Irrigação Com Água Salina E Uso De Substratos Na Cultura Do Feijão-Caupi

Abstract

Objetivou-se avaliar a interação entre diferentes níveis salinos e substratos sob o crescimento inicial, o acúmulo de biomassa e as trocas gasosas da cultura do feijão-caupi. O experimento foi conduzido na área experimental da Universidade Federal do Ceará, Fortaleza, Ceará. O delineamento utilizado foi inteiramente casualizado em esquema fatorial (5 x 2), com quatro repetições. Os tratamentos foram constituídos por substratos inseridos ao solo (T1- biocarvão + solo na proporção 1:1; T2- solo (testemunha); T3- adubação mineral; T4- casca de arroz carbonizada + carnaúba + solo na proporção 2:1:1 e S5- casca de arroz carbonizada + solo na proporção 1:1), e duas águas de irrigação (1,0 e 4,0 dS m-1). Aos 40 dias após a semeadura (DAS) foram avaliados: número de folhas (NF), altura de planta (AP), diâmetro do caule (DC), área foliar (AF), massa seca da parte aérea (MSPA) e total (MST), fotossíntese (A), transpiração (E) e condutância estomática (gs). A água de alta salinidade afetou negativamente a AP, DC, MSPA e a gs das plantas. Os tratamentos T4 e T5 promoveram maior NF e A quando combinado com água não salina. Os tratamentos T4 e T5 proporcionaram maiores valores de gs e E. Palavras-chave: Vigna unguiculata L. Walp; salinidade; adubação. Influence of saline stress and fertilizers on caupi bean crop ABSTRACT: The objective was to evaluate the effects of salt stress on the initial growth, on the accumulation of biomass and on the gas exchange of the cowpea culture submitted to different substrates. The experiment was conducted in the experimental area of the Federal University of Ceará, Fortaleza, Ceará. The design used was completely randomized in a factorial scheme (5 x 2), with four replications. The treatments consisted of substrates inserted in the soil (T1- biochar + soil in the proportion 1: 1; T2- soil (control); T3- mineral fertilization; T4- carbonized rice husk + carnauba + soil in the proportion 2: 1: 1 and S5- carbonized rice husk + soil in a 1: 1 ratio), and two irrigation waters (1.0 and 4.0 dS m-1). At 40 days after sowing (DAS), the following were evaluated: number of leaves (NF), plant height (AP), stem diameter (DC), leaf area (AF), shoot dry matter (MSPA) and total (MST), photosynthesis (A), transpiration (E) and stomatal conductance (gs). High salinity water negatively affected AP, DC, MSPA and plant gas. The treatments T4 and T5 promoted greater NF and A when combined with non-saline water. The treatments T4 and T5 provided higher values of gs and E. Keywords: Vigna unguiculata L. Walp; salinity; fertilization.

Salt stress and leaching fraction in cowpea culture

“…One of the main effects of salinity on plant growth is related to the reduction in development, caused by the decrease in the water potential of the soil solution at a level below the limit of water assimilation by the root zone, limiting cellular enlargement, taking into account that the cell pressure potential tends to equalize with that of the soil (TAIZ et al, 2017). Similar trend to this study for irrigation with higher salinity water was verified by Sousa et al (2021) in bean culture.…”

“…However, the smaller leaf area when irrigated with water of higher salinity corroborates with Pereira Filho et al (2020), when affirming that the negative influence of salinity on leaf area may be related to the action of the osmotic part that hinders the absorption of water by the plant, as well as the toxicity caused by the excess of certain ions. Similarly, Sousa et al (2021) observed a reduction in the leaf area of the bean crop when irrigated with increasing saline water at a leaching fraction of 15%. For water with a higher salinity, there was a greater reduction in leaf area.…”

“…is a crop originally from Africa and presents great importance for human nutrition, being one of the main sources of protein, besides its high level in energy, vitamins and minerals, being among the main subsistence crops in the Brazilian semiarid region (OLIVEIRA et al, 2017;FREIRE FILHO et al, 2011). In the Northeast region, the higher demand for irrigation water has led to the use of most of the available water sources, thus, the use of lower quality water such as brackish water at some point in the crop cycle is necessary (SOUSA et al, 2021).…”

“…The excess of salts reduces the availability of water for plants that modifies both metabolic and morphological structures, causing a reduction in germination and emergence of seeds and can compromise physiological functions, resulting in disturbances in water relations, changes in the absorption and utilization of nutrients (CEITA et al, 2020;MAGALHÃES et al, 2021;SOUSA et al, 2021).…”

Salicylic acid does not mitigate salt stress on the morphophysiology and production of hydroponic melon

“…Summary of the analysis of variance for intercellular electrolyte leakage (IEL), shoot dry biomass (SDB), and total dry biomass (TDB) of 'Gaúcho' melon cultivated in hydroponic system with different levels of electrical conductivity of nutrient solution (ECns) and exogenous application of salicylic acid (SA), 74 days after transplanting. (Sousa et al, 2021). Sousa (2015) evaluated the cultivation of mini-watermelon cv.…”