Haman-gun Urges Early Control Amid Concerns Over Spread of 'Onion Downy Mildew'

Early Pest Control in Cultivation Farms

Concerns Over Frequent Rain and High Temperatures Causing Diseases and Pests

Haman-gun, Gyeongnam Province, requested onion growers in the county to thoroughly control downy mildew from last winter to early spring this year due to concerns about pest and disease outbreaks caused by frequent rainfall and continuous high temperatures.

When frequent rainfall reduces sunlight, crops tend to grow excessively tall, making leaves and stems weak and vulnerable to pests and diseases.

Haman County urged thorough early control measures amid concerns over the spread of 'onion downy mildew.'
[Image provided by Haman County]

In particular, downy mildew occurs when pathogens invade onion leaves under high temperature and humidity. Due to recent continuous rainfall and cloudy weather, insufficient sunlight and a hot, humid growing environment have been created, raising concerns about the spread of downy mildew after March.

Downy mildew is a fungal disease that initially causes leaves to turn pale yellow, then symptoms spread in circular patterns with gray thread-like mycelia and fungal clusters appearing on the leaf surface.

Typical symptoms of downy mildew include leaf tissue hardening, leaves becoming limp and abnormally growing, leaves drying and dying leaving only leaf sheaths, white spots on leaves, and dense gray or black spore masses on the leaf surface.

Downy mildew can worsen after rain, so preventive control before rainfall is necessary. Applying control measures three times at seven-day intervals during the early stages of infection can effectively prevent its spread. Onion fields should be carefully monitored to check the disease spread status and appropriate pesticides should be applied. Approved pesticides can be checked on the Rural Development Administration’s Pesticide Safety Information System.

Additionally, when applying topdressing fertilizer to overgrown onions or garlic, nitrogen fertilizers promote crop growth but can worsen damage symptoms in weakly grown crops, so it is better to apply less than the recommended amount.

A county official said, “We ask for your utmost efforts in final pest and disease control and crop growth management to ensure stable production of onions carefully cultivated by each farm during winter and to increase farm income.”

This content was produced with the assistance of AI translation services.