Basil Fungus Spreading
Wow! That just sucks. So far no sign of it in my beds and I haven't heard anyone else complaining. What helps slow fungus and mildew from spreading is to water beneath the leaves, keeping the vegetation as dry as possible. We use wand waterers, having lost other crops to mildews and such in the past. Doesn't always prevent it but definitely slows down the spread.
My basil caught it this year. Daconil didn't help at all but I did spray nearby plants so that they were protected. I have a small garden with the typical tomatoes, peppers etc. and I was taking no chances so I yanked it and tossed it after a few days. It's not worth letting it spread to other nearby plants, so I caution those who try to wait it out or simply "slow down the spread." I'd rather lose one plant immediately and completely instead of losing several slowly.
re: Shaw Oliver
Yellowing leaves was the first clue, than there were tiny black spots on the underside of the leaves that continued up the stalk (ground up is how is spread). There wasn't a gray/white powdery-ness like there is with powdery mildew but maybe that's because I didn't let it sit around that long.
This is almost exactly the way mine looked but my leaves were far more yellow: http://www.longislandhort.cornell.edu...
re: Shaw Oliver
How early did you catch it? Were you experiencing leaf drop by the time you pulled the plants?
My Thai basil has some yellowing, but I think that might be related to nutrition. More alarming are the shoots which have turned black and stopped producing leaves. The picture you attach, however, looks very similar to the disease that is decimating my peppers and tomatoes, but does not respond to Safer's fungicidal soap.
here's some more info, from last year, but relevant this year, too:
>>"" Basil - northeast region
Date: 26 Jun 2009
Source: Horticulture News, Cornell University [edited]
< http://blogs.cornell.edu/hort/2009/06... >
A disease affecting gardens and farms in the northeast is a relative
newcomer -- basil downy mildew. In 2008, the disease was severe on
many of the region's farms. It often goes undetected because the major
symptom -- leaf yellowing -- looks similar to nutrient deficiency. The
downy spore-bearing structures only appear on the undersides of leaves.
[Byline: Via Meg McGrath]""<<<
i'm looking for a photo.... maybe this will come through: http://www.google.com/imgres?imgurl=h...
here's the photo accompanying the AP story: http://www.msnbc.msn.com/id/38411332/...
I have had a trerrible time with Basil. I had plants that I bought and transplanted into large planters, take off and start growing. One by one the plants would lose the vibrant green color, turn a dull lusterless green and within 2 or 3 days wilt and die. I think my problem was a type of Fusarium. I would not lose all the plants, so I saved seeds from the healthy plants and replanted, and did not buy any seedlings. Now I am in the 4th or 5th cycle of using only the seeds from my plants, and have not had a wilted plant in about 8 months. I do not know if this is a coincidence or maybe the problem was bred out of the plants. I did change soil and disinfect the planters that I use. So far so good!!!!