Blueberries are a favorite plant amongst home gardeners because these bushes do not require a lot of space to grow, and the ripened berries are great eating which can be used to make jams and pastries. Along with the care and maintenance required, blueberry plants must be carefully watched to ensure that diseases that may reduce your harvest or kill your plant are prevented and stopped. By knowing what to look for, diagnose the problems on your own blueberry bush to keep your plant healthy.
Inspect the blueberries for a sunken appearance and see if the canes display dark brown marks. This condition points to anthracnose (ripe rot), which is preventable by regularly pruning out old/diseased stems and removing the berries after the fruit has been blue for at least three days.
Note the time of year that you see blueberry afflictions. For example, bacterial canker makes an appearance in January or early February by causing brownish red to black lesions on the stems and killing the fruit on one year old plants. Prevention includes cutting out diseased stems before rain fall, protecting your bush from freezes by using a cover like a blanket and sterilizing your pruning equipment with rubbing alcohol before using it on your plant.
Check the blueberry stems for leeching, flowering vines. Dodder is a plant that winds itself around the canes, turns the leaves of the bush red and reduces the amount of fruit grown. Weed out any invading plant life and apply an organic herbicide to fight this problem.
Look at the leaves of your blueberry plant to see if you find any browning on the veins, wilting and/or a light gray residue at the base of the foliage. Mummy berry is a fungal disease that shrivels up the fruit and makes it fall off of the bush. Management includes improving the drainage of the bush's soil, removing mummified fruit and planting only mummy berry-resistant varieties.
Search for any dying flowers and leaves on the bush. Scorch, or Sheep Pen Hill disease, is spread quickly via aphids and may kill the blueberry plant in severe cases. Burn any infected bushes, disinfect your harvesting tools and apply an organic insecticide to get rid of the insects.