Overwintering of Monilinia spp. on Mummified Stone Fruit

Mummies were evaluated over the course of four growing seasons to ensure they are source of primary inoculum. The percentage of mummies with presence of conidia and its viability were determined in tree and ground mummies. The number of conidia and its germination were also quantified. Fruit mummies with Monilinia spp. were consistently detected on tree mummies in all studied orchards and growing seasons. However, the percentage of viable mummies over the same sampling periods decreased, and in most cases, it was 0% by October. The percentage of ground mummies with Monilinia spp. was lower and less viable in comparison with tree mummies, tending to decrease faster. The number of overwintering conidia in tree mummies decreased smoothly from 1x10(6) to 1x10(4) conidia/mummy between April and September. On the other hand, the number of conidia in ground mummies rapidly decreased to 0 conidia/mummy at around May-July. The profiles for the percentage of conidia germinated were similar in all cases. The information obtained from this study is a step forward to understanding the epidemiology of Monilinia spp., a useful tool to manage disease development.