Spinach

Anthracnose

Howard F. Schwartz and David H. Gent

Identification and Life Cycle

Anthracnose of spinach is caused by the fungus Colletotrichum spinaciae.  The disease cycle is initiated by spores disseminated by wind and splashing irrigation and rainwater. The disease is most destructive at temperatures between 79 to 86º F, with abundant moisture. The fungus overwinters in seed and infested crop debris.

Plant Response and Damage

Anthracnose symptoms initially appear as small, dark olive-colored water-soaked spots. As the spots enlarge, they become tan in color. Under disease favorable conditions, lesions become larger and more numerous, eventually coalescing and killing entire leaves and petioles.  If weather conditions become less favorable for disease, severely infected leaves will drop from the plant and new foliage will appear relatively free from infection.

The disease reduces both spinach yield and quality.

Management Approaches

Biological Control

No biological control practices have been developed for anthracnose.

Cultural Control

Plant high quality spinach seed free from the anthracnose pathogen. Practice a three-year or longer rotation to nonhosts, such as small grains or corn.  Avoid overhead irrigation, especially during humid, cloudy weather.  Deeply bury crop residues soon after harvest to reduce pathogen survival and overwintering.  Eliminate volunteer spinach.

Chemical Control

Chemical controls are most effective when integrated with sound cultural control practices.

 

Product List for Anthracnose:

Pesticide

Product per Acre

Application Frequency (days)

Remarks

Copper Fungicides—not all formulations available are listed

Champ DP

1.33-2.66 lb

7-10 days

Can cause leaf flecking

Copper-Count-N

3 pt

7-10 days

Can cause leaf flecking

Cuprofix Disperss

2.5-4 lb

7-10 days

Can cause leaf flecking

Kocide 2000

1.5-2.25 lb

7-10 days

Can cause leaf flecking

Kocide 3000

0.75-1.25 lb

7-10 days

Can cause leaf flecking

Nordox

2-3 lb

7-10 days

Can cause leaf flecking

Nu-Cop 3L

1.33-2.66 pt

7-10 days

Can cause leaf flecking

Tri-Basic Copper

4 pt

 7-10 days

 1 day PHI

Neem

Trilogy

2 pt

7-14 days

Maximum of 2 gallons per season; 0 day PHI

Potassium Bicarbonate

Armicarb 100

2.5-5 lb

5-14 days

Apply in at least 20 gallons per acre; 0 day PHI

Strobilurin

Amistar

2-5 oz

5-14 days

Maximum of 4 applications; rotate with a fungicide with a different mode of action; 0 day PHI

Quadris

6.2-15.4 fl oz

5-14 days

Maximum of 4 applications; rotate with a fungicide with a different mode of action; 0 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: Spinach, Diseases, Anthracnose

 

Date:  04/01/2007