Gummy stem blight: an emerging epiphytotic disease of pumpkin in Trinidad, West Indies

Authors

  • Judy Ramsoondar Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Cerano Da Silva Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Antonio Ramkissoon Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Chinnaraja Chinnadurai Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Adesh Ramsubhag Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies
  • Jayaraj Jayaraman Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies

Keywords:

Pumpkin, gummy stem blight, Didymella bryoniae

Abstract

Pumpkin 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.

Issue

Section

Research Papers