Pelargonium necrotic spot virus

The causative agent is the Pelargonium necrotic spot virus (PNSV), a member of the Tombusvirus genus. It is a systemic viral pathogen that infects plants at the cellular level, disrupting normal physiological processes and resulting in severe morphological changes and reduced plant vigor.

The virus primarily affects various species and hybrids of the genus Pelargonium. While primarily a concern for greenhouse production, it can have significant economic impacts on nurseries where the cultivation of geraniums is the main commercial activity, leading to heavy losses of saleable stock.

Symptoms typically manifest as chlorotic spots on leaves, which subsequently turn into necrotic lesions. Growers may also observe ring spots, mosaic-like patterns, yellowing of the veins, and generalized stunted growth. In severe infections, internodes become shortened, and the foliage loses its natural color and shape.

The transmission of this virus occurs mainly through infected propagation material, such as cuttings. Because the virus is mechanically transmissible, it spreads easily via contaminated cutting tools, hands, or through direct contact between infected and healthy plants during routine cultivation practices.

Management relies on strict sanitation and disease exclusion protocols:

• Strict selection of virus-free parent plants for propagation purposes.
• Sanitizing pruning shears and other tools with appropriate disinfectants after every contact.
• Immediate removal and destruction of symptomatic plants to prevent further spread.
• Implementing rigorous hygiene standards in greenhouse environments to minimize mechanical transmission risks.