Pest and Disease Management

Question 1

What can explain the level of damage of a disease in a vineyard?

Answer 1

quantity/quality of inoculum (example. quality of downy mildew dependent on winter weather conditions)

multiplication rate (dependent on weather conditions)

susceptibility of vine (phenology, cultivar)

cultural practices

Question 2

What shape does fungal disease development take on a graph?

Answer 2

an S shape

Question 3

How to manage fungal disease in a vineyard?

Answer 3

prophylaxis
chemical control
biological control
resistant varieties (4 available in France)

Question 4

What prophylactic measures help manage fungal diseases?

Answer 4

Vigor control- shoot topping (except GM), leaf thinning, grass cover (only GM), fertilization management

Removal of unwanted shoots at the trunk of the base in spring (DM and BR)

Removal of primary inoculum (mummified berries, contaminated shoots) (BR)

Drainage (DM)

Question 5

What is most effective in reducing grey mold?

Answer 5

Leaf thinning early in season (at fruit set)

Question 6

Contact fungicides

Answer 6

No penetration of the product inside the plant
Leachable, will go away with rain
Newly formed organs are unprotected

Question 7

Penetrating fungicides

Answer 7

distribution in all treated organs
not leachable
Newly formed organs are unprotected

Question 8

Systemic fungicides

Answer 8

Distribution in all of plant by sap
not leachable
New formed organs are protected

Question 9

When to spray?

Answer 9

When the crop is susceptible

when the pathogen is able to cause damages

when the previous spraying is no longer effective or washed out

Question 10

How to combat fungicide resistance?

Answer 10

Alternate type of fungicide and don’t use the same mode of action two times in a row

Question 11

Which element is active against downey mildew?

Answer 11

copper

Question 12

Which element is active against powdery mildew?

Answer 12

sulfur

Question 13

Why are there no specific sprayings for black rot?

Answer 13

If you combine downey/powdery mildew fungicides you will also treat BR if you choose properly.

Question 14

All fungicides in organic viticulture are ________ fungicides.

Answer 14

contact

Question 15

What is the copper restriction?

Answer 15

28 kg/ha for 7 years

Question 16

Few fungicides have _____________ properties?

Answer 16

curative

Question 17

Should spraying be based on curative positioning?

Answer 17

No, it should be preventative. There are few curative fungicides and they have an effect limited with time. (risk of resistance)

Question 18

Antisporulant treatments

Answer 18

Destroy fruiting bodies of mycelium (but are not recommended)(risk of resistance); sweet orange oil

Question 19

Preventative positioning

Answer 19

Spray before infection; all fungicides are effective

Question 20

What form of sulfur is curative for powdery mildew?

Answer 20

powder

Question 21

Why is grey mold difficult to manage?

Answer 21

no relation between latent botrytis and grey mold rate at harvest: strong relationship of post-veraison weather conditions; no risk forcasting model available

Question 22

Grey mold favors:

Answer 22

grape berry moths
wounds
berry splitting

Question 23

What is the most serious virus in viticulture?

Answer 23

Grapevine Fanleaf Virus

Question 24

What transmits grapevine fanleaf virus?

Answer 24

nematodes

Question 25

How long does grapevine fanleaf virus last?

Answer 25

a lifetime

Question 26

What are the nepoviruses associated with grapevine fanleaf virus?

Answer 26

GFLV (grapevine fanleaf virus) ArMV (Arabis Mosaic virus)

Question 27

What makes controlling nematodes hard?

Answer 27

They have a long life span (can survive up to 7 years without food) They have many host plants They reproduce by parthenogenesis

Question 28

How do you manage nematodes?

Answer 28

Devitalize and remove roots Cultural practices (tillage, fallow period) 'Suspressive plants': oat, alfalfa, vetch Resistant rootstock: Nemadex

Question 29

What are the grapevine yellows?

Answer 29

a group of bacterial contaminations characterized by yellow and red leaves including flavescence doree and bois noir.

Question 30

What spreads flavescence doree?

Answer 30

leaf hoppers

Question 31

How many generations of the flavescence doree leaf hopper are there per year?

Answer 31

once with a long hatching period between the beginning of May to the end of June.

Question 32

What spreads Pierce's disease?

