When was the last time you spotted a thriving citrus grove in Bermuda? The sight has become a rare one thanks to a fungus (commonly called the Postbloom fruit drop) that is attacking a variety of local citrus tress.

The Postbloom fruit drop of citrus is often the reason why small fruit drop off local trees.

Local estimates for 1995 put the losses as high as 36.6 percent in grapefruits and 36 percent in oranges.

Agriculture, Fisheries and Parks' Carolyn Douglas said the Postbloom fruit drop was first noticed in 1956 in Belize and since then has continued to spread to all areas where citrus trees grow.

"Postbloom fruit drop is a disease that results from the infection of blossoms by a virulent strain of fungus called Colletotrichum gloeosporiodes,'' she said.

The fungus thrives in wet, humid weather conditions and Ms Douglas said Bermuda experienced suitable growth conditions for the fungus between the months of February and April.

The fungus survives between blooms on the surface of leaves and twigs until spring when more spores are produced in the presence of moisture.

Ms Douglas said the fungus was spread by a variety of means including rain, insects and human contact. According to the Department of Agriculture data, spores are produced in abundance on infected plants.

The spores, which germinate within 24 hours, are dispersed by travelling insects, rain and even human contact.

New petals will become infected within 24 hours and will produce new spores in about four days.

Ms Douglas urged citrus growers to keep an eye out for symptoms that the fungus may be attacking their trees.

"The first symptoms of the disease is red-brown streaks on the petals, usually not obvious until the open-flower stage,'' Ms Douglas explained. "The open petals look salmon in colour with water soaked patches. "The flowers are the beginning stages of the fruit. If all the flowers are lost by this fungal problem there will be no fruit.'' And she said that the patch carrying the fungal spores can spread to the entire tree.

"The blighted petals remain firmly attached on the branches and the entire flower cluster may be attacked,'' Ms Douglas added. "After the flowering stage the tiny fruits separate from the base of the ovary leaving a button look where the fruit should be attached.'' Fungus and citrus fruit drop, she added.

To protect your tree from the disease, Ms Douglas recommended spraying blossoms with a fungicide called Benlate.

"The application of protective sprays only need to occur when periods of prolonged wetness are expected to coincide with peak blossoms,'' she said.

"Timing of sprays of a fungicide is of utmost importance in controlling this fungal disease.'' The Department of Agriculture has a supply of Benlate which is available to the public at no charge.

The spray can be collected from the Laboratory anytime between 8.30 a.m. and 4 p.m. Mondays through Fridays.

For more information contact the Agricultural Department at 236-4201.