Pathogenic variability of Moniliophthora perniciosa in three agroecological zones of the cacao region of Bahia, Brazil

Abstract

Resistant cacao genotypes are the best measure to control the Witches’ broom disease of cacao. To ensure efficiency, the pathogen variability in the cacao region of Bahia must be investigated. The pathogenic variability of Moniliophthora perniciosa inocula from nine municipalities was analyzed: Ilhéus, Floresta Azul and Jussari (agroecological zone Almada); Ipiaú, Itagibá and Jitaúna (agroecological zone Ipiaú), Camacan, Santa Luzia and Pau Brasil (agroecological zone Camacan), by inoculating progenies of Sca 6, ICS 1 and SIC 23 seedlings with 2 × 105 basidiospore.mL-1 of inocula and inoculum mixtures per agroecological zone, in a factorial 3 × 13 design, with 4 replications of 28 plants, in two seasons. Symptoms were assessed 60 days after inoculation. Pathogenic variability of inoculum in relation to the progeny performance was found; Ipiaú was the most aggressive and progeny ICS 1 the most susceptible. The mixtures of the agroecological zones Almada and Ipiaú were contrasting.