Reduction of papaya rot (Phytophthora palmivora) with phosphite and Acibenzolar-S-Methyl in preharvest and postharvest

Abstract

The papaya fruit rot (Phytophthora palmivora) is responsible for significant losses. To reduce diseases, especially in areas with climate and humidity favorable to pathogens, are adopted chemical methods, which sometimes increase the cost of production and cause severe environmental impacts. Alternatively, there are products, such as, phosphites of potassium and acibenzolar-S-methyl (ASM) that might be efficient on disease control and less aggressive to environment. Phosphites of K and ASM were evaluated in this study on the control effectiveness of papaya fruit rot at different dosages in preharvest and postharvest. The severity and percentage of disease control were evaluated for each treatment. For the pre-harvest treatments (applied six days before harvest), the phosphite of K [240 g L-1 K 2 O, 340 g L-1 P 2 O 5 and 50 g L-1 (Reforce ® + Salicylic Acid)] at 3 or 6 mL L-1 significantly reduced disease severity, and, reduced fruit ripening. On postharvest application, ASM reduced disease severity.

Particularities of Fungicides and Factors Affecting Their Fate and Removal Efficacy: A Review

“…In addition, ASM induces the production of enzymes and phytoalexins when the plant is chemically, biologically, or physically stressed. However, ASM has been identified as phytotoxic, has been linked to production losses, and in some situations, may exacerbate other pest assaults [78]. Potassium phosphate (PP) is a salt that is applied in cultures as a foliar fertilizer.…”

“…PP is characterized by high mobility and solubility. As a result, harmful oomycetes are successfully controlled in different cultures, such as papaya, tomato, and potato [78,79]. Another salt, fosetyl-Al, is a worldwide broad-spectrum fungicide that is commonly used in horticulture.…”