Cone tip blight

Cone tip blight is a fungal disease that primarily affects the hop plant (Humulus lupulus). It is caused by various pathogenic fungi, most commonly species of Fusarium, which target the developing cones of the plant. This disease is classified as a fungal pathogen infection that disrupts the maturation of the hop cones.

The primary crop impacted by this pathogen is the common hop, grown extensively for the brewing industry. The infection is particularly devastating because it attacks the reproductive structures of the plant, which are the most valuable parts of the hop crop, directly impacting the yield and the essential oil content required for beer production.

Symptoms of Cone tip blight typically begin with the browning and necrosis of the tips of the bracts (petals) on the hop cone. As the infection progresses, the browning spreads throughout the entire cone, leading to a dried, shriveled appearance. Under high humidity, a fungal mycelium might become visible on the surface of the affected bracts.

The development and spread of this disease are driven by environmental conditions, particularly high humidity, frequent rainfall, and warm temperatures during the late stages of cone development. The pathogen often overwinters in plant debris in the soil, and secondary infections can occur via wind dispersal of spores or through mechanical wounds caused by insect pests.

Control measures are essential for maintaining hop health and include:

• Implementing strict sanitation protocols to remove and destroy infected plant residue.
• Managing insect populations to prevent mechanical injury to the cones.
• Applying registered fungicides at the appropriate growth stages to inhibit fungal growth.
• Promoting good air circulation within the hop yard to reduce canopy humidity.