These spores cannot infect trees in the Rosaceae family.Powdery yellow, orange or chestnut-brown spores are released from infected leaves and fruit mid to late summer.Leaf spot and fruit infections grow slowly over the summer.If leaves and fruit are wet, spores are able to start new infections.
These spores can infect trees over a mile away.Spores produced on infected junipers and red cedar trees are carried by wind to susceptible apple, hawthorn or other plants in the Rosaceae family.Cankers of quince rust and witches' brooms of juniper broom rust go dormant but may survive for multiple years, releasing new spores each spring.After one season of spore release, galls of cedar-apple rust and hawthorn rust die and fall off the tree.Once weather becomes consistently warm and dry, spores are no longer produced on infected junipers or red cedar trees.Galls can rehydrate and dehydrate several times in one season in response to weather conditions.During dry spring weather, the orange, gummy structures shrivel and dry.In wet, spring weather, the galls produce orange, gummy, fungal growth that release spores.Cedar-apple rust and related rust fungi over-winter in infected branches and galls on juniper and red cedar trees.
0 kommentar(er)
