In the Brazilian semi-arid region, the production of passion fruit seedlings often faces challenges such as irrigation with saline water. However, silicate fertilization stands out as an effective solution for mitigating the salinity effects. This study aimed to evaluate the use of silicon as a salt stress mitigator in yellow passion fruit seedlings, under greenhouse conditions. The experimental design was completely randomized, with six replications, in a 5 × 2 factorial scheme, referring to five silicon doses (0, 0.25, 0.50, 0.75 and 1.0 g plant^-1) and two electrical conductivity levels of the irrigation water (1.2 and 3.5 dS m^-1). Variables related to plant growth, biomass and physiology were analyzed. Silicon doses between 0.50 and 0.60 g plant^-1 provided the best results for the passion fruit seedlings’ growth, water status and physiology, both under lower (1.2 dS m^-1) and higher (3.5 dS m^-1) salinity conditions. The silicon strengthened the plants and improved water absorption, mitigating the negative effects of salinity on the yellow passion fruit.

Silicon has emerged as a beneficial element in mitigating water deficit in various crops, although the underlying mechanisms still require further investigation. This study evaluated the foliar content of nutrients (N, P, K, and Ca) and proline, antioxidant activity, growth, water use efficiency, and yield of cowpea cultivars subjected to two irrigation depths (50% and 100% of crop evapotranspiration) and a foliar application of silicon (orthosilicic acid). A field experiment was conducted in a split-plot scheme using the randomized block design with four replications in a semi-arid region of northeastern Brazil. Silicon supplementation increased the foliar contents of N, P, and Ca; stimulated proline synthesis; and enhanced the activity of the SOD, CAT, and APX enzymes. These changes promoted growth, improved water use efficiency, and increased crop yield. The results indicate that foliar silicon application mitigates the effects of water deficit in cowpea plants while enhancing crop performance under full irrigation (100% of crop evapotranspiration), leading to higher yields even under favorable water conditions.

Environmental filtering has been defined as the effect of environmental gradients on species in a plant community and can be the dominant driver of community assembly. Here, we evaluate the relationship between plant communities and the environment in the Restinga vegetation. For this, we measured 11 functional traits of plant species present along transects covering a marked edaphic environmental gradient. This gradient was characterized through Principal Component Analysis of soil characteristics. The relationships between the edaphic gradient and functional traits were evaluated using linear models. Finally, we compared the contributions of species turnover and intraspecific variation to among-site variation in functional traits. The gradients associated with soil nutrients (PCA axis 1) and soil acidity and organic matter (PCA axis 2) were then used to test the observed changes in community composition and were significant predictors of the distribution of water potential, leaf dry matter content and K content, height and chlorophyll index. Decomposing the total variation in the distribution of functional traits between species turnover and intraspecific variation revealed that species turnover explains a greater proportion of the observed variation. We conclude that community assembly is strongly limited by environmental filters and mediated by functional traits at the species level.

Silicon (Si) is a beneficial element that alleviates the adverse effects of salinity in plants. Despite extensive evidence of Si-mediated stress alleviation in other crops, information for tropical fruit species such as Passiflora edulis remains limited, especially regarding the efficiency of different application methods. This study evaluated two yellow passion fruit cultivars (BRS Sol do Cerrado and BRS Gigante Amarelo) at the seedling stage under five management conditions: irrigation with 1.2 dS m⁻¹ water (control), 4.0 dS m⁻¹ water (salt stress), and salt stress combined with Si applied via soil, foliar spray, or both (soil + foliar), using silicic acid as the Si source. The experiment was conducted in a completely randomized design in a 2 × 5 factorial arrangement with five replicates. High salinity decreased foliar nutrient concentrations, gas exchange, and seedling quality, whereas Si mitigated these effects depending on the application method and cultivar. Combined soil and foliar application increased nutrient contents, biomass, and the Dickson Quality Index, especially in BRS Gigante Amarelo. These findings provide new insights into Si management for P. edulis and offer practical implications for improving nutrient balance, growth, and seedling performance under saline conditions.

Os solos nas regiões semiáridas geralmente apresentam baixos níveis de matéria orgânica, devido a factores pedogenéticos do solo, e é notável que a aplicação de fertilizantes orgânicos ao solo aumenta a sua fertilidade e o rendimento das culturas. Assim, o objetivo desta pesquisa foi avaliar os efeitos da adubação orgânica do solo nos atributos químicos de um Neossolo Flúvico e na produtividade do quiabeiro em dois ciclos de cultivo. Os tratamentos foram distribuídos em blocos casualizados no esquema fatorial 5 x 2, referente a cinco doses de esterco bovino com relação C/N de 18:1 para aumentar o teor de matéria orgânica no solo de 1,8% para 2,8; 3,8; 4,8 e 5,8% e dois ciclos de cultivo (1º e 2º ciclos) com quatro repetições. As variáveis ​​analisadas foram pH do solo, P, Ca2+, Mg2+, K+ no solo, S.O.M e produtividade de quiabo. Os resultados foram submetidos à análise de variância por meio do teste F para verificar a homogeneidade entre os resíduos. Posteriormente, foi realizada análise conjunta para diagnosticar efeitos significativos por meio do teste F e regressões lineares e polinomiais foram aplicadas para desdobrar o S.O.M em um ciclo. A adubação orgânica com esterco bovino aumentou os teores de P, K+, Ca2+, Mg2+, Na+ e matéria orgânica do solo (S.O.M) e a produtividade dos frutos comerciais de quiabo.