| Abstrakt: |
Cashew is a fruit species of great economic importance in Brazil, especially in its Northeast region. However, abiotic factors such as water and soil salinity stand out as limiting parameters for this crop, affecting all phases of development as well as physiological and biochemical processes. In this scenario, the use of products to mitigate such damage becomes a necessary practice, with silicon and potassium being viable alternatives. From this perspective, the present study aimed to evaluate the photochemical efficiency of cashew rootstocks subjected to water salinity and foliar application of potassium silicate. A randomized block design arranged in a 5x5 factorial with four replications and two plants per plot was used in the experiment. Treatments consisted of different levels of irrigation water electrical conductivity - ECw (0.3, 1, 1.7, 2.4, and 3.1 dS m-1) and potassium silicate concentrations (0, 250, 500, 750, and 1000 mg L-1) supplied via foliar application. Irrigation water salinity levels from 2.1 dS m-1 reduce the photochemical efficiency of photosystem II by at least 10%, consequently affecting the photosynthetic apparatus of cashew plants 70 days after sowing. The potassium silicate concentration of 250 mg L-1 increases the quantum yield of cashew plants under salt stress conditions. [ABSTRACT FROM AUTHOR] |
