Alternaria Leaf Spot - Hosta
Friday, 17 June 2005 13:13
Alternaria diseases are common on many ornamental crops. This week it showed up on field grown hostas.
Alternaria spp. is a fungus disease that causes small leaf spots with reddish-brown margins. Leaf spot symptoms may vary depending on species and host plant. Alternaria sporulates under moist conditions and spreads by splashing water or air. To manage leaf spot diseases, avoid overhead watering late in the day and on overcast days and remove heavily infested foliage. Eliminating water on leaves is important to control Alternaria leaf spot. Fungicides that can be used to protect foliage and have been shown to be effective include: Chlorothalonil (Daconil Ultrex), azoxystrobin (Heritage 50 WG), fludioxonil (Medallion 50WP), mancozeb (Protect).
Photos: Alternaria leaf spot on Hosta, 2
Tina Smith
