Water restriction as a strategy for growing Talinum fruticosum (L.) Juss. (Talinaceae)

Abstract

ABSTRACT Talinum fruticosum is a species confirmed to occur in the semi-arid region, considered an unconventional food plant with a high protein content and tolerant to temporary periods of water restriction. This study aimed to evaluate water deficit as a strategy for growing Talinum fruticosum, covering physiological and biochemical aspects. The experimental design adopted was entirely randomized, using six treatments and eight replications. The treatments were defined as water availability (WA) 0 (no water replenishment), 20, 40, 60, 80, and 100%, conducted in a greenhouse, with water replenishment every 7 days. After 21 days, the centesimal composition, water relations, gas exchange, and biochemical aspects were evaluated. The energy value of the dry biomass of T. fruticosum leaves was directly influenced by the water content in the soil, and the water deficit led to an increase in protein. Water restriction compromised the species' water status and performance, mainly limiting gas exchange by reducing the water content in the soil, compromising CO2 gain. It also led to increased biomolecules, with the highest contents seen in the treatments without water replacement (0%) and for 20% WA. Therefore, reducing the WA to 40% could be a strategy adopted to increase the protein content in the leaves of T. fruticosum, promoting an increase in the centesimal composition of proteins, a reduction in gas exchange, and an increase in the content of biomolecules.