scholarly journals Biomass reduction of Salvinia molesta exposed to copper sulfate pentahydrate (CuSO4.5H2O)

Author(s):  
João Pedro Alves de Azevedo Barros ◽  
Matheus Nicolino Peixoto Henares

Copper in the aquatic ecosystem may remain adsorbed or be incorporated into the biomass and undergo biomagnification causing unwanted effects to aquatic macrophyte communities. This study evaluated the biomass reduction of Salvinia molesta (Mitchell) exposed to copper sulphate pentahydrate (CuSO4.5H2O) under laboratory conditions. Approximately 20.5 g of fresh mass (FM) of S. molesta (0.74 g dry matter, DM) were placed in glass tanks with different concentrations (n = 3) of CuSO4.5H2O as follows: 0.0; 2.0; 4.0; 6.0; and 8.0 mg L-1 for 28 days. The dry mass was determined after each seven-day interval over 28 days and submitted to repeated ANOVA measures, followed by a Tukey test (P

2021 ◽  
Vol 22 ◽  
Author(s):  
José Ricardo dos Santos Filho ◽  
Bráulio Maia de Lana Sousa ◽  
Jailson Lara Fagundes ◽  
Alfredo Acosta Backes ◽  
José William Teles Silva ◽  
...  

Abstract The objective of this study was to evaluate the productive and structural characteristics of Paiaguas palisadegrass established in monoculture and intercropped with agricultural crops in 2018 and 2019. The evaluated treatments were: Paiaguas palisadegrass (PP) in monoculture, PP intercropped with maize, PP intercropped with sorghum, and PP intercropped with soybean. The experimental design used was a randomized block, with 4 replications (plots of 160 m²). Sward height, tiller density, dry mass production, and bulk density of total dry matter, of leaves, of stems, and of dead material were evaluated. The data were analyzed using the Tukey test at 5% probability. The total dry mass was higher in intercropping than in monoculture. Paiaguas palisadegrass intercropped with maize showed lower productions of total dry mass, leaf blade, and stems. The percentage of leaf blades was higher in Paiaguas palisadegrass intercropped in 2018 and in monoculture and intercropped with maize and soybean in 2019. Higher percentages of stems were registered in Paiaguas palisadegrass in monoculture in 2018 and in intercropping with sorghum in 2018 and 2019. In general, higher heights were found in Paiaguas palisadegrass in monoculture and smaller when intercropped with maize. The highest tiller densities were observed in Paiaguas palisadegrass in monoculture and the lowest in Paiaguas palisadegrass intercropped with maize and sorghum. Intercropping with agricultural crops reduces the production of Paiaguas palisadegrass. The accompanying agricultural crops alter the composition of the forage produced by the Paiaguas palisadegrass.


Nativa ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 167-172
Author(s):  
Maristênio Alves Santana ◽  
Vitorio Antonio Pereira De Souza ◽  
Miryan Franciele Pereira Serpa ◽  
Alex Aguiar Ledo ◽  
Arianna Santana De Menezes

A palma forrageira representa excelente alternativa de cultivo para o semiárido brasileiro por adaptar-se bem as condições edafoclimáticas da região. O objetivo desse trabalho foi avaliar as características morfométricas e a produtividade de duas espécies de palma forrageira submetidas a diferentes doses de adubação orgânica. O delineamento experimental utilizado foi em blocos casualizados em esquema fatorial 4 x 2, com 4 repetições, sendo quatro doses de adubação orgânica e duas espécies. As características avaliadas foram: comprimento do cladódio, largura do cladódio, número de cladódios, altura das plantas, altura total dos cladódios, área do cladódio, índice de área dos cladódios, produção de massa verde e produção de massa seca. Os dados foram submetidos a análise de variância. O teste de Tukey (P<0,05) foi usado para comparação das médias das espécies e para doses de adubo foram gerados gráficos a partir das regressões.  Para as características morfométricas e de produção observou-se efeito significativo para as doses de esterco bovino sob todos os parâmetros analisados. A máxima produção de matéria seca foi observada, quando se aplicou 75 t ha-1 de esterco bovino. A palma ‘Gigante’ apresenta maior produção de matéria seca quando comparada a ‘Sem espinho’. Palavras-chave: Nopalea cochenillifera; Opuntia fícus-indica; semiárido.   Effect of organic fertilization doses on forage palm production   ABSTRACT: The forage palm represents an excellent cultivation alternative for the Brazilian semi-arid, as it adapts well to the region's edaphoclimatic conditions. The objective of this work was to evaluate the morphometric characteristics and the productivity of two species of forage palm submitted to different doses of organic fertilization. The experimental design used was in randomized blocks in a 4 x 2 factorial scheme, with 4 replications, with four doses of organic fertilization and two species. The characteristics evaluated were: length of the cladode, width of the cladode, number of cladodes, plant height, total height of the cladodes, area of ​​the cladode, index of the area of ​​the cladodes, production of green mass and production of dry mass. The data were subjected to analysis of variance. The Tukey test (P <0.05) was used to compare the means of the species and for fertilizer doses, graphs were generated from the regressions. For the morphometric and production characteristics, a significant effect was observed for the doses of bovine manure under all parameters analyzed. Maximum dry matter production was observed when 75 t ha-1 of bovine manure was applied. The ‘Gigante’ palm has a higher production of dry matter when compared to ‘Sem espinho’. Keywords: Nopalea cochenillifera; Opuntia fícus-indica; semiarid.


Author(s):  
H. Gross ◽  
H. Moor

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.


2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.


