Phyllosticta Leaf Spot

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Phyllosticta Leaf Spot

Phyllosticta arachidis-hypogaea

Fungus


In a Nutshell

  • Circular to irregular light tan lesions surrounded by marked reddish-brown margins appear on leaves.
  • As the disease progresses, the lesion becomes grayish and dry up, eventually falling off, leaving a hole, giving the leaves a ragged appearance.

Hosts

Peanut

Soybean

Symptoms

Circular to irregular light tan lesions (1.5 to 5 mm) surrounded by marked reddish-brown margins appear on leaves. As the disease progresses, the center of the lesion becomes grayish and dry up, in some cases eventually falling off, leaving a hole and giving the leaves a ragged appearance. The lesions may coalesce to form large, irregular, necrotic patches. Black, pepper-like fungal specks are visible within the diseased tissue on both leaf surfaces.

Trigger

The fungus can remain viable for about one year in infected crop debris in the soil. From the soil, it usually infects damaged and necrotic tissues of plants that are affected by other diseases or injured during field work (secondary infection). It then spreads to healthy tissues and triggers specific symptoms. Optimum conditions for fungus development and disease progression are temperatures between 25-30°C and pH values between 5.5-6.5. Phyllosticta Leaf Spot is not considered a major disease of peanut.

Biological Control

Sorry, we don't know of any alternative treatment against Phyllosticta arachidis-hypogaea . Please get in touch with us in case you know of something that might help to fight this disease. Looking forward hearing from you.

Chemical Control

Always consider an integrated approach with preventive measures together with biological treatments if available. Damage from Phyllosticta leaf spot is usually minimal, therefore fungicides are rarely recommended.

Preventive Measures

Use resistant varieties if available.,Be careful not to injure plants during field work.,Remove crop debris after harvest and burn it.,Spread lime in fields to increase soil pH values.