Powdery Mildew Final Quiz

1

What non-fungicide control method can be used to help reduce powdery mildew pressure? *

Increased irrigation.

Increased fertilization.

Monitoring canopy temperature.

Canopy management techniques that open up the canopy and allow better airflow.

2

How do the temperature preferences of grapevines and powdery mildew compare? *

Powdery mildew and grapevines have similar temperature preferences, but powdery mildew can’t handle hotter temperatures.

Powdery mildew and grapevines have similar temperature preferences, but powdery mildew can’t handle colder temperatures.

Powdery mildew grows better in temperatures colder than grapevines.

Powdery mildew grows better in temperatures hotter than grapevines.

3

How does Powdery Mildew get its nutrients? *

Secrete enzymes to kill and digest cells and absorb the nutrients.

Use a stylet to puncture into the xylem tissue and drink the nutrients.

Use a haustorium to puncture individual cells and drink the nutrients out of them.

4

What type of reproduction can Powdery Mildew use? *

Asexual/clonal reproduction

Sexual reproduction

Powdery mildew uses asexual/clonal reproduction during the growing season and sexual reproduction during the winter/dormant season.

Powdery mildew uses sexual reproduction during the growing season and asexual/clonal reproduction during the winter/dormant season.

5

What cool new technology will be coming to a vineyard near you… in the not-too-distant future? *

New varieties with increased disease resistance

A new spray that uses RNAi to turn off important genes within the Powdery Mildew

Both A and B

A magic unicorn that will take all your troubles away from you… including Powdery Mildew

6

Where can you get unbiased information on the effectiveness of Powdery Mildew fungicides in California? *

Talk to your local PCA.

Talk to your local extension rep.

Talk to your local pesticide supplier.

Visit the Eskalen lab webpage for their yearly powdery mildew spray trial updates.

7

What factors are important when discussing disease outbreaks? *

Host (grape) susceptibility/resistance

Pathogen (powdery mildew) strain/type

Environmental (weather) conditions

All three factors are equally important and only when a susceptible host, powdery mildew spores and permissive environmental conductions come together do you get a disease outbreak.

8

How should you decide what fungicide to use when treating powdery mildew? *

Go with what worked last year.

Go with what’s new.

Don’t use one, always rotate, rotate, rotate.

9

What type of data is needed to calculate the Powdery Mildew Risk Index *

Maximum and Minimum daily temperatures.

Just Maximum daily temperature.

Just Minimum daily temperature.

Need to know the temperature across the entire day.

10

What does a higher score on the Powdery Mildew Risk Index mean for your spray program? *

You should increase the time between your Powdery Mildew fungicide applications.

You should decrease the time between your Powdery Mildew fungicide applications.

You should increase the amount of fungicide applied to your vineyard.

You should decrease the amount of fungicide applied to your vineyard.