Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Semina ciênc. agrar ; 41(05, supl. 01): 1897-1908, 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1501606

Resumo

Salinity is one of the most problematic abiotic stresses in agriculture globally, especially in semi-arid regions. Thus, the application of nutrients, such as nitrogen and potassium to improve plant nutritional conditions may be a viable alternative to minimize the negative effects of saline stress. Therefore, the aim of this study was to evaluate the morphophysiological behavior of yellow passion fruit seedlings under varying nitrogen and potassium doses and irrigation with salt water. The experimental design was a randomized complete block with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Design with five electrical conductivities of irrigation water (0.5, 0.98, 2.15, 3.32, and 3. 80dS m-¹) and five increasing doses of nitrogen and potassium (0.0, 29.08, 100.0, 170.92, and 200.0%). Leaf, stem, and root dry phytomass and gas exchange were evaluated 75 days after sowing. The increase in salinity had negative effects on the morphological and physiological characteristics of yellow passion fruit seedlings. The application of nitrogen and potassium positively influenced photosynthetic rate and leaf and root dry phytomasses. The application of nitrogen and potassium increased intercellular CO2 concentration and transpiration in yellow passion fruit seedlings under saline stress.


A salinidade é um dos estresses abióticos mais preocupantes na agricultura mundial, principalmente nas regiões semiáridas. Assim, a aplicação de nutrientes como nitrogênio e o potássio visando melhorar as condições nutricionais das plantas pode ser uma alternativa viável para minimizar os efeitos negativos do estresse salino. Portanto, objetivou-se avaliar o comportamento morfofisiológico de mudasd e maracujazeiro-amarelo sob doses de nitrogênio e potássio e irrigadas com águas salinas. O delineamento utilizado foi em blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco condutividades elétricas da água de irrigação (0,5; 0,98; 2,15; 3,32 e 3,80 dS m-¹) e cinco doses crescentes de nitrogênio e potássio (0,0; 29,08; 100,0; 170,92 e 200,0%). Foram avaliadas as fitomassas seca de folha, caule e raiz e as trocas gasosas aos 75 dias após a semeadura. O aumento da salinidade proporciona efeitos negativos nas características morfofisiológicas do maracujazeiro amarelo. A aplicação de nitrogênio e potássio influencia positivamente na taxa fotossintética e fitomassa seca das folhas e raiz. A aplicação de nitrogênio e potássio aumenta concentração intercelular de CO2 e transpiração de mudas de maracujazeiro-amarelo sob estresse salino.


Assuntos
Estresse Salino , Nitrogênio/administração & dosagem , Passiflora/anatomia & histologia , Passiflora/efeitos dos fármacos , Passiflora/fisiologia , Potássio/administração & dosagem
2.
Semina Ci. agr. ; 41(05, supl. 01): 1897-1908, 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-764772

Resumo

Salinity is one of the most problematic abiotic stresses in agriculture globally, especially in semi-arid regions. Thus, the application of nutrients, such as nitrogen and potassium to improve plant nutritional conditions may be a viable alternative to minimize the negative effects of saline stress. Therefore, the aim of this study was to evaluate the morphophysiological behavior of yellow passion fruit seedlings under varying nitrogen and potassium doses and irrigation with salt water. The experimental design was a randomized complete block with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Design with five electrical conductivities of irrigation water (0.5, 0.98, 2.15, 3.32, and 3. 80dS m-¹) and five increasing doses of nitrogen and potassium (0.0, 29.08, 100.0, 170.92, and 200.0%). Leaf, stem, and root dry phytomass and gas exchange were evaluated 75 days after sowing. The increase in salinity had negative effects on the morphological and physiological characteristics of yellow passion fruit seedlings. The application of nitrogen and potassium positively influenced photosynthetic rate and leaf and root dry phytomasses. The application of nitrogen and potassium increased intercellular CO2 concentration and transpiration in yellow passion fruit seedlings under saline stress.(AU)


