Brown Rot Control
BROWN ROT CONTROLBrown rot is caused by a fungus that produces spores, and can be a major problem during particularly wet seasons. Prolonged wet weather during bloom may result in extensive blossom infection. The length of wet periods required for blossom infection depends upon the temperature. Under optimum conditions for the fungus, entire fruit may be rotted within 48 hours of infection. As fruits mature, decay spreads from the lesion throughout the entire fruit. Extended exposure can lead to severe crop loss.
|HOST PLANTS: Common in stone fruits such as cherries and plums but also observed in apricots, almonds and peaches.
SYMPTOMS: Infected blossoms wilt, shrivel and become covered with greyish mould. Petals may appear light brown or water-soaked. Blighted blossoms do not produce fruit. Dead blossoms may stick to spurs and twigs until harvest, providing a source of spores for the fruit rot phase. On peaches and apricots the infection may spread to twigs, causing brownish, oval cankers that may girdle and kill twigs.Fruit rot appears as small, circular brown spots that increase rapidly in size causing the entire fruit to rot. Greyish spores appear in tufts on rotted areas. Infected fruit eventually turn into shrivelled, black mummies that may drop or remain attached to the tree through the winter. Brown rot can be serious on injured fruit such as cherries split by rain.
FAVORED ENVIRONMENT: Humid wet conditions are when the fruit trees are most at risk from infection. Young green fruit can be infected just before autumn, but the infection often remains inactive until near maturity of the fruit. Brown rot can spread after harvest. Mature fruit can decay in only 2 days under warm conditions. The fungus over-winters in mummified fruit on the ground or in the tree and in twig cankers.
BROWN ROT CONTROL: Prune flowering trees during blooming when wounds heal fastest. Remove wilted or dead limbs well below infected areas. Avoid pruning in early spring and fall when bacteria are most active. Make sure to disinfect your pruning equipment (one part bleach to 4 parts water) after each cut. If using string trimmers around the base of trees avoid damaging bark to prevent infection. Brush bark with white latex paint diluted with water to reduce bark-damaging temperature fluctuations. Trees may be protected with copper fungicides applied to the trunks and lower branches. Remove weeds and grass from around the base of young trees to improve air circulation and keep the trunk and crown dry. Spraying young trees with a copper fungicide prior to planting will help provide control.
Products for Brown Rot Control