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

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

Produção de mudas de abobrinha sob estresse salino em diferentes ambientes e substratos

The interaction between agricultural environment and alternative substrates can attenuate salt stress in zucchini seedlings. Based on that, the objective of this work was to evaluate the production of zucchini seedlings irrigated with saline water and cultivated in different types of environments and substrates. The experimental design was completely randomized, using a split-split plots scheme, with the plot being the three cultivation environments (AM1= full sun; AM2= red screen with 50% shading; AM3= black screen with 50% shading), subplot the three substrates (SB1= biochar + soil; SB2= carbonized rice husk + soil; SB3= cattle manure + soil) and the subplot the two irrigation waters (AI1= 0.8 and AI2= 2.5 dS m-1), with four replications of twenty-five seeds. The variables analyzed were: emergence percentage (EP), emergence speed index (ESI), mean time of emergence (MTE), mean speed of emergence (MSE), stem diameter (SD), seedling height (SH) , root length (RL), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (TDM). The AM3 environment presented better conditions for the variables: EP, ESI and MSE. The environment AM2 presented better conditions for the variable MTE with the use of substrates SB2 and SB3 regardless of the salinity of the irrigation water. The SB3 substrate showed better growth conditions for the variables: SH, SD, SDM and TDM. The SB2 substrate provided better conditions for the variable RDM.A interação entre ambiência agrícola e substratos alternativos pode atenuar o estresse salino em mudas de abobrinha. Com base nisso, o objetivo deste trabalho foi avaliar a produção de mudas de abobrinha irrigadas com águas salinas e cultivadas em diferentes tipos de ambientes e substratos. O delineamento experimental foi o inteiramente casualizado, utilizando esquema de parcelas subsubdivididas, sendo a parcela os três ambientes de cultivo (AM1= pleno sol; AM2= telado vermelho com 50% de sombreamento; AM3= telado preto com 50% de sombreamento), a subparcela os três substratos (SB1= biocarvão + solo; SB2= casca de arroz carbonizado + solo, SB3= esterco bovino + solo) e a subsubparcela as duas águas de irrigação (AI1= 0,8 e AI2= 2,5 dS m-1),  com quatro repetições de vinte e cinco sementes. As variáveis analisadas foram: porcentagem de emergência (PE), índice de velocidade de emergência (IVE), tempo médio de emergência (TME), velocidade média de emergência (VME), diâmetro do caule (DC), altura de plântula (AP), comprimento da raiz (CR), massa seca da parte aérea (MSPA), massa seca da raiz (MSR) e massa seca total (MST). O ambiente AM3 apresentou melhores condições para as variáveis: PE, IVE e VME. Já o ambiente AM2 apresentou melhores condições para a variável TME com a utilização dos substratos SB2 e SB3 independente da salinidade da água de irrigação. O substrato SB3 apresentou melhores condições de crescimento para as variáveis: AP, DC, MSPA e MST. O substrato SB2 proporcionou melhores condições para a variável MSR

<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