  
pp. 455-467
Author(s):  
Zorica Bijelic ◽  
Violeta Mandic ◽  
Dragana Ruzic-Muslic ◽  
Vesna Krnjaja ◽  
Aleksandar Simic ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Competitive Ability ◽  
Relative Yield ◽  
Red Clover ◽  
N Fertilization ◽  
Competitive Balance ◽  
Nitrogen Levels ◽  
Use Of Resources ◽  
Positive Traits ◽  
Different Levels

Grass-legume mixtures represent complex communities of grasses and legumes that make better use of resources and have a number of positive traits in comparison to monoculture. The aim of our research was to examine competitive ability of perennial ryegrass in mixtures with lucerne and red clover (50/50, 70/30) in condition of fertilization with three different nitrogen levels (0, 50, 100 kg ha-1). Dry matter yield of perennial ryegrass in mixtures with red clover was higher compared to mixtures with lucerne. Nitrogen had a very significant impact on perennial ryegrass production. Added N significantly increase DM production of grass treatment with 100 kgN ha-1. The values, of relative yield above 1 (RY >1), aggressivity index and competitive balance index, above 0 (Ag > Cbg > 0) indicated higher competitive ability of perennial ryegrass in relation to legumes. Competitive ability of ryegrass was higher in 70/30 mixtures and mixtures with lucerne. N fertilization increases competitive ability of ryegrass and decreases competitive ability of legumes.

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 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 Impact of Overseeded Grass Species, Seeding Rate and Seeding Time on Establishment and Persistence in Bermudagrass

2011 ◽  
Vol 29 (2) ◽  
pp. 75-80
Author(s):  
Thomas Serensits ◽  
Matthew Cutulle ◽  
Jeffrey F. Derr
Keyword(s):  
Perennial Ryegrass ◽  
Ground Cover ◽  
Italian Ryegrass ◽  
Grass Species ◽  
Percent Cover ◽  
Seeding Rate ◽  
Cool Season ◽  
Seeding Time ◽  
One Year ◽  
Cool Season Grass

Abstract Cool-season grass species are often overseeded into bermudagrass turf for both aesthetics and functionality during the winter months. When the overseeded grass persists beyond the spring, however, it becomes a weed. Experiments were conducted to evaluate overseeded grass species and seeding rate on turf cover during the fall, spring, and summer. The ability of perennial ryegrass, Italian ryegrass, and hybrid bluegrass to then persist in bermudagrass one year after seeding was determined. Both perennial ryegrass and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally had the most persistence one year after seeding, either because of the survival of plants through the summer or because of new germination the following fall. The highest cover seen one year after seeding was 24% with perennial ryegrass in the 2005 trial. Maximum cover seen with Italian ryegrass and hybrid bluegrass 12 months after seeding was 19 and 8%, respectively. Seeding perennial or Italian ryegrass in February achieved acceptable cover in spring in the first trial but not the second. Persistence the following fall, however, was greater in the second trial, suggesting new germination. Percent cover 12 months after seeding tended to increase as the seeding rate increased, also suggesting new germination the following fall. Although quality is lower with Italian ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year after fall seeding.

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.

scholarly journals Fitness Cost of Imazamox Resistance in Wild Poinsettia (Euphorbia heterophylla L.)

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Weight ◽  
Area Ratio ◽  
Fitness Cost ◽  
Seed Plant ◽  
Growth Indices ◽  
Relative Growth ◽  
Net Assimilation

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.

RESPOSTAS MORFOAGRONÔMICAS DE MILHO SUBMETIDO A DESFOLHA ARTIFICIAL

2017 ◽  
Vol 16 (3) ◽  
pp. 460
Author(s):  
EMERSON TROGELLO ◽  
LUAN FERREIRA BORGES ◽  
FÁBIO ARAÚJO DE OLIVEIRA ◽  
QUÉZIA SANCHES MUTAGUTI ◽  
INGRID GOMIDES BARROS ◽  
...  
Keyword(s):  
Zea Mays ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Analysis Of Variance ◽  
Zea Mays L ◽  
Grain Weight ◽  
Area Index ◽  
Plant Removal ◽  
And Control ◽  
Different Levels

RESUMO - O objetivo deste estudo foi avaliar as características morfoagronômicas do híbrido simples de milho em função da aplicação de diferentes intensidades de desfolha artificial, realizadas no estádio R1 de desenvolvimento. O experimento foi conduzido na área experimental do Instituto Federal Goiano,em Morrinhos-GO, na safra 2015/2016. Foi aplicado o delineamento de blocos completamente casualizados, com oito tratamentos e quatro repetições, sendo eles: remoção de uma folha acima e uma abaixo da espiga; remoção de duas folhas acima e abaixo da espiga; remoção de três folhas acima e abaixo da espiga; remoção de todas as folhas da planta; remoção de todas as folhas acima da espiga; remoção de todas as folhas abaixo da espiga; remoção da folha da espiga; e testemunha sem desfolha. Os caracteres avaliados foram: estande de plantas, número de plantas acamadas, prolificidade, densidade de colmo, comprimento e diâmetro de espiga, comprimento de grão, massa de mil grãos, massa de grãos espiga-1 e produtividade. Os dados foram submetidos à análise de variância pelo teste F a 5% de probabilidade, observando que todas as variáveis avaliadas foram influenciadas quanto aos efeitos dos tratamentos empregados. O enchimento dos grãos esteve intimamente relacionado à fotossíntese. Sem as folhas, esta fase ficou plenamente comprometida.Palavras-chave: Zea mays, fotoassimilados, translocação, índice de área foliar, rendimento. MORPHOAGRONOMIC CHARACTERISTICS OF MAIZE AS A FUNCTION OF DIFFERENT LEVELS OF ARTIFICIAL DEFOLIATION  ABSTRACT - The objective of this study was to evaluate of morphoagronomic characteristics of simple hybrids of maize, depending on the application of different intensities of artificial defoliation, carried out in R1, when the style-stigma were fertilized. The experiment was conducted in an experimental area of the Instituto Federal Goiano, Campus Morrinhos, State of Goiás, Brazil, during the agricultural year 2015/2016. We applied the design of completely randomized block with eight treatments, in four replications: removal of a leaf above and one below the ear; removal of two leaves above and below the ear; removal of three leaves above and below the ear; removal of all leaves of the plant; removal of all leaves above the ear; removal of all leaves below the ear; removal of the leaf of the ear; and control without defoliation. The traits evaluated were stand of plants, number of plant lodging, prolificacy, density, length and diameter of the cob, length of a grain, weight of a thousand grains, grain mass cob-1 and productivity. The data obtained were subjected to analysis of variance by F test at 5% probability, noting that all variables were influenced as to the effects of the treatments used. The filling of grains is closely related to photosynthesis. Without the leaves, this phase was fully damaged.Keywords: Zea mays L., photoassimilates, translocation, leaf area index, yield.

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