Agriculture in semi-arid regions faces significant challenges due to water scarcity and soil salinity, conditions exacerbated by inadequate irrigation practices and high evaporation rates. African mahogany (Khaya senegalensis), a species valued for its high-quality wood, holds potential for cultivation in these regions, provided that appropriate management practices are adopted. This study investigated the leaf transpiration response of African mahogany seedlings subjected to seven levels of irrigation water salinity, ranging from 0.5 to 5 dS·m⁻¹, using drainage lysimeters in an experimental field in Bahia. Data collection included measurements of stomatal conductance and photosynthetically active radiation (Qleaf) over a four-month period. The results showed a significant reduction in transpiration with increasing salinity, particularly above 3.5 dS·m⁻¹. Regression analyses highlighted a negative correlation between electrical conductivity and leaf transpiration, demonstrating the impact of water quality on plant physiology. These findings underscore the potential of African mahogany for cultivation in semi-arid regions, provided that efficient management practices are implemented to promote sustainable water use and mitigate the effects of salinity.

Salinity is one of the main environmental problems that negatively affect plant growth and metabolism, besides being one of the factors responsible for the decrease in the yield of crops, especially in arid and semiarid regions. Thus, the aim of this study was to evaluate the effects of soil salinity on the mineral nutrition of irrigated cowpea. The experiment was conducted in drainage lysimeters in a greenhouse, in a completely randomized design with seven treatments, one irrigated with freshwater (control) and six irrigated with saline water with different leaching fractions (5, 10, 15, 20, 30 and 40%) of the applied irrigation depth, with three replicates. The irrigation with saline water treatments did not affect significantly the contents of macronutrients and Na in the cowpea leaves, while the opposite behavior occurred with the micronutrients.

Transpiration, being the main water transport mechanism in plants, can be significantly impacted by the concentration of salts in the soil. This study aimed to investigate the influence of soil salinity and sun exposure on the transpiration of African mahogany seedlings in a semi-arid region. The research was conducted using drainage lysimeters, in which African mahogany (Khaya senegalensis) seedlings were grown, and different levels of salinity were applied to the irrigation water, ranging from 0.5 dS.m-1 to 5 dS.m-1 in seven different treatments. Each treatment was replicated three times, totaling 21 experimental units (plants), with the aim of optimizing the management of water resources in semi-arid environments. Relevant environmental data, such as photosynthetically active radiation (Qleaf), water potential and electrical conductivity, were collected directly in the field over four months after planting the seedlings in the lysimeters, located in an experimental field in Bahia. Perspiration assessment was performed using a steady-state diffusion porometer model LCpro-SD. The electrical conductivity of the irrigation water was monitored with a portable conductivity meter, being adjusted with the addition of sodium chloride (NaCl) to achieve different salinity levels. Regression analyzes were applied to understand how environmental variables influence the transpiration of mahogany plants. The results indicate that leaf transpiration decreases as the electrical conductivity of the water increases, especially in periods of water restriction. These findings provide valuable insights into the response of African mahogany seedlings to soil salinity and sun exposure, contributing to a better understanding and management of water resources in semi-arid regions.

This study aims at analyzing the behavior of young African mahogany plants in a saline environment, focusing on perceptions related to transpiration, photosynthetically active radiation and water potential. The experiment was conducted in drainage lysimeters, using different salinity levels of irrigation water. Environmental data, such as photosynthetically active radiation, water potential and electrical conductivity, were collected to investigate their influence on the transpiration of African mahogany plants. The research was carried out in an experimental field in the northeast region of Brazil, over a period of four months, with young African mahogany plants (Khaya senegalensis), using water with an electrical conductivity of 0.5 dS.m -1 (control treatment); 1.25 dS.m -1; 2 dS.m -1; 2.75 dS.m -1; 3.5 dS.m -1; 4.25 dS.m -1 and 5 dS.m -1 in a total of seven treatments, with three replications and 21 experimental units (plants). Plant transpiration was measured using a steady-state diffusion porometer. The electrical conductivity of the irrigation water was monitored using a portable conductivity meter. The results presented in the analyzes indicate a complex and interdependent relationship between leaf transpiration, photosynthetically active radiation and plant water potential. Leaf transpiration is influenced by variations in solar radiation, which plays a crucial role in regulating this process. It was observed that leaf transpiration is lower in the morning, from 7 to 9 am and in the late afternoon, from 5 to 6 pm, when incident solar radiation is at lower values.

Existem poucos estudos sobre o comportamento e as interações dos elementos meteorológicos sobre a evaporação ou a evapotranspiração que ocorrem em evaporímetros como do Irrigâmetro. Sendo assim, objetivou-se com esse estudo analisar os efeitos das interações dos elementos meteorológicos, temperatura máxima e mínima do ar, umidade relativa do ar, velocidade do vento e radiação solar, na evapotranspiração de referência estimada utilizando-se o Irrigâmetro, operando em diferentes alturas do nível de água no evaporatório. O estudo foi conduzido na área experimental do Instituto Federal da Bahia, localizado no município de Guanambi-BA. O experimento foi montado em delineamento inteiramente casualizado com sete tratamentos e três repetições. Os tratamentos consistiram de Irrigâmetros equipados individualmente com evaporatórios operando com níveis de água de 1 a 7 cm, tomados a partir de um nível de referência próprio do aparelho, totalizando 21 Irrigâmetros. Para avaliar os efeitos direto e indireto de cada variável meteorológica sobre a evapotranspiração de referência estimada pelo Irrigâmetro, utilizou-se a análise de trilha, que correlaciona a evapotranspiração, variável dependente, com os elementos meteorológicos, variáveis independentes. Em todos os níveis de água estudado o elemento meteorológico que apresentou maior correlação com a estimativa da evapotranspiração de referência foi a umidade relativa do ar, a radiação solar e a velocidade do vento, com valores iguais a 0,58; 0,53 e 0,49, respectivamente.