Chapter 8 - Part 2: Pests Flashcards Preview

WSET Diploma D1 > Chapter 8 - Part 2: Pests > Flashcards

Flashcards in Chapter 8 - Part 2: Pests Deck (10)
Loading flashcards...
1
Q

What is Phylloxera?

A

insect that feeds and lays eggs on roots. It damages the roots and reduces the uptake of nutrients and water. The damaged roots also become vulnerable to bacteria and fungi
Leads to death of the vine

Signs that a vineyard has an infestation:
vines die of drought in patches
vine roots are covered with the insects surrounded by yellow eggs
swellings on older roots
pale green leaf galls on the under-surface of leaves
slow, stunted growth, leaf yellowing in ~3yrs
plant dies in ~5yrs

mostly transported by humans - by equipment, water, dirt on shoes

2
Q

Phylloxera Management

A
  1. grafting onto American rootstock - V. berlandieri, V. riparia, V. rupestris. They form hard, corky layers that surround the eggs, sealing the wounds and preventing invasion by bacteria or fungi
  2. Single American varieties have little lime tolerance so rootstock hybrids between the various American species was created. Also done for other problems - nematodes, extreme soil pH, water stress, salinity, vigor
3
Q

What are nematodes?

A
microscopic worms that feed off vine roots
Reduces yield, vigor
transmits diseases (fanleaf virus is spread by dagger nematode)

Most common: root-knot nematode and dagger nematode

They are either already in the soil or spread by unclean nursery stock, irrigation water, or vehicles.

Once present can only be managed. not eliminated

4
Q

Nematode Management

A
  1. fumigate soil but mostly banned now
  2. plough in a cover crop of mustard plant that works as a biofumigant
  3. use nematode-resistant rootstock ie Ramsey and Dog Ridge
5
Q

What are Grape Moths?

A

they feed on flowers and grapes
Many have several generations per season so attack from flowers in spring to grapes in fall
The wounds make them vulnerable to bacteria and fungi
causes significant crop loss

6
Q

Grape Moth Management

A
  1. biological controls
    a. the bacterium Bacillus thuringiensis produces substances toxic to moths
    b. sexual confusion with pheromone capsules
    c. natural predators - wasps, spiders
  2. insecticides
7
Q

What are spider mites

A

feed on the surface cells of leaves leading to discoloration, reduction in photosynthesis, delayed ripening, and reduction in yields

thrive in dusty conditions

most damaging to vines already water stressed

8
Q

Spider Mites Management

A
  1. use water sprinklers, cover crops, or mulch to reduce dust
  2. encourage predatory mites that feed on spider mites
  3. pesticides
9
Q

Bird Management

A
  1. netting
  2. bird scarers or noises - must be rotated regularly
  3. falcons
10
Q

Mammal management

They eat shoots, grapes, and leaves

A

Fencing