Carica papaya, root rot, Phytopththora n. var. parasitica.
Objective: To test the efficiency of four chemical resistance inducers on Maradol papaya to reduce Phytopthora nicotianae var. parasitica infections in rainfed crops at Chontalpa, Tabasco, Mexico.
Design/methodology/approach: Three doses of four resistance inducers were tested on 60-day-old papaya plants in a greenhouse with a randomized design, with four replications and 10 plants as experimental plots. Three days after the inducers' application inoculations with mycelium discs were made, there were negative and positive control treatments to evaluating their efficiency by applying Abbott's formula.
Results: The four chemical inducers for resistance (sodium silicate (SS), potassium silicate (PS), potassium phosphite (PF) and acibenzolar-s-methyl (ASM)) were statistically different from the control (P < 0.0001**). The inducers SS 1 %, PS 1 %, FP 0.35 % and ASM 0.1 mM showed higher effectiveness (81.2, 75.9, 74.7 and 74.0 %).
Study limitations/implications: The retained effective concentrations were tested in a single application, and their durability is unknown, so this point should be broadened. however, it may be an alternative for repeated use after transplanting.
Findings/conclusions: Optimal concentrations of SS, PS, FP, and AMS, that respond against P. nicotianae var. parasitica infections can reduce damages in rainfed crops.