ANTHRACNOSE OF THE ANNONACEAE IN PUERTO RICO

Abstract

The incidence of Gloeosporium gloeosporioides anthracnose on the Annonaceae in Puerto Rico seems to be correlated with high relative humidities. Experiments have shown that the Annonaceae are seriously attacked by the anthracnose fungus in the northeastern and wet inland regions of Puerto Rico. The disease is responsible for a constant drop of flowers and fruits, a die-back of twigs and branches and a damping-off of the seedlings. The growing of Annonaceae is commercially impossible under unfavorable environmental conditions, such as high atmospheric moisture. Annonaceae are found growing almost free from anthracnose in the dry south and southwestern part of Puerto Rico, developing well and producing heavy crops. The casual agent of infection is a polymorphic organism, involving many forms, exhibiting different morphological characters, such as color of colony, color of spore masses, and type of mycelium.