Fusarium crown and root rot, or crown and foot rot, means death for asparagus.
Fusarium causes several crown and root diseases. This one attacks asparagus. Heavy soil, poor drainage, over-harvesting, and insect feeding create the perfect habitat for this ubiquitous fungi.
Three different forms of the Fusarium fungi cause this fungal disease of asparagus. This trio of Bad Guys (Fusarium oxysporum f. sp. asparagi, F. verticilliodes, and F. proliferatum) colonize the roots, crown, and xylem tissue.
Symptoms of Fusarium crown and root rot
Asparagus plants infected with the Fusarium fungi decline over time. At first, you may see one or more stunted, bright yellow ferns. Do not ignore this bright yellow warning if you want to save your asparagus patch. Wilting is also common. If you look at the crown area, you will see reddish-brown discoloration. At this point, pull the plant out of the ground for a closer inspection.
Cut open the crown or below-ground area of the plant to see if sunken reddish-brown lesions are visible. Feeder roots will probably rot off completely, though any remaining tendrils will have the same reddish-brown discoloration seen elsewhere.
Unfortunately, these fungi can survive in the soil indefinitely and are everywhere. The disease can move around on equipment, seeds, shoes, and tools. Choose seeds and seedlings from reliable sources. This disease can occur anywhere underground. Very often, insect feeding creates points of entry for these fungi. Asparagus miners are a common culprit.
Controlling Fusarium crown and root rot
Environmental conditions that keep plants healthy also improve their ability to prevent these fungi from entering, so avoid water stress and feed plants regularly with top dressings of aged compost. [Asparagus plants are very heavy feeders.]
Infected plants should be dug up, roots, soil, and all, and disposed of in the trash.
Remember, perennial asparagus can provide you with many years of delicious spring and autumn spears, so don’t let these pathogens stop you from trying to grow your own!
You can grow a surprising amount of food in your own yard. Ask me how!
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