scholarly journals FLAME RETARDANTS EFFECTS ON THE INITIAL GROWTH OF Schizolobium amazonicum HUBER EX DUCKE

2021 ◽  
Vol 45 ◽  
Author(s):  
Elen Silma Oliveira Cruz Ximenes ◽  
Andréa Carvalho da Silva ◽  
Adilson Pacheco de Souza ◽  
Josiane Fernandes Keffer ◽  
Alison Martins dos Anjos ◽  
...  

ABSTRACT Flame retardants are efficient in fighting wildfire; however, their environmental implications, especially regarding the vegetation, need to be clarified. This work aimed at assessing the effects of flame retardant on the initial growth of Schizolobium amazonicum. Treatments consisted in applying different flame retardant concentrations via substrate and leaf: Phos-Chek WD-881® (0, 3.00, 6.00, 8.00 and 10.00 mL L-1), Hold Fire® (0, 7.00, 9.00, 12.00 and 15.00 mL L-1) and water-retaining polymer Nutrigel® used as alternative retardant (0, 0.25, 0.50, 0.75 and 1.00 g L-1). Growth analyses were carried out to assess the effects of these substances (10 repetitions per treatment). The aliquot of 10.00 mL L-1 of Phos-Chek WD881 applied on the leaves led to an increase of 70% in leaf area and 15% in seedling height. The same Phos-Chek concentration favored height increase (32%) and total dry mass accumulation (33%) throughout time. The concentration of 15 mL L-1 of Hold Fire® applied on leaves, compromised 45% the accumulation of dry biomass in the seedling. Initially, 1.00 g L-1 of Nutrigel® applied via substrate led to an increase of 70% in leaf area, 29% in plant height, and 89% in leaf dry mass. Therefore, Phos-Chek applied on leaves favored shoot growth in S. amazonicum. Hold Fire® applied on leaves impaired biomass accumulation in seedlings. Nutrigel® applied on substrate does not cause long-lasting damage to the initial growth of S. amazonicum. The aliquot of 0.50 g L-1 administered via polymer leave had positive effect on seedling shoot.

2021 ◽  
Vol 24 (5-esp.) ◽  
pp. 584-592
Author(s):  
Josinei Rodrigues Filho ◽  
Viviana Borges Corte ◽  
Idalina Tereza de Almeida Leite Perin ◽  
Rodolpho Waichert da Silva ◽  
Camila Reis

O ferro (Fe) é um nutriente essencial para as plantas, sendo insubstituível ao metabolismo. Todavia, o aumento em sua concentração leva ao acúmulo de espécies reativas de oxigênio e estresse oxidativo que resultará em prejuízos aos vegetais. O objetivo deste trabalho foi verificar o efeito de elevadas concentrações de Fe na germinação e desenvolvimento de Cecropia hololeuca Miq. A espécie foi submetida às concentrações de 0,045, 4 e 8mM aplicados na forma de sulfato ferroso e Fe-EDTA. Foram analisadas a porcentagem de germinação, índice de velocidade de germinação, comprimento da parte aérea, radicular, massa fresca e seca. Para a análise de desenvolvimento foi analisado a área folhar o comprimento do caule, comprimento radicular, massa fresca e seca, os pigmentos cloroplastídeos, fluorescência da clorofila, e análise dos teores de elementos via EDS. Foi verificado a atividade enzimática (SOD, CAT, POX). Ambas as fontes de Fe resultaram em danos à germinação e desenvolvimento. O tratamento com Fe-EDTA mostrou efeitos mais significativos na germinação, crescimento aéreo e radicular e biomassa das sementes. O mesmo tratamento se mostrou mais prejudicial nas plântulas jovens com quedas na clorofila a, crescimento radicular, aéreo, área folhar e biomassa. As plântulas expostas ao Fe apresentaram queda no desempenho fotossintético e no teor de cálcio (Ca) folhar. Não foi observado aumento na atividade da CAT e SOD. A POX apresentou elevação quando submetida ao Fe-EDTA 8mM. Tais resultados evidenciam que a espécie C. hololeuca se mostra sensível a toxidez por ferro, acarretando danos ao metabolismo e crescimento inicial.    Palavras-chave: Embaúba. Estresse. Metal Pesado. Toxidez.  Abstract Iron (Fe) is as an essential nutrient for plants and is irreplaceable in many metabolic processes. However, the increase in its concentration leads to the accumulation of reactive oxygen species and oxidative stress that will result in damage to plant. The objective of this work was to verify the effect of high Fe concentrations on germination and initial development of Cecropia hololeuca Miq. They were submitted to concentrations of 0.045, 4 and 8mM applied as ferrous sulfate and Fe-EDTA. Germination percentage, germination speed index, shoot length and root, fresh and dry mass were analyzed. For the initial developmental the following variables were analyzed: Leaf area, stem length, root length, fresh and dry mass, chloroplast pigments, chlorophyll fluorescence analysis, analysis of element contents via EDS. The activity of enzymes (SOD, CAT, POX) was verified. Both sources of Fe resulted in damage to germination and development. Fe-EDTA treatment showed the most significant negative effects on germination, root and air growth and seed biomass accumulation. The same treatment was more detrimental in the establishment of young seedlings with decreases in chlorophyll a, root growth, aerial growth, leaf area and biomass accumulation. Seedlings exposed to Fe showed a decrease in photosynthetic performance and a decrease in leaf calcium (Ca) content. No increase in CAT and SOD enzymes activity was observed. POX increased its activity when submitted to 8mM Fe-EDTA. These results show that the species C. hololeuca is sensitive when exposed to toxic levels of Fe, causing damage to metabolism and initial growth.   Keywords: Embauba. Stress. Heavy Metal. Toxicity.


