Seedlings are delicate and sensitive to external conditions, biotic and abiotic stresses, and any fluctuation or mismanagement may directly kill them. Simultaneously, the growth and development of these seedlings can be significantly regulated and improved by protection from extreme conditions and the provision of all essential factors at the right time.
Seedlings germination and growth are dependent on the type of growing medium, temperature, moisture humidity, winds, light, and air circulation. All these factors must be regulated according to the type of seedlings being germinated and grown. All the seeds and plants have different requirements for germination and growth, so the conditions should be managed as per instructions provided by agricultural extension services according to specific ecological zones and land capability classification.
Requirements of Growing Medium
Seedlings need fluffy and light-medium, and it should be free from any weed seeds, insects, pests, and disease-causing organisms. The use of gardening soil for seedlings is not recommended as it may expose seedlings to various soil-borne diseases. Moist conditions and colder climates favor fungal infection, which may directly kill the seedlings. Therefore, seedlings must be started in sterilized and safe seeding mix or any other healthy and supportive seeding material such as perlite and well-prepared specific compost.
Excessive moisture and dryness also exert adverse effects on seedlings and cause a low germination rate, stunted, and uneven growth. Excessive wetness in a warm climate is an ideal condition for fungal attacks, and the severity of the problem is increased by using an unsterilized seeding mix. Overwatering and underwatering can be avoided by checking the soil moisture content with a finger. Moreover, the wetting of foliage should also be avoided to prevent slow growth and death.
Seedlings require an optimal level of sunlight or any other artificial light for average growth and metabolic activities. However, intense heat and glare can directly kill the seedlings. Therefore, these seedlings should never be kept in direct sunlight during noon and afternoon. Seed sowing in a seeding tray is an ideal approach to protect seedlings from environmental stresses, as these trays can easily be shifted to safe places during weather extremities.
Keeping the seedlings containers north-facing or northeast is an excellent approach to provide enough sunlight for growth and development. Lighting requirements can also be fulfilled by using auxiliary lights; however, the direct contact between plants and lights should be avoided to prevent burning and other types of stresses.
Seedlings also need good air circulation for healthy growth, so vents should be opened for the germinated seeds to allow proper air circulation and reduce humidity. The artificial circulation system can also manage aeration in indoor conditions.
Protection from Fungal Attack
One of the most common reasons behind the death of seedlings is damping off, a fungal disease that negatively affects the plant’s stem at the soil level. It is mainly caused due to poor management conditions and can be avoided by adequately regulating environmental and management factors. The probability of damping-off fungi to affect seedlings is most common in the poor, drained cold soils, and overwatering situations.
Successful seed germination and growth of seedlings are dependent on various environmental and management factors. Maintenance of constant temperature, light, proper air circulation, optimal watering, and fertilizer application, and use of sterile growing media should be critically monitored and managed for healthy and vigorous seedlings growth, and thereby good production.