Morphophysiology of Punica Granatum L. under microalgae biomass stimulation

The use of microalgae has been proeminent in agricultural scenario, because it is an alternative product considered extremelly productive, which contains essential elements for plants. Thus, this study aimed to evaluate the morphophysiology of Punica granatum L. seedlings treated with Spirulina platensis and Scenedesmus sp. nanoparticles in controlled environment. The research was carried out at the of Federal University of Campina Grande, Pombal-PB, using a completely randomized design with five replications. The factorial scheme (2 x 4) was adopted, represented by two types of microalgae (Spirulina platensis; Scenedesmus sp.) and four doses of application (0, 5, 10 and 15%). Growth evaluations happened at 135 days after planting, verifying the number of leaves and branches and shoot length. The physiological parameters evaluated were gas exchanges, chlorophyll ‘a’ fluorescence, electron transport rate, stationary fluorescence, maximum fluorescence yield after light adaptation and quantum efficiency of PSII. Shoot length and number of branches had rises at doses of 6 and 15%. Number of leaves was induced in seedlings at dose of 8% with Spirulina platensis. Stomatal conductance and internal CO2 concentration increased in seedlings sprayed with Spirulina platensis. extract of Scenedesmus sp. improved the stationary fluorescence and quantum efficiency of PSII in pomegranate seedlings.The use of microalgae has been proeminent in agricultural scenario, because it is an alternative product considered extremelly productive, which contains essential elements for plants. Thus, this study aimed to evaluate the morphophysiology of Punica granatum L. seedlings treated with Spirulina platensis and Scenedesmus sp. nanoparticles in controlled environment. The research was carried out at the of Federal University of Campina Grande, Pombal-PB, using a completely randomized design with five replications. The factorial scheme (2 x 4) was adopted, represented by two types of microalgae (Spirulina platensis; Scenedesmus sp.) and four doses of application (0, 5, 10 and 15%). Growth evaluations happened at 135 days after planting, verifying the number of leaves and branches and shoot length. The physiological parameters evaluated were gas exchanges, chlorophyll ‘a’ fluorescence, electron transport rate, stationary fluorescence, maximum fluorescence yield after light adaptation and quantum efficiency of PSII. Shoot length and number of branches had rises at doses of 6 and 15%. Number of leaves was induced in seedlings at dose of 8% with Spirulina platensis. Stomatal conductance and internal CO2 concentration increased in seedlings sprayed with Spirulina platensis. extract of Scenedesmus sp. improved the stationary fluorescence and quantum efficiency of PSII in pomegranate seedlings

Plant development, gas exchanges and pigments of Mesosphaerum suaveolens submitted to osmoconditioning and saline stress

Salinity is one of the main plant abiotic stresses affecting the establishment and development of crops. It is thus a matter of prime importance to search for technologies that minimize the damage caused by salinity. The aim of the present work was to evaluate the effect of salinity stress and osmotic conditioning of seeds on the biomass, gas exchanges and chlorophyll pigments in Mesosphaerum suaveolens (L.) Kuntze. The statistical design adopted was a randomized block design, combined according to the central composite design, referring to electrical conductivities of irrigation water and osmotic potentials, with minimum (- α) and maximum (α) values of 0.5 and 10.0 dS m-1 and 0.0 and -1.0 MPa, respectively, totaling nine combinations. The characteristics of dry biomass, gas exchange and chlorophyll indices were evaluated at 45 days after the beginning of irrigation with saline water. The salinity of irrigation water severely affected the dry biomass and the gas exchanges of M. suaveolens. Irrigation water of electrical conductivity above 3.2 dS m-1 caused reductions in chlorophyll a, b and total contents in M. suaveolens plants. Seed osmoconditioning did not attenuate the negative effects of saline stress on M. suaveolens plants

Initial growth of Moringa oleifera Lam. as a function of poultry litter doses and granulometry

There is an increasing use of poultry litter in seedling production. However, studies regarding the effect of different particle-size litter on plant growth are still scarce. This study aimed to evaluate the growth of Moringa oleifera Lam. fertilized with poultry litter doses (0 g dm-3, 40 g dm-3, 80 g dm-3 and 120 g dm-3) with distinct particle sizes (1 mm and 4 mm), with four replications. The following variables were evaluated: plant height; root and stem diameter; leaf, stem, shoot and root dry matter mass; shoot/root dry matter mass ratio; and the Dickson quality index. There was no influence of the particle size on the studied variables, except for plant height. The root diameter decreased with the increase of the poultry litter doses. The accumulation of dry matter mass from the shoot and root increased with the increase of poultry litter doses up to 120 g dm-3. A linear increase of the Dickson quality index, relatively to days and poultry litter doses, was observed. It is recommended to apply 80 g dm-3 of poultry litter to fertilize M. oleifera plants, independently of the granulometry used

