DISEASE COMPOSITION AND DEVELOPMENT OF POWDERY MILDEW (Erysiphe cichoracearum) AND DOWNY MILDEW (Pseudoperonospora cubensis) ON CANTALOUPE CULTIVATED IN GREENHOUSES IN SOME SOUTHERN PROVINCES OF VIETNAM

Abstract

A survey was conducted in 2022 to identify the disease composition and monitor the progression of powdery mildew (Erysiphe cichoracearum) and downy mildew (Pseudoperonospora cubensis) on cantaloupe cultivated in greenhouses in Ho Chi Minh city, Tay Ninh and Binh Thuan province. The results indicated that in Tay Ninh province, eight diseases were identified on cantaloupe, whereas seven diseases were recorded in Ho Chi Minh city and Binh Thuan province. Among these, one bacterial pathogen causing leaf blight and eight fungal pathogens were identified. Powdery mildew and downy mildew were the most prevalent diseases across all surveyed regions. Powdery mildew appeared during the fruit-setting stage, approximately 30 days after transplanting and caused relatively severe damage in Ho Chi Minh city and Binh Thuan province. The incidence and disease index of powdery mildew in Ho Chi Minh city reached 43% and 18.65%, respectively. Downy mildew emerged earlier, around 20 days after transplanting, developed rapidly and caused significant damage at the late growth stage in Tay Ninh province and Ho Chi Minh city. The incidence of downy mildew was 54% in Ho Chi Minh city and 51% in Tay Ninh province, with corresponding disease indices of 23% and 18.78%, respectively.