Heterogeneity of peach rust disease progress within the tree canopy

Dispersal gradient of M. fructicola conidia from peach orchard to an open field

“…The inoculum production at harvest does not over time; instead a high amount of inoculum is produced on ripe fruit and then it decreases, as the fruit are taken from the trees. Our results indicate that the primary brown rot inoculum is produced in the orchard and that external inoculum sources have small epidemiological importance, in agreement with previous studies (Nesi et al, 2014;Villarino et al, 2010). This particularly important in Brazil, as peach and plum production is staggered, with early, intermediate, and late cycle cultivars (Alves et al, 2017).…”

“…Instead, in Brazil, fruit infections originate mainly from inoculum produced on twig cankers (Keske et al, 2011) although it can also originate from closed rot fruit, thinned and mummified fruit (Hong et al, 1997;. For perennial crops such as peach and apple, both the primary and secondary inoculum of pathogens are produced within the orchard, while external sources, in general, have less epidemiological relevance (Hamada et al, 2019;Nesi et al, 2014).…”

Peach Rust (Transchelia spp.)

“…Path of T. discolor between peach and poppy anemone, an alternate host: a) aeciospore infects peach twig; b) urediniospores move from twig to leaf; c) urediniospores move from leaf to fruit; d) other urediniospores on leaf develop teliospores, which are overwintering structures; e) overwintering structures produce basidiospores, which infect the alternate host; and f ) aeciospores are produced on poppy anemone, which restart the cycle. Credits: Image adapted from photos by M. Knight and Z. Evenor rust outbreaks are affected by many factors, such as the source of inoculum, the cultivar, weather, tree spacing, and cultural management (Nesi et al 2014;Kowata et al 2011).…”