11 - Diseases Flashcards
What is the importance of understanding grapevine diseases and viruses?
Understanding grapevine diseases and viruses is crucial for effective vineyard management, as they can significantly impact vine health, yield, and wine quality.
What are the common symptoms of downy mildew in grapevines?
Common symptoms of downy mildew include yellow oil spots on leaves, white downy growth on the underside of leaves, and brown patches on shoots and berries.
How does powdery mildew differ from downy mildew in grapevines?
Powdery mildew forms a white powdery coating on leaves, shoots, and berries, whereas downy mildew causes yellow oil spots and white downy growth on the underside of leaves.
What is Eutypa dieback, and how does it affect grapevines?
Eutypa dieback is a fungal disease that causes dead canes, stunted shoot growth, and reduced yields. It can lead to vine decline and eventual death.
What are the main vectors of Grapevine Leafroll-associated Virus (GLRaV)?
The main vectors of GLRaV are mealybugs and soft scale insects, which transmit the virus as they feed on vine sap.
What is the impact of Fanleaf virus on grapevines?
Fanleaf virus causes distorted leaves, reduced vigor, poor fruit set, and lower yields. Infected vines often exhibit yellow vein banding and malformed shoots.
How can grapevine trunk diseases be managed?
Trunk diseases can be managed through good vineyard hygiene, removing infected wood, applying protective treatments, and selecting disease-resistant rootstocks.
What is the role of mycorrhizal fungi in grapevine health?
Mycorrhizal fungi form a symbiotic relationship with grapevine roots, enhancing nutrient and water uptake and improving overall vine health and resilience.
How does Botrytis cinerea (grey mold) affect grapevines?
Botrytis cinerea causes grey mold, which affects grape berries by creating brown lesions that can lead to fruit rot and spoilage, especially in humid conditions.
What is the significance of rootstocks in managing grapevine diseases?
Rootstocks play a crucial role in managing grapevine diseases by providing resistance to specific pathogens and pests, improving vine health and longevity.
What are the symptoms of Phomopsis cane and leaf spot?
Symptoms of Phomopsis cane and leaf spot include black lesions on shoots, leaves, and rachises, which can lead to reduced shoot growth and poor fruit development.
How can vineyard sanitation help prevent the spread of diseases?
Vineyard sanitation involves removing and destroying infected plant material, maintaining clean equipment, and implementing proper pruning practices to reduce disease spread.
What is the impact of the Japanese beetle on grapevines?
The Japanese beetle feeds on grapevine leaves, causing defoliation and reducing photosynthetic capacity, which can weaken the vine and reduce yields.
How can grapevine virus infections be diagnosed?
Grapevine virus infections can be diagnosed through visual inspection of symptoms, laboratory testing of leaf samples, and using diagnostic tools like ELISA and PCR.
What is the significance of crop rotation in managing grapevine diseases?
Crop rotation helps manage soil-borne diseases by disrupting the life cycles of pathogens, reducing their population in the soil, and improving soil health.
How can cover crops contribute to grapevine health?
Cover crops improve soil structure, enhance nutrient availability, reduce erosion, and promote beneficial soil organisms, contributing to overall vine health.
What is the role of systemic fungicides in managing grapevine diseases?
Systemic fungicides are absorbed by the plant and provide internal protection against fungal pathogens, helping to manage diseases more effectively.
What are the benefits of using disease-resistant grapevine varieties?
Disease-resistant grapevine varieties reduce the need for chemical treatments, lower production costs, and promote sustainable viticulture practices.
How does climate influence the prevalence of grapevine diseases?
Climate influences the prevalence of grapevine diseases by affecting temperature, humidity, and rainfall patterns, which create favorable or unfavorable conditions for pathogen development and spread.
