Vol. 9, Issue 4, Part K (2025)

Raising nurseries in open-field conditions using traditional methods is highly labor-intensive and often inefficient. Moreover, seedlings are frequently exposed to various biotic and abiotic stresses such as heavy rainfall, extreme temperatures, diseases and pest infestations, which lead to significant losses in terms of time, labor and financial resources. In contrast, controlled environments such as greenhouses, polyhouses, low tunnel polyhouses, net houses, and shade net structures offer more favorable conditions for producing healthy seedlings. To achieve early crop establishment and reduce production costs, vegetable seedlings are now commonly grown in plug trays under controlled conditions throughout the year. These environments can be customized for small-scale operations with seedlings cultivated in plug trays arranged on racks. Additional requirements such as carbon dioxide, light, humidity, and temperature can be externally regulated to meet optimal growth conditions. Irrigation is typically provided through micro-sprinklers, ensuring uniform moisture distribution. In this system each seedling grows in an individual cell, minimizing competition between plants and promoting uniform development. Plug tray seedlings establish more effectively in the field since their root systems remain intact during transplanting, enhancing plant survival and growth. Fertilizer and water management are also easier to control in protected environments, allowing for precise growth regulation. Furthermore, environmental factors such as heating or cooling can be adjusted according to the specific needs of different seeds, thereby reducing the fluctuations in temperature and moisture that are commonly encountered in open-field conditions.