Pests And Disease

Question 1

How can disease and pests affect yields

Question 2

What are nematodes ?

Answer 2

They are microscopic worms that attack the roots of the vines interfering with water and nutrient intake

Question 3

How can you deal with nematodes?

Answer 3

Prevention is better than cure
Sanitising the soil before replanting and using resistant rootstocks

Question 4

How do birds and mammals affect yields?

Answer 4

They consume large volumes of grapes.
Half eaten or crushed grapes can promote fungal diseases

Question 5

How can growers protect against birds and mammals?

Answer 5

Netting is the best option to prevent birds whereas protective fencing is needed to stop deer, wild boar or raccoons

Question 6

Insects - what do insects feed on in the vineyard?

Answer 6

Both grapes and leaves

Question 7

How can the grower treat the problem with insects?

Answer 7

Grower may choose to treat the problem with regular spraying of insecticides or more environmentally friendly techniques such as integrated pest management

Question 8

What is Downey mildew and what conditions does it thrive in?

Answer 8

Downey mildew is a fungal disease which affects the green parts of the vine

Question 9

What are the symptoms and side affects of Downey mildew?

Answer 9

Downey mildew appears as yellow dots on upper side of leaves and furry grey patches on underside of leaves.
It can cause leaves to drop prematurely as well as affecting inflorescences and young grapes reducing yields

Question 10

What is powderey mildew and what conditions does it thrive in?

Answer 10

It’s a fungal disease which attacks the green part of the vine including leaves and the grapes
It thrives in warm shady humid conditions

Question 11

What are the symptoms and side affects of powderey mildew?

Answer 11

It appears as a grey white powderey coating on green part of vine as well as leaves and grapes.
Grapes may shrivel, split and fail to ripen
Severe infections can cause leaves to dry up and fall off vine

Question 12

What is Grey rot otherwise known as?

Answer 12

Botrytis cinerea

Question 13

Where does grey rot thrive and what does it attack?

Answer 13

In damp conditions and it attacks the grapes

Question 14

What are the side affects of grey rot?

Answer 14

It taints the flavours of the grapes and in black grapes leads to colour loss

Question 15

How does grey rot turn to noble rot?

Answer 15

Noble rot is when white grapes in certain conditions are infected by botrytis and make sweet wines

Question 16

How can you control fungal dieases?

Answer 16

By spraying fungicides

Question 17

What fungicides do you spray to control powderey mildew?

Answer 17

Treated with sulphur based sprays

Question 18

What fungicides do you spray to control Downey mildew?

Answer 18

Bordeaux mix a copper based spray

Question 19

How is spraying using done?

Answer 19

By tractor

Question 20

Which climate is spraying needed more and why?

Answer 20

Maritime climate due to high levels of rainfall in growing season

Question 21

When and why should spraying stop?

Answer 21

Weeks before harvest to reduce harmful residues in the wine

Question 22

How else can fungal infections be reduced?

Answer 22

Appropriate canopy management
An open canopy allows airflow and evaporation. This also reduces the need for expensive chemical sprays

Question 23

What type of pruning can reduce the risk of fungal disease?

Answer 23

Trellised Vertical shoot positioning

Question 24

What other diseases are present in the vineyard?

Answer 24

Viruses are common - most don’t kill the vine but limit its ability to function which can reduce yields and quality

Question 25

How can growers treat viruses?

Answer 25

There are no cures or treatments and can only be eradicated by digging up the vine and sanitising the soil

Question 26

How are bacterial diseases spread throughout the vineyard

Answer 26

By sharpshooters which are small insects

Question 27

How can you treat bacterial diseases?

Answer 27

There are no cures or treatments. The only thing a grower can do is quarantine the vine and intercept the life of the sharpshooter which will prevent the spread. Once a vine is infected the only thing to do is dig up the vine and sanitise the soil