Which condition is NOT favorable to the development of seedling diseases?

Which condition is NOT favorable to the development of seedling diseases?

• A. Use of soilless growing medium
• B. Excessive soil moisture
• C. Overcrowded seedling flats
• D. Low soil temperatures before germination

Answer: (A)

Seedling diseases take hold when environmental conditions give pathogens and stressed seedlings an edge. Using a soilless growing medium helps prevent these diseases because such media are typically sterile or clean and drain well, giving the roots strong oxygen access and reducing the presence of soil-borne pathogens that cause damping-off. In contrast, excessive moisture creates the wet, oxygen-poor conditions that many seedling pathogens, like Pythium, thrive in; overcrowded flats trap humidity and reduce airflow, increasing leaf and stem moisture and the chance for spread; and low soil temperatures before germination slow seedling growth and keep seedlings vulnerable as pathogens attack vulnerable tissue. So, the use of a soilless medium is not favorable to the development of seedling diseases, while the other conditions promote them.

Seedling diseases take hold when environmental conditions give pathogens and stressed seedlings an edge. Using a soilless growing medium helps prevent these diseases because such media are typically sterile or clean and drain well, giving the roots strong oxygen access and reducing the presence of soil-borne pathogens that cause damping-off. In contrast, excessive moisture creates the wet, oxygen-poor conditions that many seedling pathogens, like Pythium, thrive in; overcrowded flats trap humidity and reduce airflow, increasing leaf and stem moisture and the chance for spread; and low soil temperatures before germination slow seedling growth and keep seedlings vulnerable as pathogens attack vulnerable tissue. So, the use of a soilless medium is not favorable to the development of seedling diseases, while the other conditions promote them.