Raising seedlings can be fun and exciting however, just like raising a new born baby; growing seeds to become seedlings can be very challenging and therefore requires careful attention and patience.
In this article, we will highlight some common challenges that occur when raising healthy seedlings and suggest Good Agronomic Practices and other solutions that can help remedy these challenges.
Growing quality transplants require good seeds, a sterile and well drained growing medium (potting mix), proper temperature and moisture conditions, adequate light among others.
Although one is able to have some level of control of environmental conditions in the nursery, challenges can occasionally develop.
Below are some of these challenges, their causes and how best to avoid them or better still combat them:
Poor or erratic germination
Poor or erratic germination of seeds may be caused by improper seeding (for example, sowing too deep), uneven moisture levels and cool temperatures. Ideal air temperature required for germination should be between 18°C-24°C and the ideal media temperature required for germination should be between 16°C-18°C.
Fine (very small) seeds and those seeds which require light for germination should not be sown too deep into the medium. Depths within the range of 2 times the seed diameter will be ideal.
For large seeds, cover medium with additional potting mix to a depth of 1 to 2 times the seed’s diameter.
Uniform moisture levels are required for optimum seed germination and emergence. Media that dries too quickly on the surface could cause roots to become spiral and too much water in media could cause seed rot.
To maintain uniform moisture levels, place clear plastic food wrap (For seeds which require some wavelength of light for germination) or polyethylene over the growing medium. Remove the plastic food wrap or polyethylene as soon as germination occurs.
Tall, Spindly growth (Etiolation)
Tall, spindly growth is a common problem when growing transplants in the nursery house. Poor (insufficient) light and crowded conditions are factors that could contribute to spindly growth.
To avoid this, expose seeds to light immediately after germination to enhance healthy growth of seedlings.
Damping-off is caused by several different fungi. Environmental conditions associated with damping-off are poorly drained potting mix, overcrowding, and excessive watering. Damping-off can be prevented by using clean containers, a sterile, well-drained potting mix, and by following good cultural practices.
Wash previously used containers with disinfectants to avoid the risk of any fungal infection and as much as possible, try to avoid overcrowding when sowing seeds. Flower and vegetable seeds need an evenly moist potting mix for good germination.
Yellowing of leaves
Nutrient deficiency is a likely challenge especially if the potting mix does not have nutrients to support germinated seeds till they are ready to be transplanted. While other potting mixes have nutrients, others do not.
Potting mix that come with nutrients may support seedlings to a point hence the need to complement the nutrition till seedlings are ready for transplanting.
There are various types of fertilizers on the market and ones that are suitable for seedlings should be used. EC of fertilizer solution should not be more than 1milliS and not less than 0.5milliS. Fertilizer with micro nutrients won’t be bad though.
Presence of pests
One of the major factors of high economic importance in agriculture are pests. They disrupt the normal process of plants and to an extent reduce their yield.
Regular scouting in the nursery is important to reduce their infestation. Thrips, aphids, mites and white flies are common pests one could find in the nursery depending on the crop being raised.
As the presence of whiteflies could be visible enough, thrips and aphids could be really difficult to find. However, at the nursery stage, these pests normally find themselves beneath the leaves of growing seedlings.
One could also apply the appropriate pesticides to control them.
While there can be challenges in raising seedlings in the nursery house, farmers can attain quality transplants if they follow good cultural practices.