Evaluation of chemical resistance inducers in papaya Maradol against Phytophthora nicotianae var. parasitica

Abstract

Objective: To test the efficiency of four chemical resistance inducers in Maradol papaya, to reduce the infections of Phytophthora nicotianae var. parasitica in rainfed crops.

Design / methodology / approach: Three doses of each of four resistance inducers were tested in 60-day-old papaya plants in a greenhouse, in a completely randomized design, with four replications and 10 plants as experimental plot. The inoculations with mycelium discs were made three days after the application of the treatments with the inducers, including negative and positive control treatments to evaluate the efficiency applying the Abbott formula.

Results: The four chemical inducers (sodium silicate (SS), potassium silicate (SP), potassium phosphite (FP) and acibenzolar-s-methyl (ASM)) presented statistically differences to the negative control (P <0.0001 **). The inductors SS at 1%, SP 1%, FP 0.35% and ASM 0.1 mM showed greater effectiveness (81.2, 75.9, 74.7 and 74.0%, respectively).

Study limitations/implications: The effective concentrations retained were tested in a single application, and their durability is not known, so it should be expanded on this point, but it can be an alternative for repeated use after transplantation.

Findings/conclusions: the optimal concentrations of PS, SS, PF and ASM which respond against Phytopthora, which must to reduce damage in rainfed planting.