Hardiness Zone: 6b
Angela from Painesville, OH
If you don't see signs of insects, my guess would be that it is some type of bacterial leaf spot. Incidentally, tomatoes are also susceptible to bacterial leaf spot and can act as hosts for this disease.
Symptoms usually appear as small yellowish-green spots on the plant's leaves. As the spots mature, they become brown to black and sunken. Tissue in the center of the spots often dries and breaks away, giving the leaves a "bullet hole" appearance. The edges and tips of leaves may die, then dry and break away, causing leaves to appear ragged and eventually drop off. Bacterial leaf spot can also cause brown, scab-like spots on the peppers themselves.
This pathogen usually starts with infested seeds (surviving up to 10 years on dried seeds). It can also lay waiting in the soil on dead plant debris (for up to 6 months) and spread from plant to plant by way of splashing water.
The first line of defense in controlling bacterial leaf spot is to make sure you start with pathogen-free pepper seeds and transplants. Avoid watering plants from overhead to reduce splashing and practice crop rotation by rotating non-host crops like corn and beans every few years. Spray your pepper plants with copper as soon as symptoms appear to prevent further spread of the disease. Seeds can be pre-soaked in a 10% bleach solution. Discard severely infected plants, including all plant debris. Don't compost this material, toss it in the garbage.
About The Author: Ellen Brown is an environmental writer and photographer and the owner of Sustainable Media, an environmental media company that specializes in helping businesses and organizations promote eco-friendly products and services. Contact her on the web at http://www.sustainable-media.com
Here are the recent answer to this question.
By MrsJim (Guest Post)10/06/2008
Ellen mentioned spraying them with copper. What exactly is that and where is it purchased? Thanks
By Angela (Guest Post)10/02/2008
THANK YOU! I actually do have another question though... do I have to get rid of the pots these plants were in also?
By Tiersa (Guest Post)07/20/2008
Have you contacted your extension office yet? They are a great resource (especially since your tax-dollars pay for it) and will let you know what is wrong with your plants!
By Jazzylazzy (Guest Post)07/17/2008
I can't tell from the picture if this is caused by overwatering and not letting the soil dry between waterings or if you have a bug called scale. Scale is a small brown bug that you can easily take off the plant. As they travel and multiply they leave a sticky residue. There are houseplant insecticides you can buy that sometimes work. Try looking online at other pictures to compare with.
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