Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress

Abstract

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.

Exogenous application of salicylic acid induces salinity tolerance in eggplant seedlings

“…Because it causes ionic imbalance and consequent toxicity, in addition to favoring oxidative stress, physiological drought and nutrient deficiency in the plant, salinity compromises morphological and physiological yields (Zörb et al, 2019). Under conditions of tolerance to salt stress, plants tend to reduce reactive oxygen species, maintaining physiological and biochemical processes, as well as plant growth and production, thus avoiding enzyme inactivation, lack of nutrients, ionic toxicity in tissues and, consequently, cell death (Fernandes et al, 2022).…”