Foliar diseases can significantly reduce hay and milling oat yield and quality. The major foliar diseases of oats in Victoria include Red leather leaf, Bacterial blight, Septoria blotch, Crown (Leaf) rust and Stem rust. Recent surveillance activities in Victoria (2018-2021) identified Red leather leaf and Bacterial blight as the most common foliar diseases with other diseases such as Stem rust, Crown rust and Septoria blotch observed at low incidence.
Crops grown in the high and medium rainfall zones generally had higher disease severity compared to crops grown in low rainfall zones. In this chapter we describe the identification and management of these important foliar diseases affecting oats.
Overview of symptoms and the optimal temperature range for oat foliar diseases
| Disease | Pathogen | Symptoms | Optimal Temperature Range for Infection (°C) |
|---|---|---|---|
| Red leather leaf | Neospermospora avenae | Leathery textured reddish brown irregular shaped lesions on leaves | 5-16 |
| Stripe blight | Pseudomonas syringae pv. striafaciens | Reddish-brown stripes with yellow and red margins on leaves | Unknown |
| Halo blight | Pseudomonas syringae pv. coronafaciens | Yellow-brown oval shaped water-soaked spots with yellow-green halo on leaves | Unknown |
| Crown rust (leaf rust) | Puccinia coronata var. avenae | Small round to oblong, orange to yellow-coloured pustules on leaves, leaf sheaths and heads | 15-22 |
| Stem rust | Puccinia graminis var. avenae | Reddish-brown, powdery, oblong pustules with a characteristic torn margin on both sides of the leaves, on the stems and the glumes | 18-30 |
