Inorganic salts in the postharvest control of Penicillium digitatum (Pers.) Sacc. in orange

Abstract

The objective of this research was to evaluate the effect of treating oranges with potassium chloride (KCl), potassium hydroxide (KOH) and potassium silicate (K2O3Si) for green mold caused by Penicillium digitatum. The experimental design was completely randomized with five treatments and four replications, each with twenty fruits. For the experiment, the fruits were washed, superficially disinfected and pierced with a needle (2–3 mm deep). After 24 hours, the fruits were treated with inorganic salts or distilled water (control) and, 2 hours later, inoculated with 15 μL of P. digitatum spore suspension. Green mold incidence, rate of lesion expansion, lesion size and sporulation area were evaluated at 96, 120 and 245 ha. At 245 hours after inoculation (hai), the KOH and K2O3Si (50 g.L-1) treatments were the most effective, affecting all evaluated variables and reducing the disease incidence by 80% and 36%, respectively, compared to the control. However, the KOH treatment caused wrinkling and dehydrated the peel, affecting the visual quality of the fruits. In conclusion, among the tested inorganic salts, the K2O3Si treatment (50 g.L-1) reduced the green mold in the citrus without negatively effecting fruit appearance, which indicates that this treatment is an option as a complementary measure to manage the disease.

Keywords

• Bolor verde
• Citricultura
• Controle de podridões
• Minerais
• Silício