Growth of yellow passion-fruit seedlings in different substrates under salt stress

Salt stress can negatively affect the development of seedlings. However, the use of alternative substrates can mitigate these effects. The present study aimed to evaluate the growth of yellow passion-fruit seedlings in response to irrigation with saline water grown on different substrates. The experiment was developed at the University of International Integration of Afro-Brazilian Lusofonia, Redenção, Ceará, Brazil. The experimental design was entirely randomized, in a 2 × 5 factorial arrangement, composed of two levels of electrical conductivity of the irrigation water (0.3 and 3.0 dS m-1) and five substrate types (S1 = soil; S2 = sand, sandy soil, and bovine manure – 1:1:1; S3 = sand, sandy soil, and carbonized rice husk – 1:1:1; S4 = sand, sandy soil, and biochar – 1:1:1; S5 = sand, sandy soil, and vegetal ash – 1:1:1), with five replications. The S2 substrate containing sand, sandy soil, and bovine manure promoted higher performance of seedling height, stem diameter, shoot dry mass, root dry mass, and total dry mass associated with low salinity water. The S2 substrate was more efficient for leaf area, while S4 substrate was more efficient for number of leaves, root length, and pH. The S1 and S2 substrates presented higher electrical conductivity of the saturation extract using water of higher conductivity.Salt stress can negatively affect the development of seedlings. However, the use of alternative substrates can mitigate these effects. The present study aimed to evaluate the growth of yellow passion-fruit seedlings in response to irrigation with saline water grown on different substrates. The experiment was developed at the University of International Integration of Afro-Brazilian Lusofonia, Redenção, Ceará, Brazil. The experimental design was entirely randomized, in a 2 × 5 factorial arrangement, composed of two levels of electrical conductivity of the irrigation water (0.3 and 3.0 dS m-1) and five substrate types (S1 = soil; S2 = sand, sandy soil, and bovine manure – 1:1:1; S3 = sand, sandy soil, and carbonized rice husk – 1:1:1; S4 = sand, sandy soil, and biochar – 1:1:1; S5 = sand, sandy soil, and vegetal ash – 1:1:1), with five replications. The S2 substrate containing sand, sandy soil, and bovine manure promoted higher performance of seedling height, stem diameter, shoot dry mass, root dry mass, and total dry mass associated with low salinity water. The S2 substrate was more efficient for leaf area, while S4 substrate was more efficient for number of leaves, root length, and pH. The S1 and S2 substrates presented higher electrical conductivity of the saturation extract using water of higher conductivity

Potential of Brackish Groundwater for Different Biosaline Agriculture Systems in the Brazilian Semi-Arid Region

The objective of this research was to define the potential of brackish groundwater for 15 systems of biosaline agriculture in a representative area of the Brazilian semi-arid region. The study was conducted using a database of the State of Ceará, with 6284 wells having brackish water (EC ≥ 0.8 dS m−1 and discharge rate ≥ 0.5 m3 h−1). Our results show that the potential of brackish groundwater resources depends on the set of data: (i) production system (crop salt tolerance and water demand) and (ii) water source (salinity and well discharge rate). The joint analysis of these data shows that plant production systems with lesser water requirements, even with moderate tolerance levels to salt stress, present better results than more tolerant species, including halophytes and coconut orchards. About 41, 43, 58, 69, and 82% of wells have enough discharge rates to irrigate forage cactus (1.0 ha), sorghum (1.0 ha with supplemental irrigation), hydroponic cultivation, cashew seedlings, and coconut seedlings, respectively, without restrictions in terms of salinity. Otherwise, 65.8 and 71.2% of wells do not have enough water yield to irrigate an area of 1.0 ha with halophytes and coconut palm trees, respectively, butmore than 98.3 and 90.7% do not reach the water salinity threshold for these crops. Our study also indicates the need for diversification and use of multiple systems on farms (intercropping, association of fish/shrimp with plants), to reach the sustainability of biosaline agriculture in tropical drylands, especially for family farming

Ambiência agrícola e estresse salino na produção de mudas de maracujazeiro amarelo

