Oak twig blight
Cryptocline cinerescens
What is Oak twig blight (Cryptocline cinerescens)?
Oak twig blight, caused by Cryptocline cinerescens, is a fungal disease affecting coast live oak, interior live oak, and valley oak. It sporadically causes twig blight, with infected shoots turning white or tan and dying. The disease is prevalent in areas with frequent rains during new leaf production. Symptoms include straw-brown leaves on blighted shoots, remaining attached for several months. The disease does not kill large branches or entire crown sections. Infected trees may show a general thinning of the crown.
How does Oak twig blight (Cryptocline cinerescens) occur?
Cryptocline cinerescens, the fungus responsible for oak twig blight, reproduces through spore production and dispersal. The spores are typically released during rainy periods when new leaves are being produced. The fungus infects the current season's growth, causing the shoots to die. Infected shoots serve as a source of new spores for further spread. The disease can be more severe in years with frequent rains coinciding with leaf production, providing favorable conditions for the fungal growth and dissemination of spores.
Symptoms
1 - Plants Health
• Cryptocline cinerescens infect plants, causing infected shoots to die, resulting in twig blight and dieback. The crown of the plant may experience general thinning in the year following infection. • Heavy infestations can lead to reduced tree vigor and an unsightly appearance. These impacts can weaken the overall health and aesthetic value of the affected plants.
2 - Soil Erosion and Ecological Consequences
• Cryptocline cinerescens has several impacts on the soil and environment. It increases the risk of soil erosion, especially in areas prone to heavy rainfall or slopes, due to the loss of tree roots. • Additionally, it alters the visual appeal of landscapes and disrupts habitat and food sources, resulting in reduced biodiversity and ecological balance. • Twig blight can also contribute to fire hazards and obstruct sunlight, affecting planned solar arrays.
Solutions
1 - Cultural Care
• Provide adequate cultural care to maintain tree health. • Ensure proper watering practices, especially during dry seasons. • Avoid excessive fertilization, which can promote excessive shoot growth and susceptibility to diseases. • Seek advice from certified arborists or tree care professionals for accurate diagnosis and tailored treatment recommendations.
2 - Pruning and Management
• Prune infected twigs during dry weather in the summer or early fall. • Make clean cuts in healthy tissue below infected twigs. • Proper pruning can help control the disease and prevent further spread. • Address any concurrent infestations, such as oak pit scales, which may worsen the damage caused by a pathogen. • Maintain good tree vigor and overall health to reduce susceptibility to disease.
3 - Systemic Fungicides
• Here are some commonly used fungicides for the control of oak twig blight (Cryptocline cinerescens): Mancozeb, Thiophanate-methyl, Propiconazole, Myclobutanil, Boscalid, and Azoxystrobin. • Consult with professionals for specific guidance on proper application and adherence to label instructions.