Photochemical efficiency and growth of sugar apple under irrigation with saline water and foliar nitrogen

Salt stress has compromised the worldwide expansion of fruit farming by causing damage to light energy regulation and crop growth, which can be mitigated by applying foliar nitrogen (N). From this perspective, this study aimed to evaluate the chlorophyll contents, fluorescence, and the growth of sugar apple seedlings under irrigation with saline water and foliar N fertilisation. The experiment was conducted in a plant nursery and following a randomized block design referring to five electrical conductivity levels of irrigation water (0.5, 1.15, 2.75, 4.35, and 5.0 dS m-1) and five foliar N levels (0.0, 0.33, 1.15, 1.97, and 2.3 g L-1), with four replications and two plants per plot, totaling nine combinations generated by the Box central composite design. Irrigation water salinity reduces the growth of sugar apple seedlings irrigated with conductivity levels over 1.7 dS m-1 at 90 days after emergence. Foliar N fertilisation increased the photochemical efficiency and growth of sugar apple seedlings. The foliar application of 1.93 g L-1 mitigate the deleterious effects of water salinity on the photochemical efficiency and growth of sugar apple seedlings

Basil (Ocimum basilicum) growth under saline stress and salicylic acid

443-449Basil (Ocimum basilicum L.) is an aromatic and spice plant used around the world in cooking, pharmaceutical, cosmetic and flavoring industries. Salicylic acid has been used to mitigate the deleterious effects of salinity on plants. This work aimed to evaluate the growth of basil under saline stress and salicylic acid. A randomized block design was used. Five electrical conductivities of irrigation water (ECw - 0.5, 1.3; 3.25; 5.2 and 6.0 dS m-1) and five salicylic acid doses (SA - 0.0, 0.29, 1.0, 1.71 and 2.0 mM) was used. Plant height, number of leaves, stem diameter, leaf area, specific leaf area, relative growth rate, leaf area ratio, leaf mass ratio, relative leaf growth rate and chlorophyll a, b and total indices were evaluated at 32, 39, 46, 53 and 60 days after irrigation with saline water (DAI). The increase in the electrical conductivity of irrigation water (ECw) negatively affected growth and increased the basil chlorophyll index. The application of salicylic acid attenuated the negative effects of salt stress on the number of leaves and leaf area and had negative effects on the stem diameter, but did not affect the other growth variables and chlorophyll indices

CRESCIMENTO DE ERYTHRINA VELUTINA WILLD. SUBMETIDA A ESTRESSE SALINO E APLICAÇÃO DE ÁCIDO SALICÍLICO

Erythrina velutina is an endemic species of the Northeast region of Brazil, known for displaying pharmacological properties and potential timber. However, its growth may be compromised by abiotic factors such as water scarcity and excess salts. The use of growth regulators such as salicylic acid is among the methods used to mitigate the negative effects of stress on vegetables. The objective of this study was to evaluate the growth of Erythrina velutina seedlings submitted to saline stress and salicylic acid application. The experimental design was a randomized complete block design with a 5 x 5 incomplete factorial scheme, generated from the Central Composite Box matrix with five levels of electrical conductivity of the irrigation water (ECw = 0.5, 1.74, 4.75, 7,76 and 9.0 dS m-1) four doses of salicylic acid (SA = 0.0, 0.29, 1.0, 1.71 and 2.0 mM L-1), with four replicates. The following variables were evaluated: plant height, leaf number, stem diameter, relative and absolute growth rate of height and stem diameter, root dry matter, stem, shoot and total leaf weight and Dickson quality index. Data were submitted to analysis of variance by the F test, in cases of significance was performed polynomial regression analysis. The salinity promotes serious damage to the growth of Erythrina velutina plants, being more pronounced in increasing levels of electrical conductivity. The application of salicylic acid at the concentrations used does not attenuate the effects of salinity.Erythrina velutina é uma espécie endêmica da região Nordeste do Brasil, conhecida por exibir propriedades farmacológicas e potencial madeireiro. Entretanto, seu crescimento pode ser comprometido por fatores abióticos como escassez hídrica e excesso de sais. A utilização de reguladores de crescimento como o ácido salicílico está entre os métodos usados para mitigar os efeitos negativos de estresse nos vegetais. Com isso, objetivou-se avaliar o crescimento de mudas de Erythrina velutina submetida ao estresse salino e aplicação de ácido salicílico. O delineamento utilizado foi em blocos casualizados, em esquema fatorial incompleto 5 x 5, gerados a partir da matriz Composto Central de Box com cinco níveis de condutividade elétrica da água de irrigação (CEa= 0,5; 1,74; 4,75; 7,76 e 9,0 dS m-1) e cinco doses de ácido salicílico (AS= 0,0; 0,29; 1,0; 1,71 e 2,0 mM L-1), com quatro repetições. Foram avaliadas as variáveis: altura da planta, número de folhas, diâmetro do caule, taxa de crescimento relativo e absoluto da altura e diâmetro do caule, massa seca de raiz, do caule, da parte aérea e total e o índice da qualidade de Dickson. Os dados foram submetidos à análise de variância pelo teste F, nos casos de significância foi realizada análise de regressão polinomial. A salinidade promove sérios danos ao crescimento das plantas de Erythrina velutina, sendo mais acentuado nos níveis crescentes de condutividade elétrica. A aplicação de ácido salicílico nas concentrações utilizadas não atenua os efeitos da salinidade

