Phytomass and quality of yellow passion fruit seedlings under salt stress and silicon fertilization

Abstract

The semiarid region of Northeastern Brazil is characterized by long drought periods, and the use of saline waters appears as an alternative for the expansion of irrigated areas. Associated with the use of these waters, silicon fertilization constitutes an important attenuator of salt stress. In this perspective, this study aimed to evaluate the phytomass production and quality of the passion fruit cultivar ‘Gigante Amarelo’ grown with saline water and silicon fertilization. The experiment was conducted in a plant nursery belonging to the Center of Agrifood Science and Technology, in the municipality of Pombal-PB. A completely randomized block design in a 5 x 5 factorial scheme was used, referring to five levels of electrical conductivity of the irrigation water (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five doses of silicon fertilization (0; 25; 50; 75, and 100 g of potassium silicate/plant), with four replications and two plants per plot. The phytomass accumulation (leaves, stem, and roots), as well as the total dry phytomass, shoot dry phytomass, root/shoot ratio, and the quality index of Dickson were evaluated. The data obtained were subjected to the F-test at 0.01 and 0.05 level of probability. The electrical conductivity of water from 0.3 dS m-1 caused the decrease of phytomass production in seedlings of the passion fruit cultivar ‘Gigante Amarelo’, although it is possible to produce good quality passion fruit seedlings with water salinity up to 3.1 dS m-1. The doses of silicon fertilization mitigated the effect of salt stress on the root/shoot ratio of plants of the passion fruit cultivar ‘Gigante Amarelo’.

Production of guava seedlings with increasing water salinity and nitrogenpotassium fertilizations

“…For C4, there was a linear reduction with the increase in irrigation water salinity, decreasing by 7.39% per unit increase in ECw, with a difference of 23.64% between the DMR values of seedlings irrigated with the highest and lowest salinity levels, indicating that C4 fertilization did not sufficiently reduce salt stress in the crop. The change in the osmotic potential of the soil solution possibly contributed to reducing DMR due to the increase in irrigation water salinity, because the restriction in root growth is considered a tolerance mechanism to reduce water uptake and, consequently, salt accumulation, decreasing toxicity (DINIZ et al, 2020).…”

Formation of guava seedlings under irrigation with water of different cationic natures and salicylic acid

“…However, when comparing plants cultivated under irrigation with water containing Mg 2+ (S5) to those subjected to the different cationic nature, no significant difference was observed. The reduction in biomass accumulation in plants subjected to ECw of 4.3 dS m -1 (S2, S3, S4, and S6) may be associated with changes in the partition of photoassimilates, with the displacement of energy, which is directed to growth for the activation and maintenance of metabolic activities associated with salinity tolerance mechanisms, such as the maintenance of membrane integrity and the regulation of transport and ionic distribution in various organs inside cells (DINIZ et al, 2020).…”

“…The decrease in biomass accumulation in plants subjected to salt stress also reflects the action of osmotic and ionic effects, which interferes with photosynthetic efficiency through energy expenditure to maintain membrane integrity, synthesis of organic solutes for osmoregulation and/or protection of macromolecules and regulation of ion transport and distribution, and, consequently, with plant growth and development, as observed in different crops, such as yellow passion fruit (DINIZ et al, 2020;LIMA et al, 2020), pomegranate (SOARES et al, 2021, and cherry tomatoes (ROQUE et al, 2022).…”