Plant Disease Basics 2 Flashcards
What are the three general symptoms of disease?
-Weekened or killed tissue.
- Abnormal in cell growth
- Whole plant apperance: Blight, stunted, dwarfing, wilts.
Do all disease symptoms spread?
No. They can either be localized (stick to one area) or systemic (spread throughout the plant).
What are primary and secondary symptoms?
Primary symptoms are at the infectious site and result in a direct response to the pathogen.
Secondary symptoms are a result of primary symptoms ex—wilting, chlorosis, etc.
What is Blight?
It is a rapid decline of different parts of the plant. Parts of the plants start dying off.
What kind of pathogen causes blight?
Bacteria
What kind of pathogen causes leaf spots and fruit spots?
Bacteria
What are the signs of leaf spots and fruit spots?
legions in the leaves or fruit that have the yellow halo around them.
What kind of pathogen causes canker?
Fungi
Where in the plant does canker occur?
Trunk, branches, and stems.
What are some signs of canker?
Cracked lesions on twigs, kills the weedy part of the tree.
What kinds of pathogens cause mosaic?
Viruses
What is the sign of mosaic?
Leaves look like a mosaic of green, light green and yellow.
What is the sign of corks?
Corky texture on plant roots.
Briefly describe the disease damping off.
This disease leads to the death of seedlings caused by the decomposition of roots and stems.
What kind of a pathogen caused damping off?
Fungi
What kind of a pathogen causes galls?
Bacteria, fungus, nematode or other organisms.
What are the signs of Galls?
Abnormal swelling or localized outgrowth.
What kind of pathogens cause soft rots?
fungi and bacteria
What is soft rots?
It is rotting of plant tissue as a result of fungal or bacterial infection. It affects the entire plant.
What are angular leaf spots?
They are similar to lesions on a leaf but the spots are angular.
What causes dieback?
Several abiotic factors like nutrition, water, weather and stem diseases, root diseases etc.
What is a sign of dieback?
The plant dies back from newest growth to oldest growth.
What disease is water soaking?
It is similar to angular leaf spots but instead of dead tissue, it looks like little water marks on the leaves.
What is a sign of scab disease?
Crstaceous lesions on all parts of the plant.
what is wilts?
Wilts is when the plant starts wilting due to lack of transport of water to the leaves. This can be caused by bacteria and fungi.
What is the sign of Witches brooming?
All nodes get pushed to the top of the plant and it starts to look like a broom.
What are the signs of leaf distortion?
Leaves being twisted, cupped rolled or deformed.
What kind of pathogen usually causes cupping of leaves?
Bacteria.
What is gummosis?
Gummosis is the disease where trees release gum like fluid that solidifies (Ambers)
What is necrosis?
Dead tissue
What is stunting?
Lack of growth
What is leaf scorch?
It is the degradation of leaves from the outside in.
What is Downy mildew?
It is a fungal disease in which fungus grows mostly along leaf veins. This is caused by oomycetes.
What is Powdery mildew?
It is a fungal disease in which white powder grows on the plant and resembles powder. This is mostly composed of mycelium.
What is mycelium?
Thread like growth on fungi.
What do bacterial strands look like?
They look like white strands/cotton.
What is ring rot?
Rotting that happens within a plant in the form of a ring.
When did the potato famine in Ireland take place?
1845-1850
What is the estimated cost of Fusarium Head Blight in Canada?
75 million dollars.
