English names: Brown rot, Twig canker
Nordic names: Frugtskimmel (DK), Fruktmögel (FI)
Major host plants
Monilinia fructicola attacks especially fruit trees within the genus , however apple and pear may also be attacked. Major hosts are Prunus avium (sweet cherry), Prunus domestica (plum), Prunus persica (peach), Prunus armeniaca (apricot), Prunus cerasus (sour cherry) and Prunus dulcis (almond). The fungus can be found on other plants within Rosaceae as Chaneomeles, Crataegus, Cydonia and Eriobotrya.
Symptoms from Monilinia fructicola cannot be distinguished from symptoms of two common Monilinia species and should therefore be examined in a laboratory. Both M. fructicola and M. laxa produce grey coloured conidial pustules, while the third species M. fructigena produces buff to beige coloured conidia.
M. fructicola attacks all parts of the trees and at all stages. Infection with the fungus is particularly visible in the flowering stage of trees and towards fruit ripening, due to the obvious symptoms. Flowers turn rapidly brown and die. Leaves wither and the stem develops cankers with brown sunken areas, often covered with gum. Fruits can be attacked at all stages of development and powdery tufts in concentric rings of grayish-brown mass of conidia are developed. Towards maturity, infected fruits will generally develop into mummies, or they will develop a soft, dry rot.
The fungus was unknown in Europe until 2001, when it was observed for the first time in France.
A map can be downloaded from EPPO's website. See instructions here.
Monilinia fructicola overwinters in infected tissue in trees and in mummified fruit. Conidia may develop on all infected parts. Sexual spores are formed during spring on fallen mummified fruits. Conidia are formed and spread by wind throughout the summer. High humidity over a long period is necessary for infection. Free water on the surface of the plant parts for at least 15 hours or more are crucial for spore germination and infection. Optimum temperatures for infection range from 15-25° C.
Primary source of inoculum is introduced by imported, infected host plants or fruits.
Natural spread takes place by rain (water splash) or wind. Furthermore, insects may act as vectors.
Detection and inspection
Inspection in nurseries and orchards should be made in spring, before and during the flowering period. Fresh fruit imported from areas where M. fructicola occurs should be inspected carefully.
Pest status and importance
M. fructicola is one of the most destructive diseases of stone fruits, starting with blossom blight in spring, which causes reduction in fruit set, followed by fruit rots just prior to harvest. Fruit rots also occur under postharvest conditions, in storage and during transit. The disease caused by M. fructicola is not more serious than diseases caused by M. laxa and M. fructigena, both of which are widespread in Europe. However, Monilinia fructicola seems to be more variable than these two Monilinia species and consequently M. fructicola is likely to cause more serious losses in Europe.
Source of information
See further information here:
Author: Christiane Scheel
Editor: Dorthe Vestergaard