Pepper spot and scorch

Leptosphaerulina arachidicola

Minor but widespread. Leaves drop off. Is often one of the earliest foliar diseases to infect crops.

The same fungus causes two different symptoms under different weather conditions. Pepper spot occurs when very small spots, under 1 mm, develop on the top of the leaf. Scorch occurs when a V-shaped part of the leaf dies (usually on the margin) and a yellow zone forms next to it.

The fungus survives on peanut residues and is spread by wind.

Chemical
The fungicides used for controlling the other foliage diseases usually control this organism. Use a protectant fungicide if no other disease influences the choice.

Cultural
These diseases are not normally serious in traditional production areas using the current varieties.

Chemical registrations and permits
Check the Australian Pesticides and Veterinary Medicines Authority chemical database and permit database for chemicals registered or approved under permit to treat this disease on the target crop in your state or location. Always read the label and observe withholding periods.