Ecofisiologia de Quiabeiro cultivado com águas salinas e adubação silicatada.

Abstract

The use of saline water or soils in the cultivation of vegetables can affect the physiological and growth characteristics of plants, limiting their production in places with low availability of fresh water, such as the semi-arid region of Northeast Brazil. An alternative to mitigate the deleterious effects of salt stress is the use of silicate fertilization, which increases tolerance and provides greater availability and absorption of nutrients by the plant. Thus, this work aimed to investigate the effects of saline levels and silicon doses on water relations, growth, photosynthetic pigments and fruit production of okra cv. Valença. The experiment was carried out under field conditions in the municipality of Pombal-PB. The experimental design was randomized blocks, in a 5 × 2 factorial scheme, with five levels of electrical conductivity of water - ECw (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and two doses of silicate fertilization (100 and 200 g of silicon per plant) with four replications. Water salinity above 0.3 dS m-1 inhibited the growth in leaf area, plant height, stem diameter and phytomass accumulation of okra plants cv. Valencia. Water salinity up to 1.0 and 2.1 dS m-1 increased the water potential in the leaf blade and the diameter of okra fruits, respectively. Fertilization with a dose of 100 g per plant of silicon increased the levels of chlorophyll b, carotenoids and electrolyte leakage in okra plants cv. Valença. The interaction between the levels of electrical conductivity of water and doses of silicon influenced the levels of chlorophyll b and carotenoids and the extravasation of electrolytes in the leaf blade of okra plants cv. Valença.