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.

The state of Paraíba, specifically in the alto sertão of Paraíba, is characterized by the spatial and temporal variability of rainfall, of temperature and evapotranspiration, coming from the semi-arid climate that is inserted in the region, and yet, the performance of different meteorological systems. The objective was to quantify the rainfall, temperature and reference evaporation (mm/ month and mm/year) comprised in the experimental period between 2016 to 2020, in the municipality of Catolé do Rocha-PB, in order to determine the history of the rainy and dry season, and thus, minimize agricultural production losses due to environmental factors. The daily rainfall, temperature and reference evaporation data were obtained by means of a rain gauge and the indirect method of the class A tank, respectively. The rainfall (mm year-1) was analyzed by the nonparametric Friedman test, the Conover test and reference evaporation (mm year-1) applied the parametric test of the ANAVA and the test of Tukey HSD. Both parametric and non-parametric tests were analyzed by Real Statistics. Temperature data was compiled from the website (www.inmet.gov.br) in order to control, statically collecting and decision-making in the process of building scientific knowledge regarding meteorological data (climate - Temperature). Were also analyzed pearson's correlation matrices and elementary principal components analysis for the rainfall variables, Eto and Temperature in the studied experimental period. Were also studied the principal component analysis between the years 2016 to 2020 and its significance by the t test. The average reference evaporation between 2016 and 2020 was 2.1 times greater than rainfall. Mean rainfall and reference evaporation in Catolé do Rocha-PB between 2016 and 2020 were 827 mm ano-1 and 1704 mm year-1 and are compatible with historical averages of 800 mm year-1 and 1700 mm year-1, respectively. Inglesa.

O uso de silício associado com matéria orgânica é uma alternativa na fruticultura que está associada aos efeitos no crescimento, nas características físico-químicos dos frutos e na produção, visando atender padrões de qualidade exigidos para o consumo in natura ou para o processamento. Esse estudo visa avaliar a influenciam do silício associado a adubação orgânica nos atributos físico-químicos em frutos de frutos de maracujazeiro amarelo cultivado no semiárido Brasil. Os tratamentos foram arranjados em blocos ao acaso, com quatro repetições e quatro plantas por parcela, usando o esquema fatorial 5 x 2, relativo às doses de silício de 0, 45, 90, 135 e 180 kg ha-1 e dois níveis de matéria orgânica (valor existente no solo 1,2% e elevar o teor para 4%). As variáveis físico-químicas avaliadas referiram-se à espessura da polpa do fruto (ESPF), espessura da casca do fruto (ESCF), volume da polpa sem sementes (VPSS), número de sementes por fruto (NSF), pH e sólidos solúveis (SS). Os dados foram submetidos à análise de variância pelo teste F (p<0,05) e regressões. A interação silício e adubação orgânica influenciaram as características físico-químicas dos frutos de maracujá-amarelo. Os frutos de maracujá-amarelo colhidos apresentam características físico-químicas que podem ser aceitas tanto na indústria quanto no mercado in natura.

Several semiarid regions have soils with low organic matter content and adverse climates. Organic and silicon fertilization can benefit plants physiologically, thus contributing to increasing the yield of agricultural crops. The present study aimed to evaluate the gas exchanges, cell water status and yield of yellow passion fruit under organic and silicon fertilization and semiarid conditions. The field experiment used a randomized block design, in a 2 × 5 factorial scheme, consisting of two soil organic matter levels (no addition and 4 %) and five silicon doses (0, 27, 54, 81 and 108 g plant^-1), with four replications and six plants per plot. The gas exchanges, cell water status and yield of yellow passion fruits were assessed. Regardless of the applied dose, silicon affected certain aspects related to gas exchanges and cell water status. Applying 108 g of silicon per plant results in higher fruit yields, and increasing the soil organic matter to 4 % ensures a better cell water status and yield of yellow passion fruit under semiarid conditions.

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.