Physiological and Biochemical Changes in Immature Seeds of Tabebuia caraiba During Storage

Abstract Studies about the viability and vigor of seeds during storage, especially on the characterization of enzymatic changes, may increase the harvesting efficiency of immature seeds and guarantee their viability for a prolonged period. Therefore, this study aimed to evaluate the behavior of immature seeds of Tabebuia caraiba during storage. For this, thirty selected mother plants at the anthesis stage located in São João do Cariri and Sumé, Paraíba, Brazil were selected. Flowers of each tree were marked, and the fruits were harvested at 35, 42, and 49 days after anthesis (DAA) and characterized according to their maturation stages. The seeds from each maturation stage and city were packed in paper bags and stored in a refrigerator (6 ± 2 °C) for 360 days. The seed quality, seedling vigor, and enzymatic activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) were evaluated at the beginning of the storage period and intervals of 90 days. The seeds of T. caraiba harvested at 35, 42, and 49 DAA maintained high viability for 360 days of storage. T. caraiba seeds stored for 360 days withstood with high vigor when harvested at 42 DAA. The CAT, SOD, and POX activity was correlated to the deterioration process of the seeds under storage conditions

Physiological changes in Solanum lycopersicum L. in the presence of root-knot nematodes and salicylic acid

Nematodes of the genus Meloidogyne spp. are one of the tomato culture’s main pathogens. According to their soil infestation level, physiological changes may occur. Consequently, it is extremely important to employ given products to minimize their effect. A feasible option is the salicylic acid, a phytohormone that can induce into resistance due to its ability to increase the production level of some pathogenicity proteins. Therefore, the purpose hereof was to assess the effect of salicylic acid on the physiology of tomato plants subject to different populational densities of Meloidogyne javanica. The design employed was one of randomized blocks, in an incomplete factorial scheme, using the Box Central Compound (BCC) matrix with five nematode populational densities (PD) (0; 5815; 20000; 34184; and 40000 eggs per plant) and five salicylic acid doses (0.0; 0.29; 1.0; 1.71; and 2.0 mM), with four repetitions and two plants per experimental patch. The gas exchanges, fluorescence, and chlorophyll levels were evaluated 45 days after the transplant and soil infestation. The data were submitted for analysis of variance through the F test and, in the significance cases, the polynomial regression analysis was performed. For stomatal conductance, a greater reduction was seen at the PD of 21755 eggs per plant, a fact that might have decreased the liquid assimilation of CO2 and the efficiency of carboxylation. The salicylic acid (SA) affected the CO2 liquid assimilation and the efficiency of carboxylation. The infestation of M. javanica in tomato plants negatively affected the gas exchange and the chlorophyll levels because the SA application did not mitigate the negative effect thereof