Revista CERES ◽  
2018 ◽  
Vol 65 (2) ◽  
pp. 120-126
Author(s):  
Tiago Pacheco Mendes ◽  
Fábio Luiz de Oliveira ◽  
Marcelo Antonio Tomaz ◽  
Wagner Nunes Rodrigues ◽  
Ariany das Graças Teixeira

ABSTRACT The increasing consumption of yacon potato has raised worldwide interest in its crop and generated demand for scientific elucidations of several factors associated to its agricultural management. Among the demands, there are the studies related to the effects of aluminum (Al3+) on the development of yacon plants. Thus, this study was developed to evaluate the effects of aluminum on budding and initial growth of yacon plantlets. The experiment was carried out in a completely randomized block design, with three replications and six aluminum contents in the substrate: 0, 10, 25, 50, 100, and 200 mg L-1. The response of yacon plantlets to aluminum contents was evaluated by the emergence time, emergence speed index, number of leaves, plant height, leaf area, radicle length, and dry mass weight of leaves, stems, and radicles. The presence of aluminum in the substrate negatively influences the emergence and initial growth of yacon, causing losses in foliage development (number of leaves and leaf area), in biomass accumulation, growth and, especially, restricting the development of radicles. Aluminum toxicity fully inhibits radicle growth in substrate contents above 83 mg L-1, under the controlled conditions used in this experiment.


1999 ◽  
Vol 34 (6) ◽  
pp. 944-952 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.


2014 ◽  
Vol 1033-1034 ◽  
pp. 931-936
Author(s):  
Cong Yan Chen ◽  
Rui Lan Fan ◽  
Guan Qun Yun

A novel intumescent flame retardant (IFR) containing ferrocene and caged bicyclic phosphate groups, 1-oxo-4-[4'-(ferrocene carboxylic acid phenyl ester)] amide-2, 6, 7-trioxa-1-phosphabicyclo- [2.2.2] octane (PFAM), was successfully synthesized. The synthesized PFAM were added to flammable polyurethane (PU) as flame retardants and smoke suppressants. The structure of PFAM was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR) and elemental analysis. Thermal stability of PFAM was tested by themogravimetric analysis (TGA). The results revealed that PFAM had good thermal stability and high char weight, the char weight up to 54% at 600 °C. Flammability properties of PU/PFAM composites were investigated by limiting oxygen index (LOI) test and UL-94 test, respectively. The results of LOI tests showed that the addition of PFAM enhanced flame retardancy of PU. When the content of PFAM reaches to 3%, the LOI value is 22.2. The morphologies of the char for PU and PU/3% PFAM composite can be obtained after LOI testing were examined by SEM. The results demonstrated that PFAM could promote to form the compact and dense intumescent char layer. Experiments showed that, the PFAM application of polyurethane showed positive effect.


