Onion farmers in Nueva Ecija are facing a serious threat from anthracnose-twister disease, known locally as ‘kulot.’ This disease causes symptoms like leaf spotting, twisting, and neck elongation, and can destroy up to 80% of their harvest, leading to significant production losses.
To help address the anthracnose-twister disease, a research team from the National Crop Protection Center-College of Agriculture and Food Science, University of the Philippines Los Baños (NCPC-CAFS, UPLB), is developing sustainable control strategies under the project, “Chemical and Biological Management of Fungal Species Complex Inciting Onion Anthracnose-Twister” led by Scientist Melissa P. Montecalvo.
The project, supported by the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD), aims to provide sustainable chemical and biological management recommendations that can potentially reduce the incidence of onion anthracnose-twister that can help boost onion yields and income of growers.
In a project review, Ms. Montecalvo reported that the team has already collected a significant number of Colletotrichum and Fusarium isolates from symptomatic onion varieties in various onion fields in Nueva Ecija. These isolates are being tested against various fungicides to find the most effective treatment. The team also investigates the characteristics of aggressive strains of the fungi and their potential resistance to current treatments.
Furthermore, the team is also testing the effectiveness of potential biological control agents as an eco-friendly way to manage the disease. They aim to understand how these biological control agents work, examining both their actions against the pathogens and their role in enhancing plant resistance to future infections.
During their recent visits to Nueva Ecija, Ms. Montecalvo’s team found that most growers primarily cultivate red onion varieties and heavily rely on fungicides to control the spread of the disease.
In addition, they found that only a few farmers use Trichoderma as a biological and sustainable control alternative against the disease. The team has also identified potential alternative host plants of onion anthracnose-twister disease, such as: barnyard grass, spreading dayflower, and four sedges.
To further understand the disease's spread, they will conduct cross-infection experiments as part of the project’s future activities to study if the pathogens isolated from these alternative hosts can infect onion plants.
Moreover, Ms. Montecalvo reported that fall armyworm (Spodoptera frugiperda), is a major pest concern, along with persistent weed problems.
By understanding the pathogens, identifying the most effective fungicide, and knowing how the disease spreads, the project team will be able to provide farmers a holistic and effective management strategy for onion anthracnose-twister.
Present in the activity were representatives from UPLB, Southern Tagalog Agriculture, Aquatic, and Resources Research Development and Extension Consortium (STAARRDEC), and DOST-PCAARRD, led by CRD Program Monitoring and Evaluation (PME) Section Head Kristine Joy P. de Guzman and Industry Strategic S&T Program (ISP) Manager for Vegetables Joel Norman R. Panganiban along with S&T Consultant and De La Salle University Professor Dr. Mark Angelo O. Balendres, who served as the technical evaluator of the project.