Neofusicoccum protearum

Neofusicoccum protearum is a significant fungal pathogen within the Botryosphaeriaceae family, known for causing necrotic lesions and cankers on various plant species. It is particularly noted for its impact on Protea crops, posing a threat to both commercial production and ornamental nurseries worldwide.

The pathogen primarily affects the stems and branches of host plants. By colonizing the woody tissues, it obstructs the vascular system, which leads to the collapse of the plant's structural integrity. While Protea is the most frequent host, the fungus can impact other woody shrubs under suitable environmental conditions.

The most distinctive symptoms are the development of sunken stem cankers, which often start as minor discoloration and progress into deep lesions. As the infection deepens, the foliage above the canker begins to wilt, chlorose, and eventually dies. In humid conditions, small black pycnidia may appear on the surface of the infected areas.

Environmental conditions play a critical role in the epidemiology of this disease. Spores of Neofusicoccum protearum are dispersed by water splashes and wind, making rainy periods highly conducive to infection. The fungus often exploits wounds caused by pruning, insects, or environmental stress to enter the plant tissues.

Management of this disease requires an integrated approach focusing on prevention. Removing infected plant debris reduces the inoculum source significantly. Applying protective fungicides after pruning and during high-risk rainy periods is essential to prevent new infections. Maintaining plant health through proper nutrition and irrigation also helps in mitigating the susceptibility to the pathogen.

• Sanitary pruning of diseased stems and disposal by burning.
• Sterilization of pruning tools to prevent cross-contamination.
• Application of systemic fungicides during the growing season.
• Minimizing plant stress through appropriate soil management.