2020 ◽  
Vol 38 ◽  
Author(s):  
M.O. CABRAL ◽  
F.L. OLIVEIRA ◽  
L.P. DALVI ◽  
A.G. TEIXEIRA ◽  
L.J.F.N. ROCHA ◽  
...  

ABSTRACT: The consumption of yacon has been increasing around the world due to the nutritional and pharmaceutical properties of this plant. The growing commercial interest in yacon (Smallanthus sonchifolius) generates a demand for crop management research studies, including the effect of weed competition on yacon, which was not yet studied. Thus, this study was performed with the objective of evaluating the effects of weed competition on yacon development and growth. The experimental design was completely randomized with four treatments and seven replicates. Treatments were yacon with the interference of four weed species: Cyperus rotundus L. (nutgrass), Commelina benghalensis L. (tropical spiderwort), Amaranthus viridis L. (slender amaranth) and Bidens pilosa L. (hairy beggarticks). The experiment was conducted in a greenhouse, using 10 dm3 pots. Plant height, number of leaves, number of stems, leaf area, fresh and dry mass weight (total and partial), and chlorophyll A, B and total were evaluated. The weed competition resulted in a decrease in the yacon development (height, number of leaves, number of stems, leaf area), photosynthetic rate (decreased chlorophyll content A, B and total) and yield, as also decreased the accumulation of fresh and dry biomass of tuberous roots. C. benghalensis L. and A. viridis L. were the weeds most affecting the development and growth of yacon.


2013 ◽  
Vol 35 (3) ◽  
pp. 853-859 ◽  
Author(s):  
Julián Cárdenas ◽  
Carlos Carranza ◽  
Diego Miranda ◽  
Stanislav Magnitskiy

Passiflora seeds germinate erratically presenting difficulties for their handling in a greenhouse. The effect of removing of basal point of seeds (RB) and pre-imbibition of seeds of sweet granadilla and yellow passion fruit in 50, 100, 200, and 400 mg mL-1 solutions of gibberellic acid (GA3) or 0.1% KNO3 solution was studied. The experiment was conducted in greenhouses in La Plata, Colombia. Two accessions PrJ1 and PrJ2 of sweet granadilla were evaluated. There were calculated the final percentage of germination (PG), mean germination time (MGT), and the mean germination rate (MGR). The leaf area and dry mass of seedlings were measured 22 days after sowing (das); with this data, specific leaf area and relation root/shoot were calculated. In all cases, the highest germination percentages were achieved treating seeds with KNO3 (89, 92, and 87% for yellow passion fruit, PrJ2, and PrJ1, respectively), but the increase in MGR (3.3 germinated seeds per day) and the decrease in MGT (16 days) were only significant for PrJ1. RB had a significant reduction of PG in all cases (28, 12, and 33% for passion fruit, PrJ2 and PrJ1, respectively). With the increase in the concentration of GA3, PG was reduced for two accessions of sweet granadilla, for yellow passion fruit this trend was not clear, no treatment with GA3 showed significant differences with the control. Leaf area (24.07 cm2) and dry mass of seedlings (135 mg) were significantly higher than seeds previously treated with KNO3 only for PrJ1.The solution of KNO3 0,1% is recommended to improve the germination and initial growth of granadilla seedlings.


2011 ◽  
Vol 57 (No. 9) ◽  
pp. 377-383 ◽  
Author(s):  
V. Bayramzadeh ◽  
P. Attarod ◽  
M.T. Ahmadi ◽  
S. Rezaee Amruabadi ◽  
T. Kubo

The relationships between climatic factors and anatomical characteristics of the vessel elements as well as different foliar traits were investigated in Fagus crenata seedlings originating from different provenances. Fagus crenata samples were prepared from Chichibu Research Forest of Tokyo University. In the present study, vessel number per mm<sup>2</sup>, average vessel diameter, vessel area percentage, vessel element length, percentages of perforation plate types, transpiration rate, stomatal conductance, leaf area, leaf thickness, leaf dry mass per unit leaf area, stomatal density and stomatal pore length were measured. Vessel number per mm<sup>2</sup>, vessel area percentage, stomatal conductance, transpiration rate, leaf thickness and leaf dry mass per unit leaf area showed a significant negative correlation with yearly, winter, spring and autumn precipitation. The majority of the studied characteristics were not related to the mean annual and seasonal temperatures of the original provenances. The results suggest that anatomical characteristics of vessel elements and different foliar traits in Fagus crenata are mainly influenced by the precipitation of the origins.


