Anthracnose Blight

Important Gardening Information about Anthracnose Blight


People who garden or who have landscaped yards with flowering plants and trees all know the benefits of weeding, fertilizing and pruning, but many are unaware of another problem that can afflict their lovely gardens; anthracnose blight.  When it strikes, it can affect numerous plants if not caught and halted in the early stages of the disease, causing loss of plants and produce.


What is it?


Anthracnose is a term that refers to a group of fungus, and blight is a term for disease that can cause wilting and dying of an otherwise healthy plant.  The two together signify a fungus disease which affects in particular vegetable plants and shade trees.  Anthracnose can be composed of several types of fungus, each of which produce spore like structures called acervuli.  The acervuli will break through the tissues of the plant and can appear as small black dots on twigs and branches.  On tree leaves, the spotting may be difficult to spot in the beginning stages, occurring often along the major veins of the leaf.  These spots increase in size and change coloration from tan to darker reddish black to black, signifying the death of the leaf.  Vegetable plants will generally experience a small darkish circle on lower leaves, which grow in size and cause yellowing of the entire leaf over time.  The disease begins at the lower portion of vegetable plants and works its way upward, destroying plant tissue as it goes.


Causes for anthracnose blight


Different experts have different ideas on the exact cause of this disease, but the majority seems to agree that humidity plays a very large role in the development of the fungus.  High levels of rainfall or watering combined with the heat of the summer days can create a steamy, warm environment that is conducive to the growth of fungus.  Soil conditions may also lend a hand in providing ideal conditions for the disease.


How to prevent the disease


When trees and perennial plants are the target of the blight, simple prevention tactics are possible to minimize the possibility of the growth of the fungus.  The spores of the fungi can “hibernate” through the winter months under the myriad of fallen leaves, twigs and branches underneath the plants.  As the warmth of spring emerges, so do the spores; arising to infect new growth on the plants.  Eliminating this incubator of the fungus by raking and burning the fallen leaves before the disease has the opportunity to develop will provide a huge reduction in the possibility of disease.


For vegetable gardeners, carefully examining and monitoring the status of the plants is vital to discovering the development of anthracnose blight in its early stages.  Removing the leaves that have been damaged is the first step in keeping the disease from spreading to other plants in the garden.  Particularly susceptible plants are tomatoes and watermelon.  After completely eradicating these leaves from one plant, wash your hands before proceeding to the next plant to avoid spreading the disease by hand.  If the disease has spread upwards onto the plant, it may be wiser to simply pull out the plant and destroy it away from the gardening area.  It is important to note that the fungus spores can continue to live in the soil for up to 2 or 3 years, so planting tomatoes or watermelon in a different section of the garden in future years is advised.


Keeping air circulation throughout the garden is helpful in allowing leaves to dry out between watering and rain, further helping to prevent the disease.


Gardeners often know the tricks of the trade for preventing weeds and bugs from invading their prized plants, but many are unaware of the ease in which anthracnose blight can infect and destroy these plants.  Taking a few steps to monitor and protect their plants will result in the beautiful and productive plants, the goal of every gardener.