Cankers On Blossoms

Bacterial Infections

• Caused by several bacteria and affecting all manner of plants, bacterial infections are often spread in much the same way as fungi. Fire blight, among the more common canker causing bacteria, is spread via wind, rain or insects from infected bark to blossoms and leaves. Sometimes called "blossom blight" fire blight's first symptoms are usually water soaked, wilted blossoms that eventually turn black and droopy. Bacterial cankers can infect fruit trees and there is even a blossom blight that affects tomatoes.

Control

• Sanitation is one of the most effective control methods for bacterial pathogens. Pruning cankers on trees, shrubs and perennial plants can reduce the amount of overwintering bacteria. Fewer bacteria means re-infection will not be as severe or will not be present at all in the spring. Remove all diseased material from planting beds and destroy or dispose of it. Copper bactericides can be helpful for some plants, read the manufacturer's label carefully for any product you buy. Many annual fruit and vegetable varieties are resistant to bacterial infection, plant these whenever possible.

Fungal Infections

• As with bacteria there are several fungi that can cause disease symptoms on blossoms. Fungi overwinter in living or dead tissue and are spread by wind, water, insects or animals. Wet, cool spring or fall weather is often the catalyst for spore production and are usually when symptoms begging to appear. Brown rot is a common fungal infection of fruit trees that causes cankers, brown, wilted blossoms and rotten fruit.

Control

• Pruning out infected branches on trees, shrubs and perennial plants can help reduce the spread of infection. Pruning can also thin out canopies, improve airflow and increase light penetration to help eliminate fungal spores. Clean up any fallen, infected debris and destroy or remove it. Copper fungicides are often effective but always read and follow the manufacturer's directions carefully before applying chemicals to your plants.