2017 ◽  
Vol 13 (3) ◽  
pp. 81-94
Author(s):  
Tariq A. AL- Dhahir ◽  
◽  
Nabeel A. Bakr ◽  
Saja B. Mohammed

1999 ◽  
Vol 26 (8) ◽  
pp. 737 ◽  
Author(s):  
Marcus Schortemeyer ◽  
Owen K. Atkin ◽  
Nola McFarlane ◽  
John R. Evans

The interactive effects of nitrate supply and atmospheric CO2 concentration on growth, N2 fixation, dry matter and nitrogen partitioning in the leguminous tree Acacia melanoxylon R.Br. were studied. Seedlings were grown hydroponically in controlled-environment cabinets for 5 weeks at seven 15N-labelled nitrate levels, ranging from 3 to 6400 mmol m–3. Plants were exposed to ambient (~350 µmol mol–1) or elevated (~700 µmol mol–1) atmospheric CO2 for 6 weeks. Total plant dry mass increased strongly with nitrate supply. The proportion of nitrogen derived from air decreased with increasing nitrate supply. Plants grown under either ambient or elevated CO2 fixed the same amount of nitrogen per unit nodule dry mass (16.6 mmol N per g nodule dry mass) regardless of the nitrogen treatment. CO2 concentration had no effect on the relative contribution of N2 fixation to the nitrogen yield of plants. Plants grown with ≥50 mmol m–3 N and elevated CO2 had approximately twice the dry mass of those grown with ambient CO2 after 42 days. The rates of net CO2 assimilation under growth conditions were higher per unit leaf area for plants grown under elevated CO2. Elevated CO2 also decreased specific foliage area, due to an increase in foliage thickness and density. Dry matter partitioning between plant organs was affected by ontogeny and nitrogen status of the plants, but not by CO2 concentration. In contrast, plants grown under elevated CO2 partitioned more of their nitrogen to roots. This could be attributed to reduced nitrogen concentrations in foliage grown under elevated CO2.


1995 ◽  
Vol 74 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Erling S. Nordøy

Mammals are known to utilize wax esters with an efficiency of less than 50%. The purpose of the present study was to examine whether or not minke whales (Balaenoptera acutorostrata), which at times may eat considerable amounts of wax-ester-rich krill, represent an exception to this general pattern. Samples of fresh undigested forestomach, as well as colon, contents were obtained from minke whales (n5) that had been feeding on krill (Thysanoessa inermis) for some time. The samples were analysed for dry mass, energy density, lipid content and the major lipid classes, including wax esters. The concentrations of wax esters were compared with previous estimates of dry-matter disappearance of the same type of prey using anin vitrotechnique, to calculate the dry-matter digestibility of wax esters (DMDwax). Wax esters contributed 21% of the energy and 47% of total lipids in the krill diet. The energy density of gut contents decreased by 50% after their passage from forestomach to the end of the colon. The DMDwaxwas 94·1 (SD 2·8)% (n5). This high DMDwaxand the occurrence of fatty alcohols, one of the products of wax-ester hydrolysis, in faeces show that minke whales are very efficient digesters of wax esters and absorb most of the energy-rich products of this process.


2017 ◽  
Vol 9 (11) ◽  
pp. 283 ◽  
Author(s):  
Renata V. Menezes ◽  
André D. Azevedo Neto ◽  
Hans R. Gheyi ◽  
Alide M. W. Cova ◽  
Hewsley H. B. Silva

Basil (Ocimum basilicum L.) is a medicinal species of Lamiaceae family, popularly known for its multiple benefits and high levels of volatile compounds. The species is considered to be one of the most essential oil producing plants. Also cultivated in Brazil as a condiment plant in home gardens. The objective of this study was to evaluate the effect of salinity on the growth of basil in nutrient solution of Furlani and to identify variables related to the salinity tolerance in this species. The first assay was performed with variation of five saline levels (0 - control, 20, 40, 60 and 80 mM NaCl). In the second assay six genotypes were evaluated in two salinity levels 0 and 80 mM NaCl. The height, stem diameter, number of leaves, dry mass and inorganic solutes in different organs, photosynthetic pigments, absolute membrane integrity and relative water content were evaluated. All biometric variables in basil were significantly reduced by salinity. Dry matter yield and percentage of membrane integrity were the variables that best discriminated the characteristics of salinity tolerance among the studied basil genotypes. Basil genotypes showed a differentiated tolerance among the genotypes, the ‘Toscano folha de alface’ being considered as the most tolerant and ‘Gennaro de menta’ as the most sensitive, among the species studied.


2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.


2004 ◽  
Vol 61 (5) ◽  
pp. 496-500 ◽  
Author(s):  
Anacleto Ranulfo dos Santos ◽  
Waldssimiler Teixeira de Mattos ◽  
Ana Aparecida da Silva Almeida ◽  
Francisco Antonio Monteiro ◽  
Beatriz Dias Corrêa ◽  
...  

Alfalfa cultivar Crioula (Medicago sativa cv. Crioula) is grown in South Brazil and only a few studies on the plants' boron requirement are available. A greenhouse experiment was carried out with alfalfa to measure boron acquisition, production and distribution in the plant; data on critical level and production potentials were recorded. Plants were grown in ground quartz added with 1 L of solution, with the following boron rates: 0, 0.0625, 0.125, 0.25, 0.50, 1.00, and 2.00 mg L-1. Plants were harvested at 46 days of growth. Forage dry mass was increased by boron supply and dry matter accumulation was considerably low in control. Boron concentration in the leaves was higher than in the stems or roots. Boron utilization from the external solution reached 90% at 0.0625 mg L-1 and sharply decreased with further increasing boron rates. Boron concentration and content in the leaves and in plant tops were at maximum when applied boron was between 1.5 and 1.6 mg L-1. Critical levels of boron in plant were 61 mg kg-1 in the leaves and 39 mg kg-1 in plant tops for this cultivar of alfalfa.


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