Eggplant, Pepper, and Tomato

 

Frogeye Leaf Spot (Cercospora Leaf Spot)

 

Howard F. Schwartz and David H. Gent

 

 

Identification and Life Cycle

Frogeye leaf spot is a disease of pepper caused by fungus Cercospora capsici.  The disease is most damaging in tropical and subtropical environments, but occurs occasionally in the western U.S.  Frogeye leaf spot is favored by high temperatures (86 to 95º) and abundant moisture.  Infection occurs when spores land on and directly penetrate leaves through natural openings.  Spores are disseminated by wind, splashing water, or by contaminated equipment.  The pathogen is thought to survive between pepper crops in association with crop debris and possibly seed.

 

Plant Response and Damage

Frogeye leaf spot symptoms first appear on leaves, petioles, and stems as small, round, water-soaked spots.  These spots develop into lesions with a light brown to white interior and a brown to red to purple border.  Older lesions may have concentric rings of water-soaked areas and dark rings.  Lesions range in size from 0.1 to 0.5 inches, and become brittle and crack as they age.  Stems can become girdled by a single elongated stem lesion.  The disease is of minor importance in the High Plains region in most years.

 

Management Approaches

 

Biological Control

No biological control strategies have been developed for frogeye leaf spot.

 

Cultural Control

Practice a three-year or longer crop rotation between pepper crops.  Deeply incorporate crop residues to reduce pathogen survival between seasons.  Varieties differ in their susceptibility to frogeye leaf spot, but the reaction of most varieties is unknown. 

 

Chemical Control

Fungicides are rarely if ever required to control frogeye leaf spot in the High Plains.  If disease is confirmed, a regular fungicide spray program should be initiated.  Newer fungicides such as Flint, Quadris, Cabrio, and Tanos may suppress or control frogeye leaf spot, but are not registered specifically for this disease.

 

Product List for Frogeye Leaf Spot:

Pesticide

Rate/Acre

Application Frequency
(days)

Remarks

Captan

Captan 50

2 lb

3-7 days

4 day REI

Copper Fungicides

Champ Dry Prill

2 lb

7-10 days

 

Champ Formula 2

2 pt

7-10 days

 

Copper-Count-N

4 pt

7-10 days

 

Kocide 101

1.5-3 lbs

5-7 days

 

Kocide DF

1.5-3 lbs

5-7 days

 

Kocide 4.5LF

1-2 pts

5-7  days

 

Kocide 3000

0.75-1.25 lb

7-10 days

(for pepper)

Nordox

2-4 lb

7-10 days

 

Top Cop + S

4 pt

7-10 days

1 day PHI

Tri-Basic Copper

3 lb

7-10 days

1 day PHI

EBDC

Maneb 75DF

1.5-2 lb

7-10 days

Maximum of 12.8 lbs; 5 day PHI

Maneb 80W

1.5-2 lb

7-10 days

Maximum of 12 lbs; 5 day PHI

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

 

Categories: Eggplant, Pepper, Tomato, Disease, Frogeye Leaf Spot, Cercospora Leaf Spot

Date: 04/02/2007