Does the sunblock alleviate abiotic stress in mango trees grown in the tropical semiarid?

Mango is the most exported fruit of Brazil, especially grown in São Francisco Valley (tropical semiarid) where there is high temperatures and low air humidity, a condition that can cause stress to plants. Thus, the current study aimed to evaluate the effectiveness of different sunblocks to alleviate the abiotic stress of “Palmer” mango trees grown in a semiarid environment. The experimental design consisted of randomised blocks with six treatments, four repetitions and three plants per plot. The treatments consisted of different strategies of sunblocks as follows: (T1) control (no sunblock); (T2) calcium carbonate (50 g · L⁻¹); (T3) sunblock (5 mL · L⁻¹); (T4) sunblock (5 mL · L⁻¹) + calcium carbonate (50 g · L⁻¹); (T5) sunblock (5 mL · L⁻¹) + sunblock silicon concentrated (20 mL · L⁻¹) and (T6) sunblock (20 mL · L⁻¹). The results indicate a clear action of sunblock in attenuating the abiotic stress of mango, with a persistent effect with time elapsing, considering the evaluated interval. The sunblock clearly promotes a differentiated leaf coverage pattern, protecting the photosynthetic apparatus and increasing its performance and consequently improving the production of plant reserves. The use of calcium carbonate individually promotes a very short protective effect, without positive reflexes after a few days of application. Mango fruit yield is affected by the sunblock with an increase of 4.2 t · ha⁻¹ from the treatment with sunblock (20 mL · L⁻¹) in relation to the control treatment.