The Monilia or Monilinia, also known as moniliosis, brown rot or mummified it is a disease that generates significant losses in stone fruit trees.
Monilia spp especially affects stone fruit (cherry, nectarine, apricot, peach, plum, almond…). Although it can also affect pip fruits such as apple tree or pear.
Currently four species of Monilinia spp: M are described. lax, M. fructigena, M. fructicola and M. polystroma.
In Europe we mainly find Monilinia Laxa which affects mostly stone fruit and Monilia fructigena which affects more well to the pip fruits.
Monilinia fructicola is not detected in Spain until 2009. The particularity of this mushroom is that it produces apothecia (“lichens“) that act as a primary inoculum. It is feared that its expansion will be rapid and will eventually displace the other strains.
Cycle and development of Monilinia Spp
The ideal conditions for the development of the Monilinia occur during spring.
Contact with rain, high relative humidity and mild temperatures (23-25 ° C) encourage the development of the illness. If the conditions are favorable, some fruits will be affected despite the performance of treatments. However, if treatments are not performed it is possible to lose the harvest altogether.
Although these conditions are optimal, the fungus can develop in a temperature range between 5 and 30 ºC.
The moniliosis inoculum spends the winter in the branches, buds and mummified fruits in the spring. These infection sites release spores or conidia at the beginning of spring.
They infect the flowers through stigma. The fruits are affected especially during the maturation phase.
The fruit with wounds (fly bite , raindrops, hail, drosophila suzukii ) is especially sensitive to infection, although later the fungus can be extended by contact.
Due to its good capacity for expansion through contact between fruits, the most productive varieties of fruit trees tend to suffer the greatest incidence of the disease.
During the commercialization phase if the fruit is exposed to high humidity conditions (condensation due to temperature change, high relative humidity…) the cherry brown rot can attack with virulence and cause significant losses.
Damage caused by brown rot of stone fruit
The damages caused by the fungus Monilia Spp are very considerable. These damages can begin with the flowering and extend to the fruits both in field and in camera.
Producers and distributors of fruit should strive to apply treatments and look for new control techniques.
During the rainy springs it is common for the fungus to infect cherry blossoms or other crops. The flowers dry, necrotic and clump together, remaining firmly united with each other.
-The mummified flower produces a decrease in the fruit set and reduces potential crop. This usually happens when it rains several times during flowering. The level of incidence may be reduced with the application of fungicides before flowering.
If the climatic conditions allow it, the Monilinia spp, continues extending reaching the zone of beginning of the outbreak (buds). This produces a chancre on the tip of the floral bud that if it becomes generalized to Rest of buds completely dry out the bud.
– Weakening of fruit trees and loss of productive shoots.
Studies conducted in Spain during 2010 indicate that Monilinia Laxa accounted for more than 80% of infections in stone fruit.
The damages produced in the fruit are those of greater repercussion.
– Production reduction.
– Increase in collection costs (greater selection difficulty).
– Commercial depreciation of the fruit (the holding time in the chamber is reduced).
Cultural control and applications of treatments against Monilinia
They should be aimed at reducing the presence of Monilinia foci (inocula) on the crop.
During pruning they should remove the branches affected and the mummified fruits. The remains of pruning and fruits with the presence of Monilia should be eliminated (burning is a good option).
They favor infection: excessive pruning, nitrogen fertilizers and excessive irrigation.
Reduce the likelihood of infection: green pruning, cup thinning.
Nurseries should ensure that the buds used for the grafts are free of the fungus.
Chemical treatments for the control of Monilinia Spp
The application of two annual cupric treatments (admitted in organic farming) is recommended.
One we will do it in autumn at leaf fall and another before fruit trees come out of winter rest. This considerably reduces the inoculum load of Monilinia Spp existing in the plantation, helping to control other fungi such as anthracnose or the screening .
The treatments with fungicides are authorized after the petal fall, before they can negatively affect the beneficial populations of bees and pollinating insects.
In cherry, this treatment is usually done together with insecticides for the aphid control .
You should have a systemic fungicide treatment after the fall of the petal and additional weekly treatments when rains occur or prevent.
In the case of cherry, when cracks occur, infection is very likely despite the affected control treatments.
WARNING: To avoid creating resistance, toggle is treated with different authorized active materials.
In winter, the application of urea treatments is recommended to help break down organic matter and favor the fall of infected leaves to the ground.
Resistance of cherry varieties to Moniliosis
Each cherry variety has a different response to infection with Monilia spp. Although they are not completely difficult if there are important differences between varieties.
A significant part of the information, comes from Spanish research organizations. When phytosanitary products are used, it is important to verify that their use is currently authorized in the country of application.