FITOMASSA E CRESCIMENTO DE MANJERICÃO ROXO IRRIGADO COM ÁGUA SALINA SOB ADUBAÇÃO FOLIAR NITROGENADA

Basil is a species with high exploitation potential. However, its production in semiarid regions is compromised due to the salts contained in the soil and in the water used in irrigation, requiring the adoption of techniques that increase the tolerance of plants to salinity, such as nitrogen fertilization. Thus, this study aimed to evaluate the effect of leaf nitrogen fertilization on growth and phytomass allocation in purple basil plants under irrigation with saline water. The experiment was carried out in a randomized block design in an incomplete factorial scheme, with five levels of salinity (0.0; 0.81; 2.75; 4.69 and 5.50 dS m-1) and five levels of nitrogen (0.00; 58.58; 200.00; 341.42 and 400.00 mg L-1). Leaf succulence, sclerophilia index and shoot dry mass production, stem, leaf and root dry mass allocation, specific leaf area and leaf area ratio were evaluated. Foliar application of N attenuated the effects of salt stress on phytomass allocation, leaf succulence and shoot phytomass production index. N and salinity increased the specific leaf area and leaf area ratio in basil plants.O manjericão é uma espécie de elevado potencial de exploração. No entanto, sua produção em regiões semiáridas é comprometida decorrentes dos sais contidos no solo e na água utilizada na irrigação, sendo necessário a adoção de técnicas que aumente a tolerância das plantas a salinidade, como a fertilização com nitrogênio. Assim, objetivou-se avaliar o efeito da adubação nitrogenada foliar no crescimento e na alocação de fitomassa em plantas de manjericão roxo sob irrigação com águas salinas. O experimento foi realizado em delineamento de blocos casualizados em esquema fatorial incompleto, constando com cinco níveis de salinidade (0,0; 0,81; 2,75; 4,69 e 5,50 dS m-1) e cinco doses de nitrogênio (0,00; 58,58; 200,00; 341,42 e 400,00 mg L-1). Avaliou-se a suculência foliar, os índices de esclerofilia e de produção de fitomassa seca da parte aérea, alocação de fitomassa seca do caule, das folhas e da raiz, área foliar específica e razão de área foliar. A aplicação foliar de N atenuou os efeitos do estresse salino sobre a alocação de fitomassa, suculência foliar e no índice de produção de fitomassa da parte aérea. O N e a salinidade aumentou a área foliar específica e a razão de área foliar nas plantas de manjericão. Palavras-chave: estresse salino; Ocimum basilicum L.; nitrogênio.   Phytomass  and growth of purple basil irrigated with saline water under nitrogen foliar fertilization   ABSTRACT: Basil is a species with high exploitation potential. However, its production in semiarid regions is compromised due to the salts contained in the soil and in the water used in irrigation, requiring the adoption of techniques that increase the tolerance of plants to salinity, such as nitrogen fertilization. Thus, this study aimed to evaluate the effect of leaf nitrogen fertilization on growth and phytomass allocation in purple basil plants under irrigation with saline water. The experiment was carried out in a randomized block design in an incomplete factorial scheme, with five levels of salinity (0.0; 0.81; 2.75; 4.69 and 5.50 dS m-1) and five levels of nitrogen (0.00; 58.58; 200.00; 341.42 and 400.00 mg L-1). Leaf succulence, sclerophilia index and shoot dry mass production, stem, leaf and root dry mass allocation, specific leaf area and leaf area ratio were evaluated. Foliar application of N attenuated the effects of salt stress on phytomass allocation, leaf succulence and shoot phytomass production index. N and salinity increased the specific leaf area and leaf area ratio in basil plants. Keywords: salt stress, Ocimum basilicum L.; nitrogen

NITROGEN IMPROVES BIOMASS PRODUCTION AND CHLOROPHYLL SYNTHESIS IN BASIL PLANTS GROWN UNDER SALT STRESS

Basil (Ocimum basilicum L.), a medicinal and aromatic plant extensively cultivated in the Northeast region of Brazil, encounters growth challenges attributed to the salinity of irrigation water and soil. Nitrogen (N) is a crucial macronutrient employed to mitigate salt stress in plants. Therefore, this study aimed to evaluate the production of phytomass and chlorophyll synthesis in purple basil plants grown under salinity stress and nitrogen fertilization. The experiment was conducted in 2021 under protected environmental conditions at the Center for Agricultural Sciences, Universidade Federal Paraíba, Areia-PB, Brazil. Five levels of salt stress (0.0, 0.80, 2.75, 4.70, and 5.50 dS m-1) and five doses of N (0.00, 58.58, 200.00, 341.42, and 400.00 mg L-1) applied via foliar were studied. The results revealed that foliar fertilization with N increases plant tolerance to salt stress, promoting root fresh and dry mass accumulation at 294.96 and 205.36 mg L-1 and under ECw of 1.14 and 0.5 dS m-1, respectively. Applying 217.39 and 231.30 mg L-1 of N improves the production of stem dry biomass and the shoot/root ratio of basil plants subjected to salinity of 0.5 dS m-1. The electrical conductivity of irrigation water above 0.8 dS m-1 adversely affects biomass production. The salinity at 3.8 to 4.0 dS m-1 stimulated chlorophyll synthesis in purple basil plants. However, the foliar application of N proves to be a strategic approach to counteract these effects, resulting in increased total dry mass production and chlorophyll contents