This archive report was first published on 5 June 2020.
As a farmer in Kiambu, Norah recently discovered the importance of proper seedling care after her onion seedlings were scorched due to low moisture content.
She had applied urea in the morning to promote vegetative growth, but the high nitrogen content in the fertiliser caused the leaves to burn.
According to experts, seedlings are delicate and require careful management practices, including fertiliser application.
When applying fertilisers, it's essential to follow the recommended rates and consider the type of fertiliser used. Urea, for instance, contains 46% nitrogen, which can cause scorching if applied directly to the leaves.
Instead, make furrows or drills on the nursery bed, apply the fertiliser, and cover it with soil. Water the nursery bed immediately to increase plant absorption rates.
It's also crucial to use fertilisers specifically formulated for seedling production to minimise the risk of scorching.
Always read the product label to ensure you're using the correct rates and following the manufacturer's recommendations.
Well-rotten manure should be added to the soil to promote healthy seedlings and reduce the need for top-dressing.
Seedlings are also susceptible to pests and diseases, so it's essential to prevent and control them using cultural and biological methods before resorting to chemicals.
Understanding your local climate and soil conditions is vital in determining the type of nursery to set up. For example, farmers in semi-arid areas should consider using sunken beds to conserve soil moisture and reduce water usage.
Highland areas, on the other hand, may benefit from raised beds, which improve drainage and control soil erosion.
When growing greenhouse crops on a large scale, consider setting up a propagation unit to prevent the introduction of pests and diseases.
Pay attention to germination percentages, as this affects the plant population and ultimately the crop yield.
Excess water can lead to damping off, a fungal disease that affects young seedlings, while overwatering growing media like coco peat and peat moss can cause mould growth.
It's essential to strike a balance between watering and allowing the soil to dry slightly between waterings.
Ensure seedlings receive sufficient light to prevent tall, thin stems from developing.
High temperatures during the dry season can cause rapid growth, so consider erecting a shade net to prevent heat stress.
Finally, maintain good nursery hygiene by collecting waste and disposing of it properly to prevent the introduction of pathogens.
Handle seedlings with care to avoid stem breakages or mechanical injuries that can act as entry points for pathogens.
