Potato Diseases Flashcards
What is the difference between dispersal of late blight and early blight?
Late blight is dispersed through seed, wind, and soil, while early blight is dispersed through seed, wind, and plant debris.
What are the six types of potato diseases?
- Fungal Diseases
- Bacterial Diseases
- Viral Diseases
- Diseases by nematodes
- Herbicide Damage
- Environmental Disorders.
What kinds of diseases are late and early blight?
Fungal diseases
Which 4 crops are mostly affected by late blight and early blight?
Potato, Tomato, Eggplant and Peppers.
Which disease caused the Irish potato famine?
Late blight
What are some signs and symptoms of late blight?
lesions on leaves with fuzzy white growth. Discoloration on potatoes and mold. It can spread in storage.
List 5 pre-planting management options for late blight.
- Cultivar: Some cultivars are more resistant than others.
- Sit selection: Site with good air movement and drainage.
- Crop rotation: rotation of 2-3 years of non-host crops.
- Elimination of overwintering inoculum
- Only plant-certified seed tubers.
List 4 management options for late blight in established potato fields.
- Irrigation: reduce the time leaves are wet.
- Fertilization: do not use excessive fertilizer.
- Scouting for disease
- Fungicide application
List 2 harvest and storage management options for late blight.
- Destroy foliage to present inoculation.
- Infected tubers should be removed before storage.
What are the symptoms of early blight?
Small and dark necrotic legions on leaves. Water soaked legions on tubers, legions on stems.
Are there any resistant cultivars for early blight?
No
What are 6 management techniques for early blight?
- Select a late-season variety
- Irrigation: Do not keep the leaves wet.
- Scout fields for infection
- Rotate foliar fungicide.
- Rotate fields to non-host crops for at least 3 years.
- Irradicate weed hosts to reduce inoculum.
What kind of a disease is Leak (Wet Rot)?
Fungal Disease.
What are the signs and symptoms of leak?
Spongy, wet internal rot of tubers.
What kind of a pathogen is leak a result of?
Soil born pathogen.
When can leak cause significant losses?
During storage
What environment is favored by leak?
warm and moist conditions at harvest and early storage.
How does the pathogen that causes leak penetrate potatoes?
Through wounds and lenticles.
What kind of a disease is Black scurf?
It is a fungal disease.
What kind of defects does Black scurf have?
External defects.
What is the cause of dispersal in Black scurf?
Seed and Soil.
What are some signs and symptoms of Blackscruf?
Sclerotia on tubers, sprout infection, and root legions.
What does Blackscruf lead to?
Reduces emergence yield.
What kind of a disease is sclerotia stem rot?
Fungal disease
When is sclerotia stem rot most likely to be found in potatoes?
In fields close to canola or other susceptible crops. Also within wet canopies.
How can you manage this disease?
Fungicides
What kind of a disease is Black Leg and soft rot in potatoes?
Bacterial disease
What kind of a disease is Black Leg and soft rot in Canola?
Fungal disease
What is the common symptom between blackleg in Canola and blackleg in potato?
Wilting
What are the 4 methods of dispersal for Black leg?
Seed, Water, Soil and storage
What kind of defects does blackleg have?
Internal and external
At which stage does blackleg occur?
Can occur at any stage.
What are some signs and symptoms of Blackleg?
Inky, black decay that usually begins from seed piece, and wilting.
When is Blackleg most detrimental?
When in storage. infected tubers get soft rot and pass on the soft rot to all other potatoes under poor storage conditions.
Which environment does blackleg favor?
Warm and wet conditions
What are two ways to manage Blackleg?
Sanitation and Resistance in some varieties.
What kind of bacteria causes Bacterial Ring Rot?
Gram positive
Is Bacterial rig rot localized or systemic?
Systemic
What is the method of dispersal for bacterial ring rot?
Seed, water and soil
What kind of defects does bacterial ring rot cause?
External and Internal
What is the symptom of bacterial ring rot?
Ring formation on potatoes.
What kind of a disease is the common scab?
Bacterial disease.
What kind of a bacterial pathogen causes the common scab?
Soil-born
What are the ideal environmental conditions for the common scab?
warm, dry and soil pH of 5.2
What are the signs and symptoms of the common scab?
Corky raised or pitted legions
What are 3 ways to manage the common scab?
- Chloropicrin soil fumigation
- Scab tolerant varieties
- Rotation with small grains and alfalfa.
What are the 3 common potato viruses?
Potato virus A, Y and V.
How are the 3 potato viruses transmitted?
by Aphids
What is the sign of potato viruses?
Mosaics.
