When transplanting, younger, smaller seedlings usually take longer to get going again than older ones, but yields will be the same. The way seedlings respond to being transplanted at different sizes and ages varies considerably between different species.
A seedling that becomes too old and hard before transplanting will struggle until it can generate a new root system and adjust its growth pattern to its new conditions. With fast-growing, sensitive crops like lettuce, it is far better to err on the young side than to use old, overdeveloped seedlings. crop that takes between 50 and 60 days from transplant to maturity is more likely to give problems if you use overdeveloped plants.
When lettuce seedlings go beyond the ideal transplanting age, they enter survival mode. resulting stress sign is “elbows” in the outer leaves, as the midrib bends inwards. Such plants are unlikely to form the early, big frame necessary for high yield, and uniformity will also be compromised.
Sow seedlings in a good growing medium that will stimulate a strong root system – you can then pull the plants when they’re younger.
The opposite is true for peppers and chillies. Rather err on the side of older seedlings, especially at the beginning of the season in climates like the Highveld where the more tender transplants are vulnerable to wind damage. leaves may scorch at the edges and become distorted, while the stems develop silvery scorching on the windward side.
You can transplant capsicum plants that already have buds, but if the fruits have started to form this will have a detrimental effect on fruit size rather than yield. Removing fruit after transplanting can increase the final fruit size, as will any form of pruning.
With onions, use larger seedlings as they give better yields. Aim at pencil size, usually achieved between 10 and 12 weeks. Leeks are less affected by size, as are spring onions, which are often grown in seedling trays. llium crops are more difficult to grow in seedling trays as the roots aren’t branched.
As nutrients are taken up by the root hairs near the root tips, the plant has to generate new roots to obtain sufficient nutrition.
Organic fertilisers will encourage new root growth.
When transplanting, it is difficult to generalise about the ideal seedling age and development. Many farmers are, however, over-critical of plants considered too old. – Bill Kerr ([email protected] or (016) 366 0616) |fw