Leaf Spot (Cercospora fungus) on Sweet Basil

Leaf Spot (Cercospora fungus) on Sweet Basil

Leaf Spot (Cercospora fungus) on Sweet Basil

Cercospora is a genus of fungi encompassing over 1200 species.  Many of them can affect plants in your garden.  Booooo!  It usually looks pretty similar to the photo above but it does change a bit depending on the species/plant.  Light centered irregular spots with a darker halo is a pretty common look. The species that attacks Basil is Cercospora ocimicola.

Fungal spores overwinter from previously affected plant debris in the area, can be carried in on the wind, or can come by way of infected plants or seeds.  I believe the spores can survive at the soil surface as well.  I haven’t found anything that states this emphatically, but I have found plenty of information stating Cerospora can’t survive being buried.  Further, one of the recommendations to reduce Cercospora incident is not to splash water onto the plant from the soil when watering.  The overwintered spores require only warmth and moisture to do their thing.  Somewhere between 68 and 95 degrees Fahrenheit (20 – 35 C) will do.  When the spores get wet they germinate. If conditions stay favorable then the fungus thrives.

There isn’t a cure but there are preventatives you can take to keep it from starting or spreading.   Try to keep the leaves dry.  Overhead watering should be avoided, especially when it’s humid.  Rain could make things worse.  A good layer of mulch will keep you from splashing soil onto the leaves while watering.   Overcrowded plants trap humidity due to poor airflow so they may be at greater risk.  If overcrowded plants become infected they will most likely spread the disease faster due to infected leaves brushing against each other.

Its http://amerikabulteni.com/category/haberler/new-york/ cheapest cialis mechanism of action is effective and result is always guaranteed. Many men suffer buy viagra 100mg from some form of erectile dysfunction or impotency. In addition to minerals, also contain magnesium, copper, sildenafil tablets 50mg manganese, phosphorous, potassium, iron, sulphur and calcium. ED is curable and you can get rid of your ED able it temporarily if you choose to viagra cialis india. So you got Cercospora.  Now what?

Remove affected leaves immediately and don’t touch other leaves while doing it.  The leaves you remove should be buried deep, burned or removed from your property so you don’t spread spores around.  Clean any tools that come in contact with affected plant parts.  Watch out where you put your grubby fungus fingers too.  Don’t touch healthy plants until you’ve washed your hands.  Plants of another genus should be ok…. I’m pretty sure you can’t spread Cercospora from your basil onto your tomato.

Some people use fungacide but I have no experience in that area so I’m not much help. I think copper is considered organic.

Well, that’s about what I know about all of it.

About Stalk of Fennel

I like to grow stuff I can use!
This entry was posted in Disease & Problems, Herbs, Plants, Water and tagged , , , . Bookmark the permalink.

One Response to Leaf Spot (Cercospora fungus) on Sweet Basil

  1. Jeff says:

    Thank for the excellent explanation, alot is avialable on the web on this little known topic. I grow and dry several dozen basil plants every year and give it away. This year my crop was destroyed by the fungus. Fortunately alot of late summer rain has made a great parsley and oregano crop this year.