Brown rot of pome trees is caused by Monilinia fructigena, which most often affects apple and pear trees, while stone trees, i.e. plums, peaches, cherries and cherries, suffer from the fungus Monilinia laxa. Brown rot also occurs on hazel and is caused by Monilinia coryli.
Symptoms and causes of the development of the disease
" The first symptom is brown rot on the surface of the fruit. After some time, pinhead-sized cream pillows appear at the discoloration site, usually arranged concentrically.On them, spores are formed that infect other fruit, which, while rotting, fall or dry, remain on the tree as the so-called mummies. In spring, the cream pillows are re-formed on the mummies, spores are released from them and the cycle repeats. "
" In the case of stone trees, as a result of infection with brown rot, there is also gangrene of flowers and branches. Infected flowers rapidly die and turn brown. Under favorable humidity conditions, the disease may lead to the death of all flowers and young twigs within a few days. From flowers, the infection spreads to shoots, sometimes occupying older branches with dried leaves. The fungus hibernates in mummies and cream pillows on infected branches. "
Disease is favored by high humidity and temperature around 20-25 ° C. Fruits are contaminated where the skin breaks due to insect damage, hail or other mechanical factors.
Prevention
The fight against brown rot involves collecting and destroying mummies remaining on infected trees during the winter. You also need to clear the soil from fallen rotten fruits. They should not be thrown onto the compost, as the spores that are released will be transferred to he althy plants with the wind. Infected shoots should be cut out, and the places of cut should be covered with garden ointment.
In the case of apple and pear trees, it is recommended to perform chemical treatments after fruit bud fall in June, using, for example, Pomarsol Forte 80 WG, Sadoplon 75 WP or Kaptan 50 WP. In contrast, for spraying stone trees, the best time to combat brown rot is before and after flowering. You can use: Baycor 25 WP, Miedzian 50 WP, Punch Bis 400 EC or Topsin M 500 SC. If necessary, treatments on plums are also performed after flowering and at the turn of July and August. As for hazel, spraying is carried out, starting from the second half of May, with the following preparations: Dithane M-45 80 WP, Pomarsol Forte 80 WG or Sadoplon 75 WP.