Answer 32

Sharpshooters, with varying lifecylces

Question 33

What do the symptoms of Pierce's disease mimic?

Answer 33

water stress

Question 34

Will symptoms of trunk diseases appear every year?

Answer 34

No

Question 35

What is the egg incubation time of grape berry moths?

Answer 35

5 to 15 days

Question 36

Should spraying decisions be based off egg counting or larvae counting of grape berry moths?

Answer 36

larvae counting; eggs are hard to indentify

Question 37

When will insect traps have bad efficiency?

Answer 37

during bad weather conditions; so have a net of traps with neighbors in the region

Question 38

What is the purpose of egg counting?

Answer 38

For knowing when to position treatments

Question 39

What is the purpose of trap monitoring?

Answer 39

For determining if counting should occur

Question 40

What are the egg stages of grape berry moths?

Answer 40

Fresh egg (a few days old) Yellow egg Blackhead egg (just before hatching)

Question 41

When you find the max trappings during a flight, how long should you wait to do larvae counting?

Answer 41

3-4 weeks

Question 42

What is the grape berry moth threshhold?

Answer 42

5 glomerulus/100 bunches

Question 43

Are insecticides more effective on young larvae or old larvae?

Answer 43

young larvae

Question 44

How much is mating disruption?

Answer 44

200-250 euros/ha

Question 45

What are the kinds of chemical insecticides?

Answer 45

insect growth regulators/inhibitors neurotoxins

Question 46

When spraying insecticides should you spray on the whole canopy?

Answer 46

No; also don't mix fungicide treatments because you are not spraying the whole area

Question 47

"choc", action

Answer 47

duration of efficiency of insecticide; range of time you can spray insecticide; maximum of age affected by insecticide. Ex. if you have 'choc' of 1 day, you have to position it precisely at the stage for good efficiency

Question 48

What is the glomerulus?

Answer 48

When several flowers are kept together due to silk nest of grape berry moths.

Question 49

Why are parasites still inoperative at this time?

Answer 49

They are still not well understood in how to introduce them (nests?). Plus you must introduce a lot to be infected.

Question 50

What are the generalist beneficial insects?

Answer 50

ladybugs, mites, harvestmen, lacewings, heteroptera, spiders

Question 51

What should you not use to preserve beneficial insects?

Answer 51

neurotoxins

Question 52

How often should you renew organic pesticides?

Answer 52

every 20 mm of rain

Question 53

What is the pesticide approval process in Europe?

Answer 53

1. European approval for active substance 2. National approval for formulated product

Question 54

What is included in the approval process?

Answer 54

classification for toxicological, ecotoxicological, and environmental hazards hazard and precautionary statements preharvest interval interval between applications distance to water zones (nontreated areas)

Question 55

What is a formulated product?

Answer 55

1 or several active substances with coformulants

Question 56

What is included in the registration?

Answer 56

1 dose for 1 target on 1 crop, under specific proper conditions

Question 57

What is the restricted entry interval?

Answer 57

the duration in which you can not go into the vineyard after spraying; depends on hazard statement minimum is 6 hours (12 hours in Bordeaux) closed environment (8 hours) irritant products for skin and eyes (24 hours) sensitizing products (48 hours)

Question 58

What is the bee hazard mention?

Answer 58

you can spray during flowering during times when bees aren't there normally you can't use insecticides during flowering so you don't arm pollinators (for crop or if you have flowering grass cover; must destroy flowers first)

Question 59

Can you mix any products?

Answer 59

No; you must check first

Question 60

What regulations are in force with spraying?

Answer 60

wind speed <20 km/hr; cannot spray max copper 28 kg/ha for 7 years no noise pollution from 22:00 to 6:00 prefectural orders to preserve places hosting vulnerable people

Question 61

What are good conditions for the use of pesticides?

Answer 61

do not spray in high wind, high heat, or under wind spray before the rain respect the renewal rates of the products shoot or leaf top before spraying respect dying and penetration time (between 1 to 4 hours) adjust volume of mixture to vegetation surface if possible use recovery panels for early treatments control sprayer and spray quality (avoid wasting product/check nozzles)

Question 62

Why should you not spray for grape berry moths and grey mold at the same time as other treatments?

Answer 62

Because you are only spraying the bunches and not the canopy