1998 ◽  
Vol 41 (2) ◽  
pp. 207-211 ◽  
Author(s):  
José Pires de Lemos Filho ◽  
Ricardo Jenner Duarte

The aim of this study was to verify the dry mass partition of the seed reserves during the initial growth of Swietenia macrophylla seedlings, in the dark, and at low levels of photosynthetically active radiation: 0.125; 3.12 and 52 µ mol.m-2.s-1. After 50 days, the dry mass of the seed reserves did not differ with treatments, but the total dry mass and leaf area were higher in the seedlings under higher light treatment. No difference in root/shoot ratio was observed between treatments, but the leaf area ratio was lower at higher light. Only the seedlings grown at 52 µ mol.m-2.s-1 showed a positive dry mass increase in relation to the mobilized seed reserves. With the values of the net increase of the seedling mass, a linear equation was adjusted in relation to the light levels, permitting to determine 3.76 µ mol.m-2.s-1 as the seedling light compensation point. These results explain the shade tolerance of the S. macrophylla seedlings.


2016 ◽  
Vol 46 (4) ◽  
pp. 374-382 ◽  
Author(s):  
Fábio Reis Ribeiro Araújo ◽  
◽  
Ismael de Jesus Matos Viégas ◽  
Raimundo Lázaro Moraes da Cunha ◽  
Werica Larissa Farias de Vasconcelos ◽  
...  

ABSTRACT The Amazonian assai palm has a great socioeconomic importance, but most of its commercial plantations take place in uplands and low natural fertility soils, what may hinder its development. This study aimed at evaluating the effect of nutrient omission on growth and nutritional status of assai palm seedlings (Ver-o-Peso cultivar). The experimental design was completely randomized, with 14 treatments and 5 replicates. The treatments consisted of complete fertilization with liming; no fertilization and no liming (control); complete fertilization with individual omission of N, P, K, Ca, Ca with no liming, Mg, Mg with no liming, S, B, Cu and Zn. Plant height, stem diameter and dry mass, leaf and total shoot dry mass, and leaf nutrients content and accumulation were evaluated. The initial growth of the assai palm plants was limited by the omission of P, N, K, Ca, Mg and Cu. The production of leaf dry mass was decreasingly affected by the omission of P > Cu > N > K > Mg, while leaf area was limited by the individual omissions of Ca > N > P > K > Mg > Zn. Plant development, measured by relative growth of shoots, was affected by lack of Ca > P > N > Mg > Cu > K, with an average reduction of 31 %. The nutrients most needed by the assai palm plants, as evidenced by nutrients contents and accumulation in the leaf dry mass, are: N > K > S > Ca > Mg > P > Mn > Zn > B > Cu.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jing-Qiu Feng ◽  
Feng-Ping Zhang ◽  
Jia-Lin Huang ◽  
Hong Hu ◽  
Shi-Bao Zhang

In flowering plants, inflorescence characteristics influence both seed set and pollen contribution, while inflorescence and peduncle size can be correlated with biomass allocation to reproductive organs. Peduncles also play a role in water and nutrient supply of flowers, and mechanical support. However, it is currently unclear whether inflorescence size is correlated with peduncle size. Here, we tested whether orchids with large diameter peduncles bear more and larger flowers than those with smaller peduncles by analyzing 10 traits of inflorescence, flower, and leaf in 26 species. Peduncle diameters were positively correlated with inflorescence length and total floral area, indicating that species with larger peduncles tended to have larger inflorescences and larger flowers. We also found strongly positive correlation between inflorescence length and leaf area, and between total floral area and total leaf area, which suggested that reproductive organs may be allometrically coordinated with vegetative organs. However, neither flower number nor floral dry mass per unit area were correlated with leaf number or leaf dry mass per unit area, implying that the function between leaf and flower was uncoupled. Our findings provided a new insight for understanding the evolution of orchids, and for horticulturalists interested in improving floral and inflorescence traits in orchids.


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