Gummy stem blight: an emerging epiphytotic disease of pumpkin in Trinidad, West Indies
Keywords:Pumpkin, gummy stem blight, Didymella bryoniae
AbstractPumpkin fields in Trinidad have been noted to become increasingly afflicted by gummy stem blight. This disease is caused by Didymella bryoniae which is known to target most cucurbit crops. Symptoms can occur on either the leaf, stem and or fruit of the plants, as drying of plants leading to premature death and significantly decreased yields of the crop. Field data on disease incidences were collected in Trinidad, along with sample isolations and confirmation of the pathogens through morphological characterization. It was observed that gummy stem blight had a greater incidence during the wet as opposed to the dry season and also in comparison to all other pumpkin foliar diseases observed. Of the isolations done, a total of 12 pathogen isolates were obtained which were all identified as Didymella bryoniae according to spore morphology and cultural characteristics. Pathogenicity tests were carried out on crops belonging to the cucurbit family utilizing representative cultured isolates. All the cucurbitaceous hosts screened, developed characteristic symptoms of the disease and were found to be susceptible.