Phomopsis stem canker

The fungus Diaporthe eres is a serious plant pathogen that acts as the causal agent of various necrotic diseases, often referred to as Phomopsis stem canker. This ascomycete fungus is highly adaptable and can survive on dead plant tissues, infected seeds, and within the soil profile for several seasons.

It affects a broad range of hosts, including row crops like soybeans and sunflowers, as well as woody perennials such as grapevines, apple trees, and various berries. Its ability to infect diverse plant families makes it a significant threat to global agricultural productivity across different climatic zones.

Clinical symptoms typically appear as brown lesions on stems or branches. As the infection progresses, the lesions expand and eventually girdle the stem, restricting nutrient and water flow. This leads to wilting, premature leaf drop, and structural weakening of the plant. Small, dark, pimple-like pycnidia often erupt through the epidermis as the fungus produces spores.

Environmental conditions play a critical role in the development of Diaporthe eres. High humidity, frequent rainfall, and moderate temperatures are ideal for spore germination and colonization. The disease spread is most aggressive during periods of wet weather, which facilitate the transport of spores via wind and splashing rain to healthy tissue.

The economic impact is severe, as the pathogen causes widespread plant mortality, reduced seed yields, and inferior crop quality. Without active management, the disease can devastate entire fields, forcing producers to seek intensive chemical and cultural interventions to protect their harvest and minimize financial losses.

• Rotation with non-host crops to break the pathogen's life cycle.
• Use of high-quality, fungicide-treated certified seeds.
• Sanitation practices, including the removal and destruction of crop residues.
• Application of preventative and systemic fungicides during critical growth stages.
• Selection of resistant or tolerant cultivars suitable for the region.