A salinidade é um dos estresses abióticos mais preocupantes na agricultura mundial, principalmente nas regiões semiáridas. Assim, a aplicação de nutrientes como nitrogênio e o potássio visando melhorar as condições nutricionais das plantas pode ser uma alternativa viável para minimizar os efeitos negativos do estresse salino. Portanto, objetivou-se avaliar o comportamento morfofisiológico de mudasd e maracujazeiro-amarelo sob doses de nitrogênio e potássio e irrigadas com águas salinas. O delineamento utilizado foi em blocos casualizados, em esquema fatorial incompleto 5x5, gerados a partir da matriz Composto Central de Box com cinco condutividades elétricas da água de irrigação (0,5; 0,98; 2,15; 3,32 e 3,80 dS m-¹) e cinco doses crescentes de nitrogênio e potássio (0,0; 29,08; 100,0; 170,92 e 200,0%). Foram avaliadas as fitomassas seca de folha, caule e raiz e as trocas gasosas aos 75 dias após a semeadura. O aumento da salinidade proporciona efeitos negativos nas características morfofisiológicas do maracujazeiro amarelo. A aplicação de nitrogênio e potássio influencia positivamente na taxa fotossintética e fitomassa seca das folhas e raiz. A aplicação de nitrogênio e potássio aumenta concentração intercelular de CO2 e transpiração de mudas de maracujazeiro-amarelo sob estresse salino.(AU)


Assuntos
Passiflora/efeitos dos fármacos , Passiflora/anatomia & histologia , Passiflora/fisiologia , Nitrogênio/administração & dosagem , Potássio/administração & dosagem , Estresse Salino
3.
Acta sci., Biol. sci ; 41: e43494, 20190000. ilus, map, tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1460869

Resumo

Determining leaf area is important for studies involving plant growth and development. The aim of the present study was to obtain models for estimating leaf area of Psychotria carthagenensis and Psychotria hoffmannseggiana using linear measurements of leaf blades (length and width). Two hundred leaf blades of each species were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, Paraíba, Northeast Brazil. The equations evaluated for producing potential models included the following: linear, quadratic, potential and exponential. The criteria used to determine the best model(s) were as follows: high coefficient of determination (R²), low root-mean-square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance index (d) and a BIAS ratio close to zero. All evaluated models satisfactorily estimated leaf area for the two species, but the equation ŷ = 0.6373 * LW0.9804 was the most appropriate for P. carthagenensis, while ŷ = 0.6235 * LW0.9712 was the most appropriate for P. hoffmannseggiana.


Assuntos
Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Psychotria/anatomia & histologia
4.
Acta sci., Biol. sci ; 41: e46030, 20190000. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1460901

Resumo

Erythroxylum pauferrense is an endemic understory plant species of the Northeast Region of Brazil. The species is of great importance to the region and so ecophysiological studies are needed for its preservation. The objective of the present study was to determine the best substrates and temperatures for testing germination and seed vigor of E. pauferrense. An experiment was performed comprising a completely randomized design in a 5 x 4 factorial scheme, with five temperature regimes (20, 25, 30, 35°C constant and 20-30°C alternating) and four types of substrates (paper, vermiculite, sand and commercial substrate). The following characteristics were evaluated: germination percentage, first germination count, germination speed index, mean germination time, seedling length and dry mass (root and shoot). Paper and vermiculite substrates combined with constant temperatures of 20, 25, 30 and alternated between 20-30°C, provide greater seed germination and vigor while 35°C reduces seed physiological quality.


Assuntos
Erythroxylaceae/fisiologia , Germinação/fisiologia , Vigor Híbrido
5.
Acta Sci. Biol. Sci. ; 41: e43494, 2019. ilus, mapas, tab, graf
Artigo em Inglês | VETINDEX | ID: vti-763463

Resumo

Determining leaf area is important for studies involving plant growth and development. The aim of the present study was to obtain models for estimating leaf area of Psychotria carthagenensis and Psychotria hoffmannseggiana using linear measurements of leaf blades (length and width). Two hundred leaf blades of each species were collected in Parque Estadual Mata do Pau-Ferro in the municipality of Areia, Paraíba, Northeast Brazil. The equations evaluated for producing potential models included the following: linear, quadratic, potential and exponential. The criteria used to determine the best model(s) were as follows: high coefficient of determination (R²), low root-mean-square error (RMSE), low Akaike information criterion (AIC), high Willmott concordance index (d) and a BIAS ratio close to zero. All evaluated models satisfactorily estimated leaf area for the two species, but the equation ŷ = 0.6373 * LW0.9804 was the most appropriate for P. carthagenensis, while ŷ = 0.6235 * LW0.9712 was the most appropriate for P. hoffmannseggiana.(AU)


Assuntos
Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Psychotria/anatomia & histologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA