Consulta: subjectFacets:"PAR"
Registros recuperados: 4
Data/hora: 10/06/2024 08:20:51

Growth responses of Betula pendula ecotypes to red and far-red light
Provedor de dados: 69
Autores: Tsegay,Berhanu A.; Lund,Leidulf; Nilsen,Jarle; Olsen,Jorunn E.; Molmann,Jorgen M.; Ernsten,Arild; Juntttila,Olavi.
The effect of Red light (R), Far-red light (FR) and R/FR combinations on shoot growth of latitudinal ecotypes of B. pendula was studied using special diodes that emit monochromatic lights. When a 12 hrs PAR (110 &amp;micro;mol m-2 s-1) was extended with R, FR or R/FR ratios, lower intensities of monochromatic lights could not prevent growth cessation. At 25 &amp;micro;mol m-2 s-1, FR compared to R enhanced stem elongation in all ecotypes. This was due to the inhibitive effect of R on internode elongation. When day-length was extended by R/FR at various ratios, there was continuous shoot elongation, but was found to be declining with increasing ratios. The more the R, the shorter were the internodes of each plant. B. pendula ecotypes produced branches when...
Tipo: Journal article
Palavras-chave: Diode; Ecotype; Monochromatic; Photomorphogenesis; Phytochrome; Photosynthetically active radiation; PAR.
Ano: 2005
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100005

Métodos não destrutivos para estimativa de densidade de área foliar em mangueira
Provedor de dados: 86
Autores: Antunes Junior,Mario Zortéa; Ferronato,Alessandro; Ferronato,Susan Dignart; Rodrigues,Katiuscia; Gallon,Márcia Martim Pereira; Gomes,Nídia Martineia Guerra; Stieven,Ana Carla; Campelo Júnior,José Holanda.
O objetivo deste trabalho foi estimar o número de folhas de ramos do dossel de cultivares de mangueira e estimar a densidade de área foliar utilizando, respectivamente, uma relação alométrica e um modelo de interceptação de luz. O trabalho foi conduzido com as cultivares Alfa, Roxa e Malind, na fazenda experimental da Universidade Federal de Mato Grosso, no Município de Santo Antônio do Leverger, MT. As equações testadas para a determinação do número de folhas apresentaram desempenho ótimo, com índices de confiança que variaram entre 0,85 e 0,94, e podem ser utilizadas como alternativa para a estimativa da área foliar das três cultivares. O modelo de interceptação da luz também apresentou desempenho ótimo e bom na estimativa da densidade foliar, com...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mangifera indica; Lei de Beer-Lambert; PAR.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001200009

Phytotoxic effect of plant extracts on physiology of cotton (Gossypium hirsutum L.) plants
Provedor de dados: 87
Autores: N. Zahoor,Muhammad; Nadeem,Muhammad; Iqbal,Jamshaid; F. Shahzad,Muhammad; Islam,Tahir; A. Begum,Hussan; S. Baloch,Mohammad; Ullah,Ayat.
Abstract  Background:  Plant-derived compounds are alternatives of synthetic insecticides in sustainable agriculture.  Objective:  This study investigated the phytotoxic effect of higher concentrations (2, 4, 8 and 16%) of four plants extracts (Azadirachta indica, Mentha arvensis, D. stramonium and Citrus limonium) on cotton plants.  Methods:  Each concentration was replicated four times to check the phytotoxic effect (CO2-in, CO2-out, H2O-in, H2O-out and photosynthesis absorption rate (PAR) in randomized complete block design. Data was recorded after 12, 24, 48 and 72 hours of spray with the help of Photosynthetic CL 340 meter.  Results:  The results showed that CO2-in was more affected by the D. stramonium (131.65±0.38) at 8% concentration. The overall...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Synthetic insecticides; Plant extract; Cotton; PAR.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100314

Influence of double cropping on growth and yield of dry beans with colored plastic mulches
Provedor de dados: 117
Autores: Ibarra-Jiménez,Luis; Valdez-Aguilar,Luis Alonso; Cárdenas-Flores,Antonio; Lira-Saldivar,Hugo; Lozano-del Río,Javier; Lozano Cavazos,Carlos.
There are numerous studies of the use of plastic mulches in vegetable production, but there is little documentation of their use with dry beans (Phaseolus vulgaris L.) in single and double cropping. The objective of this study was to grow dry beans over two consecutive growing seasons using the same plastic mulch of different colors and examine the influence of soil temperature on growth and yield. The experiment was conducted in Saltillo, Coahuila, Mexico, in the spring and summer of 2008. The treatments included four colored plastic mulches: white-on-black, black, silver-on-black, aluminum-on-black, and bare soil as a control. The experimental design was a randomized complete block with four replicates. The percentage of photosynthetically active...
Tipo: Journal article
Palavras-chave: Phaseolus vulgaris; Soil temperature; Photosynthesis; PAR; Plasticulture.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000400002