Originally Posted by Maher Mckenna
Every time I try to propagate pine seedlings from seeds most of the seedlings die because of root or stem rotting! I need to know what is this disease?
The disease attacks the stem and/or the roots directly after germination.
These are definitely symptoms of damping off Maher. Do as the others here have suggested. Creating a growing media with plenty of areation spaces between the potting soil particals. There are a number of things you can do to enhance this. I like to use alot of vermiculite with any commercial potting mix which doesn't contain alot of fertilizers or even additions of treated sewage sludge. Keep it as sterile as possible. The seeds themselves should be grown in shallow nursey flats with plenty of air holes in the bottom of the flat, then you can later transfer them directly to the soil or 1 gallon pots or whatever container you wish.
Before I actually plant in that mix, I also premixe some Hydrogen peroxide diluted with water and drench the potting mix. After a day I plant the seed in the pretreated flats of potting soil. Then water as normal. The seed has enough food nutritional material stored in the nut to use as food, though I have fed after a couple of weeks emergence with some seaweed extract or compost tea, but mostly I wait on this after I've transplanted into pots. If I transplant into soil, I always use an inoculum of etcomycorrhiza blend to ensure colonization which will also create an anti-biotics situation of sorts for the young seedling.
One of the benefits of using very areated soil media with generous amounts of vermiculite is that when you transplant, those tiny delicate roots are easier to remove from the mix intact and for the most part undamaged. Here's a famous pic of ultimate pine seedling protection and successes later on in your project.
Good Luck with your project: