I agree with @Todd.grobo start over first loss is your best
Coco pod was too wet… A small fan at the bottom could help…
Life cycle and appearance of Damping-off
Pythium belongs to the Oomycetes, a separate group of microorganisms and is therefore not a real fungus. It survives as oospores, resting spores which are resistant to unfavourable conditions, especially dehydration. Germination of the oospores is stimulated by exudates from roots of a susceptible host nearby. The oospores germinate and form so-called sporangia from which subsequently zoospores are produced. Zoospores are spores with flagellae, which enable the spores to move through water. The zoospores are chemically drawn to the growing roots of young plants and move towards them through the soil water. They infect the roots through small wounds, where the side roots are formed or through other similarly damaged spots.
On the infected plant, new sporangia with zoospores are formed, that allow the disease to spread to neighbouring plants.
The zoospores disperse via water. Therefore, this disease spreads most rapidly in wet conditions with a high water content ( > 70%) of the soil or substrate.
Oospores are dispersed when soil particles are moved around by humans or machinery. Pythium can survive very well in the soil or substrate in the absence of plants. Many species are entirely saprophytic, so these do not harm plants.
Pythium affects roots, in particular those of seedlings. Infected plants lag in growth. Seedlings start falling over, also called ‘damping-off’, hence the name damping-off disease. In slightly older plants, the leaves lose their turgor or the leaf tips turn yellow, for example in flower bulbs. At first, the plants recover during the night, but later the plants wilt irreversibly. In potted plants the flower buds fall off. The side roots rot and very little of the root system survives. On the border between air and soil or substrate the plant turns brown. A typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex with a finger nail.
How to prevent Damping-off
Use resistant cultivars or graft on tolerant cultivars
Use clean planting material
Ensure regular growth
Do not provide excess nitrogen since this promotes the disease.
- Prevent high temperatures immediately after planting. Avoid cold and excessive warm irrigation water. Keep the water content of the substrate below 70% and ensure good drainage
- Disinfect recirculating nutrient solutions.
- Increase the distance to the main substrate at the start by using higher substrate blocks for the seedlings.
Prevent plant diseases by optimizing plant potential and crop resilience.