The objective was to evaluate the initial growth and gas exchange of yellow passion fruit seedlings irrigated with saline water under different environments. The experiment was conducted of the University of International Integration of Afro-Brazilian Lusophony, Redenção-CE. The experimental design used was entirely randomized, in factor arrangement 4 x 2, referring to four environments with different shade screens (black screen; whitescreen; red screen; all with 50% shading; and full sun) and the values of electrical conductivity of irrigationwater (0.3 and 3.0 dS m-1), with five repetitions. The following variables were evaluated: number of leaves, plant height, leaf area, photosynthesis, transpiration, stomach conductance, instantaneous water use efficiency, electrical conductivity of the saturation extract and soil pH. The environment with black screen provides greater performance in leaf area, plant height and root length and was more efficient for the production of dry mass of the aerial part and the root of passion fruit seedlings in both irrigation waters. The red screen environment stimulates greater photosynthesis, transpiration, stomach conductance and chlorophyll in passion fruit seedlings irrigated with low salinity water, while the black screen mitigated saline stress for these variables. The full sun environment provided greater instantaneous water use efficiency in passion fruit seedlings for treatment with low salinity water and the black screen environment with high salinity water.O objetivo foi avaliar o crescimento inicial e as trocas gasosas de mudas de maracujá-amarelo irrigadas com água salina em diferentes ambientes. O experimento foi conduzido na Universidade de Integração Internacional da Lusofonia Afro-Brasileira, Redenção-CE. O delineamento experimental utilizado foi inteiramente casualizado, em arranjo fatorial 4 x 2, referente a quatro ambientes com telas de diferentes tonalidades (tela preta; tela branca; tela vermelha; todas com 50% de sombreamento; e pleno sol) e os valores de condutividade elétrica da água de irrigação (0,3 e 3,0 dS m-1), com cinco repetições. Foram avaliadas as seguintes variáveis: número de folhas, altura da planta, área foliar, fotossíntese, transpiração, condutância estomática, eficiência instantânea do uso da água, condutividade elétrica do extrato de saturação e pH do solo. O ambiente com tela preta oferece maior desempenho em área foliar, altura de planta e comprimento de raiz e foi mais eficiente para a produção de massa seca da parte aérea e raiz de mudas de maracujá em ambas as águas de irrigação. O ambiente da tela vermelha estimula maior fotossíntese, transpiração, condutância estomática e clorofila em mudas de maracujá irrigadas com água de baixa salinidade, enquanto a tela preta mitigou o estresse salino para essas variáveis. O ambiente a pleno sol proporcionou maior eficiência no uso instantâneo da água em mudas de maracujá para tratamento com água de baixa salinidade e o ambiente tela preta com água de alta salinidade. altura de planta e comprimento de raiz e foi mais eficiente para a produção de massa seca da parte aérea e raiz de mudas de maracujá em ambas as águas de irrigação. O ambiente da tela vermelha estimula maior fotossíntese, transpiração, condutância estomática e clorofila em mudas de maracujá irrigadas com água de baixa salinidade, enquanto a tela preta mitigou o estresse salino para essas variáveis. O ambiente a pleno sol proporcionou maior eficiência no uso instantâneo da água em mudas de maracujá para tratamento com água de baixa salinidade e o ambiente tela preta com água de alta salinidade. altura de planta e comprimento de raiz e foi mais eficiente para a produção de massa seca da parte aérea e raiz de mudas de maracujá em ambas as águas de irrigação. O ambiente da tela vermelha estimula maior fotossíntese, transpiração, condutância estomática e clorofila em mudas de maracujá irrigadas com água de baixa salinidade, enquanto a tela preta mitigou o estresse salino para essas variáveis. O ambiente a pleno sol proporcionou maior eficiência no uso instantâneo da água em mudas de maracujá para tratamento com água de baixa salinidade e o ambiente tela preta com água de alta salinidade. enquanto a tela preta atenua o estresse salino para essas variáveis. O ambiente a pleno sol proporcionou maior eficiência no uso instantâneo da água em mudas de maracujá para tratamento com água de baixa salinidade e o ambiente tela preta com água de alta salinidade. enquanto a tela preta atenua o estresse salino para essas variáveis. O ambiente a pleno sol proporcionou maior eficiência no uso instantâneo da água em mudas de maracujá para tratamento com água de baixa salinidade e o ambiente tela preta com água de alta salinidade

<i>Bacillus aryabhattai</i> Mitigates the Effects of Salt and Water Stress on the Agronomic Performance of Maize under an Agroecological System

The use of plant-growth-promoting rhizobacteria (PGPR) can be one option for mitigating the impact of abiotic constraints on different cropping systems in the tropical semi-arid region. Studies suggest that these bacteria have mechanisms to mitigate the effects of water stress and to promote more significant growth in plant species. These mechanisms involve phenotypic changes in growth, water conservation, plant cell protection, and damage restoration through the integration of phytohormone modulation, stress-induced enzyme apparatus, and metabolites. The aim of this study was to evaluate the growth, leaf gas exchange, and yield in maize (Zea mays L.—BRS Caatingueiro) inoculated with Bacillus aryabhattai and subjected to water and salt stress. The experiment followed a randomised block design, in a split-plot arrangement, with six repetitions. The plots comprised two levels of electrical conductivity of the irrigation water (0.3 dS m−1 and 3.0 dS m−1); the subplots consisted of three irrigation depths (50%, 75%, and 100% of the crop evapotranspiration (ETc)); while the sub-subplots included the presence or absence of B. aryabhattai inoculant. A water deficit of 50% of the ETc resulted in the principal negative effects on growth, reducing the leaf area and stem diameter. The use of B. aryabhattai mitigated salt stress and promoted better leaf gas exchange by increasing the CO2 assimilation rate, stomatal conductance, and internal CO2 concentration. However, irrigation with brackish water (3.0 dS m−1) reduced the instantaneous water-use efficiency of the maize. Our results showed that inoculation wiht PGPR mitigates the effect of abiotic stress (salt and water) in maize plants, making it an option in regions with a scarcity of low-salinity water