Phomopsis blight is caused by the fungus Phomopsis vexans, and is a major disease of eggplant. Tomato and pepper are not affected by Phomopsis blight. The disease occurs when spores are released from a fungal fruiting body (pycnidia) and dispersed by splashing rain, insects, and contaminated equipment. Spores germinate rapidly when free moisture is present on leaves, stems, or leaves. The fungus survives between eggplant crops on and in crop debris, seeds, and soil.
Phomopsis blight can cause disease on eggplant leaves, stems, and fruit. P. vexans also can cause a seedling damping-off. Leaf spots first appear as small (less than 0.4 inches) gray to brown lesions with light centers. Lesions often become numerous and cover large areas of leaves. Severely infected leaves become torn, yellow and wither. Small black dots, the fungal fruiting bodies called pycnidia, are often apparent on older leaf, stem, and fruit lesions. Stems and branches may develop dry, brown, cracked and sunken cankers. If a canker develops at the base of a stem, it can girdle and kill the stem. Fruit lesions are sunken, discolored, and soft with a surrounding margin of black fruit bodies. If conditions become dry, infected fruit become shriveled, dry, and form black mummies.
No biological control strategies have been developed for Phomopsis blight.
Plant only high quality seed and transplants free from the Phomopsis blight fungus. Plant resistant varieties if available and suitable for your marketing needs. Practice a three-year or longer crop rotation between eggplant crops. Destroy crop residues after harvest by deep plowing to reduce over wintering of the pathogen. Promote rapid leaf drying by timing irrigations to end before dusk, spacing plants farther apart in and between rows, and planting parallel to the prevailing wind direction.
If disease is identified in the field treatment with a recommend fungicide is advisable. Newer fungicides such as Cabrio, Quadris, and Endura are registered for use on eggplant, but their efficacy against Phomopsis fruit rot is unknown. Fungicides are most effective when combined with cultural control strategies.
Product List for Phomopsis Fruit Rot (Phomopsis Blight):
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Pesticide |
Rate/Acre |
Application Frequency
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Remarks |
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Captan |
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Captan 50 |
2 lb |
3-7 days |
4 day REI |
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Copper Fungicides |
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Champ Dry Prill |
2 lb |
7-10 days |
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Champ Formula 2 |
2 pt |
7-10 days |
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Copper-Count-N |
4 pt |
7-10 days |
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Cuprofix Disperss |
2.5-6 lb |
7-10 days |
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Kocide 101 |
1.5-3 lb |
5-7 days |
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Kocide DF |
1.5-3 lb |
5-7 days |
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Kocide 4.5LF |
1-2 pt |
5-7 days |
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Kocide 3000 |
0.75 lb |
7-10 days |
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Nordox |
2-4 lb |
7-10 days |
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Top Cop + S |
4 pt |
7-10 days |
1 day PHI |
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Tri-Basic Copper |
3 lb |
7-10 days |
1 day PHI |
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EBDC |
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Maneb 75DF |
1.5-2 lb |
7-10 days |
Maximum of 14.9 lbs; 5 day PHI |
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Maneb 80W |
1.5-2 lb |
7-10 days |
Maximum of 12.8 lbs; 5 day PHI |
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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. |
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Categories: Eggplant, Pepper, Tomato, Disease, Phomopsis Fruit Rot, Phomopsis Blight
Date: 04/01/2007