The fungal disease called brownrotblossomblight strikes these succulent fruits in two stages: an early-season blight of blossoms and twigs, and a late-season soft rot of fruit. Especially destructive in warm, humid climates... Cause The fungi Monilinia fructicola and M. laxa can incite a blossomblight, a twig and branch dieback, and a fruit rot of several Prunus spp. including many ornamental and fruit trees. Fungi survive year to year on infected twigs, branches, old flower parts, or mummified fruit. Brownrotblossom/twig blight caused by Monilinia species is the most important blossom and pre-harvest (fruit) disease of prune in California. Generally, M. laxa is the primary pathogen on blossoms, whereas M. fructiola is the main pathogen on fruit. The brownrot fungus overwinters on mummified fruit that remain attached to twigs, infected blossoms that cling to twigs and on infected shoots. Fungal conidia are dispersed by wind and rain. The disease is more severe with wet weather. Another type of brownrotblossom and twig blight, called European brownrot, is caused by the Monilinia laxa fungus. This type seems only to attack sour cherry trees. If a tree in your yard is infected by the brownrot fungus, you will notice. Wilcox (25) studied brownrotblossomblight of sour cherry and demonstrated that incidence of blossomblight increased when inoculated plants were incubated at 8, 12, 16, and 20°C from 5 to10 h of wetness, and reached a level of 85 to 90% after 24 h of wetness. A risk assessment table of blossomblight was produced for different environmental conditions to guide the control of prune brownrot. Brownrot (Monilinia Fructicola and Monilinia laxa, AKA "blossomrot" and "blossomblight") is a devastating fungal disease that affects stonefruit: cherries, peaches, nectarines, apricots, and plums. It is also found on apples, though less commonly and less destructively. One application at full bloom is sufficient in most orchards in most years if there is low rainfall. If brown rot has been severe or in years of extended bloom accompanied by rainfall, a second or even third application near full bloom may be necessary. · Leaves on girdled shoots turn brown and remain attached. Infected fruit initially show a small brown spot which rapidly enlarges. The fruit remains fairly firm and often becomes covered with gray-brown fungus. Fruit may dry and harden into mummies, which serve as a source of infection in the spring. What are the Symptoms? Blossomblight: Brown rot is first seen as brown spots on the blossoms in the spring, causing them to turn brown, wither, and die. Infected wood: The infection can grow into the woody tissue, producing cankers that may kill the entire twig. Choose from a wide range of gardening supplies and accessories at Amazon. Read customer reviews & find best sellers. Free, easy returns on millions of items. Brownrotblossomblight symptoms include the collapse of spurs and leaves, and the base of infected flowers may secrete a gummy substance. Twig cankers have tan centers with dark margins. Brownrotblossomblight of pome and stone fruits: symptom, disease cycle, host resistance, and biological. control. Holb, I. J. University of Debrecen, Centre of Agricultural Sciences, P. O Box 36. H- 4015 Debrecen, Hungary.
