| Disease | Organisms | Symptoms | Occurrence | Hosts | Control |
|---|---|---|---|---|---|
| Ascochyta blight | Didymella pinodes (synonym: Mycosphaerella pinodes) Phoma medicaginis var. pinodella Phoma koolunga Didymella pisi | Most obvious on stems and leaves. Purplish-black discolouration of lower stem. Dark brown spotting of pods and leaves. Blackening of tap root | Common in all pea growing regions; most crops are affected to some extent. Favoured by wet conditions. Most damage in early sown crops | Peas and most legumes | Crop rotation Later sowing Seed dressings Disease free seed |
| Bacterial blight | Pseudomonas syringae pv. pisi P.syringae pv. syrinage | Water-soaked spots on leaflets and stipules. Yellowish brown fan-shaped lesion on stipules | Sporadic in wetter regions. Most severe in early sown crops already damaged by frost or heavy rain | Peas for pv. pisi and alternate hosts for pv. syringae | Crop rotation Disease free seed Resistant varieties |
| Downy mildew | Peronospora viciae | Brown blotches on upper leaf surface. Underside of leaves covered by masses of fluffy ‘mouse-grey’ spores | Sporadic in all regions. Damage most severe in wetter districts | Peas | Resistant varieties Seed fungicide treatment |
| Powdery mildew | Erysiphe pisi | Leaves covered by a film of powdery white spores. Infected plants have a blue-white colour | Can occur in most regions towards the end of the season. Most common in late-sown crops | Peas | Resistant varieties Avoid late sowing Apply Foliar fungicide at flowering as an economic option for disease prone areas |
| Septoria leaf blotch | Septoria pisi | Straw coloured blotches on leaves, stems and tendrils. Pin-head size black spots within lesions | Present in most pea growing regions. Damage most severe on short, semi-leafless varieties | Peas | Destroy crop residue. Most varieties are moderately susceptible. Crop rotation |
| Pea seed borne mosaic virus | Virus | Downward curling of leaves, mosaic, stunting | Present in all pea growing regions | The host range is limited to Fabaceae | This virus is highly seed-borne in peas. Virus-free seed is recommended. |
| Turnip yellows virus (formerly Beet western yellows virus) | Virus | Yellowing and stunting | Prevalent in all pea production areas | Very wide host range. Most pulses and brassicas and many weed species | Managing aphids and weeds, resistant varieties. |
