Damping off is term used to describe under soil, soil level and above soil rot and decay cause by fungus growth. It is able to attack plants at all stages of the growth cycle including seeds and is equally destructive at each.
Rot caused by fungus at or below soil level is usually fatal though it may be possible to cut surviving plant tissue above the decay and propagate.
Symptoms and Damage:
Infected seeds will usually rot below ground producing no plant which is referred to as pre-emergence damping off. If a seedling has sprouted and suddenly withers and dies or just outright collapses it has suffered a post-emergence damping off.
Mature plants are no safer suffering from root rot below ground which cause leaf drop starting with the oldest leaves, it will also experience stunted growth , wilting and rotted black roots. Severe cases may involve the stem of the infected plant turning black and slimy.
Fungi seem to thrive in warm and moist environments with little to airflow. A neutral pH between 6 and 7.5 are also needed, unfortunately this is also the range for the regular house plants to grow.
Prevention and Control of Damping Off
There are many benefits to avoiding chemicals when dealing with plant diseases. The harsh chemicals in some fungicides may cause more harm to an already injured plant not to mention the possible harmful effects to you or your loved ones.
✔– First choices for attempting disease control.
✔– Used when green don't solve the issue.
✔– Only use when blue options have failed and the plant cannot be discarded.
Prevention✔- Keep moisture levels in the soil under control, don't over water. Good plant hygiene is important so remember to remove dead leaves and stems from compost. Air flow is also important.
Manual✔- Removing dead seedlings and be sure the soil is free from dead plant matter. Allow overly damp soil to dry.
Organic✔- Baking Soda Spray can be used to control minor outbreaks of the fungus.
Biological✔- Gliocladium virens is a fungus found in some compost that has been shown to control damping off, though it is not commonly available to the home gardener.
Chemical✔- Copper drenches work well to control damping off in seedling. Ask at your local garden center or hardware store for fungicides containing copper. You can also make your own if you happen to have access to copper dust.
More information on Damping off:
Wikipedia - http://en.wikipedia.org/wiki/Damping_off
How to prevent damping off -http://www.canadiangardening.com/how-to-prevent-damping-off
The Dreaded Damping Off - http://davesgarden.com/guides/articles/view/277/#b