Treating Fungus on Plants in the Tropics

Treating fungus on Mango Trees and other plants

Because of the humidity in our area, some plants are prone to fungal diseases. Here is a tip that helps control fungus on Mango trees. Fungus is spread from spores that live in dead leaves on the ground. Once the tree is infected, the spores are transmitted to other branches via water droplets. During lengthy, rainy springs the disease is readily transmitted throughout entire area and can transfer to other plants and flowers.

 Types of fungus–Powdery Mildew, Anthranose and Mango Scab

1. Powdery mildew appears as a white powder on the leaves, flowers and fruit. Dark brown spots with a greasy appearance form along the bottom side of the leaves as the season progresses.
2. Anthracnose is a fungus that attacks the leaves, branches, fruit and flowers on the mango trees. Symptoms of an infection are sunken black spots that are irregular in shape. The spots enlarge as the infection goes untreated, and cause blossom blight and fruit rot.
3. Mango scab is a less common fungus infection on mango trees. This type of fungus infects the leaves, branches, flowers and fruit on a mango tree. This infection looks similar to the Anthracnose fungus in the early stages, but then will form a brown tissue on the fruit and cause the leaves to become distorted.

Treatment

The treatment is two-pronged.

• First, it is important to remove dead leaves and branches at the end of every growing season.
• Second, the trees may be treated with a fungicide at several intervals, which include starting at the beginning of the growing period and ending post-harvest.

Available Fungicides

It is recommended by fruit growers that you spray with a fungicide that contains copper as the active ingredients directly on the leaves and branches of the trees. Choose an overcast day when no risk of rain exists to prevent burning the delicate flowers or fruit on the trees. Application should be from the time when buds bloom until the end of harvest helps prevent an outbreak of the fungus.

Monitor the new growth on the tree and apply fungicide to these areas when reapplying the treatment. More frequent applications of the fungicide may be needed in a rainy season since rain can decrease the effectiveness of the treatment.

Home Depot in Playa Del Carmen has a fungicide called brand name Nutriplant with cobre(sl) 250 ml. that our members have used to success.  Read carefully the directions and warnings on the label of the fungicide you purchase. Some are applied weekly, some at bloom and then at harvest.

Our thanks to Dan Freeman and the Mayan Garden Club for this contribution. The pictures are after treatments and the plants are healing.