Seedlings often die from damping-off disease caused by pathogens in the soil. Symptoms include seed rot before germination, shoot decay before emergence, and stem rot at the soil line. Damping-off is most common in cool, wet soil. It can be managed by planting at optimal times, using disease-free soil, improving drainage, following good cultural practices like thinning plants, and employing sanitation methods such as steam-treating or solarizing soil.