22.3 Evaluate economic impact of disease on production.

22.5 Evaluate the most economical and environmentally safe disease control and prevention methods.

22.8 Propose corrective actions needed to treat an infected field/organism.

• Identify economic impacts of plant diseases

• Investigate plant disease control measures

• Evaluate disease control and prevention methods

1. What are the economic impacts of plant diseases?

Lowers production (yield) and quality of crops

Decreases the supply of plant crops

Lower supply with sustained demand means higher cost to consumer

Plant diseases cost companies millions of dollars a year in prevention and control (including loss of crops)

The use of chemicals lowers the value of produce as “pesticide free” crops bring higher prices

Major Historic Event *Occurred in Ireland from 1845-1849

*One of the leading causes was “Blight” – a plant disease

*Estimated that 500,000 – 1million people died during the five year period

*Estimated 2 million refugees to Great Britain, United States, Canada and Australia

2. What are the three major categories of disease control measures?

• Cultural Controls -- Prevents the enemy attack

• Biological Controls – Using living organisms to help fight the enemy

• Chemical Controls – When all else fails, gas ‘em!

Sterile Soil (Price varies)

-Sterile soil may be bought or you may sterilize it yourself

Disinfect everything that touches the soil ($3/gallon of bleach)

- Includes liners, flats, tools, wheelbarrow and tabletops. A solution of 9 parts water and 1 part bleach

3.What are some simple things we can do to help prevent diseases?

3.What are some simple things we can do to help prevent diseases?

Close the door of the greenhouse (FREE!)

-It sounds simple, but it is true. This helps keep insects out and

keeps the environment controlled.

3.What are some simple things we can do to help prevent diseases?

Use insect traps such as“Sticky Cards” ($18/100 cards)

Yellow cards for aphids, fungus gnats, whiteflies and leafminers. Blue cards for thrips..

3.What are some simple things we can do to help prevent diseases?

Do not drop soil or plant debris on the floor. (FREE!)

-These materials serve as a starting point for many diseases.

Avoid bringing infested/infected plants into the greenhouse. (FREE!)

-An easy step that you can take that will pay off big in the long run.

3.What are some simple things we can do to help prevent diseases?

Do not drop soil or plant debris on the floor. (FREE!)

-These materials serve as a starting point for many diseases

3.What are some simple things we can do to help prevent diseases?

No food or drink in the GH (FREE!)

-This will only attract more insects and damage our plants in the long run

4. Biological controls include:

Insect Control

• Ladybugs for aphids

Application Rate(1 gallon per acre. $57.00 per gallon)

• Encaria Formosa for whiteflys

Application Rate (1-2 Per Sq/Ft every two weeks. $9.00 per 1,000)

4. Biological controls include:

• Mycostop

Contains living spores and mycelium of a selected strain of naturally occurring Streptomyces soil bacterium. The microbe deprives pathogen fungi of living space and nourishment by colonizing plant roots in advance of them.

4. Biological controls include:

• Mycostop

Application should begin at the time of seeding and should be repeated every 3 - 6 weeks. Apply at a rate of 5 grams ($28.50) per 540 sq/ft of "root area". (This is approximately 5 grams per 1,000 tomato plants).

5. What are some common chemical controls :

Fungicides

• Used to control fungi problems

5. What are some common chemical controls :

Insecticides Safer Soap ($19.95 per Quart)

Safer’s Insecticidal Soap is an environmentally sound method of getting rid of aphids, whitefly, and other potentially troublesome insects. With a pleasant odor and no residue, Safer’s Soap is approved by the FDA for same day harvest of food crops it is used on. Comes in concentrate form, just mix with water and apply!

5. What are some common chemical controls : Natural Insecticides

Pyrethrum

Pyrethrum is the extract of chrysanthemum flowers which provides for an “all-natural” defense against various insects.

5. What are some common chemical controls : Natural Insecticides

Neem Oil - Neem Oil is from the Neem Tree (native to eastern India & Burma). Concentrate is diluted in water before being sprayed. Control for insects AND fungal diseases.

6. Other Organic Control Methods : • Organic Emulsifiable Oils

• Increase pH

• Resistant Cultivars

• Sulfur

• Proper Environmental Controls

6. Other Organic Control Methods : • Organic Emulsifiable Oils

Used for fungal diseases

• Increase pH – increasing pH will control Fusarium Wilt

• Resistant Cultivars – purchase new varieties.

• Sulfur

• Proper Environmental Controls

6. Other Organic Control Methods : • Sulfur – controls mildews.

Duster machines are available.

• Proper Environmental Controls

Proper air circulation keeps fungal diseases from

forming

Humidity levels help control diseases.

Activity Each of you will work individually to

develop a disease management program for your greenhouse. You will be asked to offer solid, realistic solutions on how to both prevent and control Powdery Mildew, Tobacco Mosaic, Damping Off, Fusarium wilt, and blossom end rot.

Assessment Piece of cake!

7. Conclusions?

Disease cause losses by:

A.

B.

C.

D.

6. Conclusions?

Three types of disease control are:

1.

2.

3.

6. Match the Method of control with the Type of control?

1. Predator insects

2. Neem Oil

3. Shut the GH door

4. Keep Food Out

5. Keep Soil off floor

6. Encarsia Formosa

7. Safer Soap

8. Pyrethrum

A. Cultural Practice

B. Biological Practice

C. Chemical Practice