| Crown Rot & Seedling Blight: Fusarium oxysporum f.sp. asparagi, Fusarium proliferatum, Fusarium verticillioides |
Symptom:
- Crown rot coupled with winter injury can reduce newly seeded and established asparagus plantings by up to 50% or more in a year.
- Infected seedlings will exhibit stunting, yellowing and wilting of the foliage as the primary roots are rotted off.
- Established plants will produce spindly spears in the spring. Shoots become dwarfed, wilted and brown in color.
- Later in the season one or more shoots per crown appear stunted, turn yellow, then can wilt and die. Roots are also rotted and discolored.
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Yellow plant |
Brown and mushy roots |
Rotten root |
Oval-shaped lesions |
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Identification of pathogen:
- The disease is caused by complex of Fusarium oxysporum f.sp. asparagi, Fusarium proliferatum and Fusarium verticillioides
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Fusarium oxysporum f.sp. asparagi |
Fusarium oxysporum asparagi conidia |
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Management:
- The disease is seed- and soil-borne. New plantings should be established on soil (well-drained, sand-loam soils are preferred) where asparagus has not been previously grown for at least five years.
- Use strong healthy plants (1 year crowns) to start a plantation and to ensure good plant health by following good planting and growing procedures such as ertilization, insect and weed control and avoid over harvesting.
Source:
Images: http://www.omafra.gov.on.ca/IPM/english/asparagus/diseases-and-disorders/fusarium.html
Plate and microscopic images: http://francescofiume.xoom.it/fiumefrancesco/Asparagus.html
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