Grapevine yellow disease Flashcards
1
Q
Symptoms
A
- delayed budding or no bud burst (dieback maybe end result)
- abortion of young bunches + dieback of bigger bunches
2
Q
How do Aster yellows work?
A
associated phytoplasmas move undisturbed from cell to cell in all directions to spread systematically in the phloem of all grapevine organs
3
Q
Leaves
A
- hardened or crackling leaves
- yellowing and copper-coloured reddening of leaves
- noticeable brittle and thicker, with leaves curling downwards
4
Q
Shoots
A
- shoots do not lignify
- short internodes
- premature dieback of shoot tips
- lead-grey colour on green shoot + longitudinal cracks along the surface
- dwarfed shoot growth with a tendency to form water shoots
5
Q
Anatomical reactions/change
A
Phloem infection may cause insufficient and disturbed physiological activities contributing to the shortening of the lifespan
